ALL Faqs

Five segments fit in a carton roughly 64 x 64 x 64 cm weighing under 2.13 kg. You can ship it overnight, carry it in a car trunk, or strap it to an ATV. Same logistics as the Vertical GeoFlex.

Same options as the Vertical GeoFlex: Campbell Scientific (CR6 or CR1000Xe can log two strings directly; CR350 can log two strings) and DGSI GTecLink wireless data loggers (GeoFlex Node supports up to 50 nodes with external power, or 10 nodes on internal power).

Yes. DGSI offers placement rods (sensorless dummy segments) that install at the end of the string, so you only instrument the specific zone of interest rather than the full casing length. This is the horizontal equivalent of the sensorless nodes offered for the top of the Vertical GeoFlex string.

Either 70 mm or 85 mm diameter inclinometer casing. The casing is installed horizontally through the zone of interest. The system spans that zone, so when the ground moves, the casing moves with it and changes the inclination of the nodes inside.

Up to 200 nodes in 85 mm casing, or up to 50 nodes in 70 mm casing — same as the Vertical GeoFlex.

It’s suited for monitoring ground movement beneath or adjacent to structures where vertical settlement is the concern. Typical applications include:

• Embankment settlement in roadways, levees, and retaining walls
• Monitoring beneath large diameter storage tanks
• Ground movement from tunnel construction
• Landslide early warning above dams, highways, and railroads

The Vertical GeoFlex is better suited where lateral displacement in a borehole is the measurement goal (deep excavations, retaining wall deformation, etc.).

The Horizontal GeoFlex uses the same MEMS sensor nodes as the Vertical GeoFlex but is installed in horizontal casing rather than a vertical borehole. Instead of measuring lateral movement in a borehole, it measures settlement and heave along a horizontal plane. Nodes are still spaced at 50 cm or 2 ft and cumulative deflections produce a profile of the casing. Changes in that profile indicate settlement or upward movement (heave).

Sensly is a cloud-based data management and visualization platform designed for geotechnical, structural, and environmental monitoring. It provides real-time data, automatic alerts, and customizable dashboards, all hosted on a secure cloud infrastructure, accessible through a web browser.

It covers a wide range: dams, bridges, tunnels, railways, pipelines, mines, metro systems, large buildings, power stations, and structures affected by construction. If you’re collecting sensor data and need to monitor it, Sensly is designed for that.

Most data comes in automatically through site dataloggers that transmit to the platform. You can also enter data manually through any web browser if needed.

Data is essentially available in real time. Once data is received, Sensly processes it and publishes results immediately. Calibrated results are displayed on-the-fly, so what you see is always current.

Sensly automatically scans incoming data and sends email or SMS notifications when alarm conditions are triggered. Each sensor includes 4 SMS alerts per month. Additional SMS alerts are available in blocks of 100, invoiced retroactively.

Yes. Sensly is built for multi-project management. All your monitoring projects live in one centralized platform, with customizable access rights per user or project.

Advanced encryption protects your sensitive data. Administrators can configure user access rights to prevent unauthorized changes or access.

Yes. Data can be exported for use in other modeling or analysis software. This also serves as a backup option.

Report creation uses a drag-and-drop interface with live previews. You can also set up automated scheduled reports delivered by email.

You pay per sensor on a monthly basis, billed quarterly in advance based on the agreed maximum number of sensors. There’s a one-time setup fee invoiced at the time of setup. Technical support is included. Customizations and additional modifications are available at an agreed hourly rate.

No. There’s no long-term contract required, and you can cancel at any time.

No. Sensly is fully cloud-based. There’s nothing to install, no servers to maintain, and no IT overhead. Updates happen automatically.

In soft ground applications, you might use a ratio of 6.6 water : 1 cement : 0.4 bentonite. This provides a 28 day compressive strength of about 4 psi. You should also consider using telescoping joints. These will accommodate settlement that would otherwise break the access pipe. They will also improve compliance to the surrounding ground.

In a hard clay, you might use a ratio (by weight) of 2.5 water : 1 cement : 0.3 sodium bentonite. This provides a compressive strength of about 100 psi and a modulus of about 10K psi. The strength and modulus of the grout are controlled mainly by the ratio of water to cement.

There seems to be some confusion over the purpose of the sprung legs. Some people theorize that the legs “couple” the magnet to the surrounding soil. While the legs may provide some “coupling” effect, their true purpose is to hold the magnet in place while the borehole is grouted. After that, we don’t care about the spring force of the legs or their resistance to corrosion.

The soil mass moves up or down and carries the magnet (and the grout and the pipe) along with it. We recommend using a soft grout, but unless the borehole has a large diameter, there is little chance that the grouted hole will become a pile, regardless of its strength.

We have strapped magnets directly to inclinometer casing with telescoping couplings, grouted the hole, and seen perfectly good settlement measurements – without the use of spider magnets at all.

We recommend that you incorporate telescoping sections within the pipe. This will prevent buckling or curvature from occurring in the first place, so this question will never come up.

If you must calculate a radius value, consider the size of the probe, 5/8 inch in diameter by 8 inches long, and the inner diameter of the pipe you will use, which varies with the wall thickness of the pipe.

The following equation (Steinhart-Hart equation) is used to convert ohms to °C for DGSI thermistors.

• Deg C = ((-23.50833439)*((Ohms/1000)^2))+((227.625007)*((Ohms/1000)))+(-341.217356417)

You will need Sondex pipe (corrugated plastic pipe used for drains), Sondex pipe couplings, Sondex sensing rings, Strong cable ties (16 inches or longer) or wire, mastic tape, and vinyl tape. The Sondex couplings are used to join lengths of Sondex pipe. The cable ties or wire are used to secure the Sondex pipe to the bottom of the casing and to hold the Sondex couplings onto the Sondex pipe. The mastic tape an vinyl tape are used to seal the bottom and each coupling so that grout cannot enter in the void between the Sondex pipe and the inclinometer casing. You should also consider installing a grout pipe (or hose) along with the casing and Sondex pipe, since it can be difficult to work a grout pipe between the Sondex pipe and the borehole wall.

1. Cut an 8 foot section of Sondex pipe. This will be attached to the bottom section of inclinometer casing. Cut the remaining Sondex pipe into 10 foot sections.
2. Attach sensing rings to the Sondex pipe at specified intervals. Protect the rings from corrosion with mastic and tape.
3. Prepare the bottom section of casing as usual, then secure the bottom 12 to 18 inches of the 8 foot section of Sondex pipe to the bottom of the casing. This can be difficult because (1) the Sondex pipe is quite strong and larger in diameter than the casing, and (2) the bottom of the Sondex pipe must be sealed against entry of grout. Some people seal the bottom of the Sondex pipe using a Sondex cap, mastic and tape. Then they rivet the Sondex pipe to one side of the casing, and waterproof the rivet holes. Other people do not use the Sondex cap. They slit the bottom of the Sondex pipe to flatten it against the pipe, secure it to the casing with cable ties or wire, and then carefully waterproof it.
4. Lower the first section into the borehole so you can connect the next section. If the borehole is full of water, you must fill the casing and Sondex pipe with water to counter buoyancy.
5. Slide a 10 foot length of Sondex pipe over a 10 foot length of casing. Join the casing, then joint the Sondex pipe. Fit the Sondex coupling onto the butted ends of Sondex pipe. Secure with cable ties and then waterproof the entire coupling.
6. Lower the pipe into the borehole so you can connect the next section. Join the casing, then join the Sondex pipe. Continue until the casing has reached the specified depth.
7. Protect the top of the casing and Sondex pipe from grout spills,
8. Backfill the borehole with grout. We recommend using our inclinometer grout mix.

A Sondex coupling is a short section of drain pipe that is made to link two lengths of Sondex pipe together. The couplings are also corrugated pipe, but their corrugations are spaced so that they key into the Sondex pipe corrugations. They fit tightly and are easy to waterproof. Slope Indicator’s part number is 50801601.

Yes, if you have no other choice. But first check if you can buy the couplings at local stores that sell drain pipe. They are commonly used by builders who have to install drain pipes.

If you must make couplings, cut some 8 to 12 inch lengths of Sondex pipe and slit them. To use, but the two lengths of Sondex pipe together, then fit the coupling onto the joint. Use cable ties to secure the coupling. Then use mastic and tape to waterproof the joint.

The transducer and tubing are completely buried, unlike rod-type settlement devices, so they do not interfere with construction traffic and are less likely to be damaged.

Also, readings are obtained remotely, at the location of the reservoir, again avoiding interruption of construction activity. Tubing can be routed conveniently and does not have to follow a straight line path between transducer and reservoir.

Air bubbles are commonly cited as sources of error, but with proper installation, both factors are easily controlled. By far, the most significant sources of error are barometric pressure (when using a non-vented VW sensor) and temperature variations.

Air bubbles: If air bubbles are present in the liquid, they can cause errors, because air is lighter and compresses more easily than liquid. However, the cell leaves the factory pre-filled with de-aired water. Special headers at the reservoir end of the tubing are overfilled, so the liquid is under pressure and remains under pressure until the final step when the tubing is connected to the reservoir. At connection time, the tubing squirts out liquid rather than sucking in air. Thus, air bubbles are not usually a problem.

Temperature: Temperature problems can be controlled by minimizing the length of tubing that is affected by the ambient temperature. Also the reservoir should be protected from the direct heat of the sun.

Liquid Level Maintenance: It is important to maintain the level of liquid in the reservoir. Typical practice is to replenish evaporated liquid with water each time a reading is taken. To do this, fill the reservoir until the water flows out of the overflow tube. Ordinary water is sufficient. It does not need to be deaired, and it does not need to be mixed with ethylene glycol, since that component of the mix evaporates much slower than the water does.

Barometric pressure: The reservoir is open to atmosphere, so the pressure of the atmosphere acts on the surface of the liquid in the reservoir, and the transducer sees the combined pressure of the column of liquid and the atmosphere. This does not affect the vented VW settlement cell or the pneumatic cell (provided the pneumatic indicator is zeroed at reading time), but it does affect non-vented VW cells. What is the magnitude of these changes? They are many times larger than the resolution, accuracy, and precision of the system. A 1 millibar (0.75 mm Hg) change in atmospheric pressure is equivalent to 10 mm ( 0.4 inches) of water head. Weather fronts bring much greater changes.

The graph at right shows 1.5 days of data from a settlement cell installed at the Isle of Wight. Atmospheric pressure was recorded by an electrical barometer. You can see how the settlement cell tracks changes in the atmosphere. The offset between settlement reading and the barometer reading is the head of water. As you can see, the settlement cell closely tracks the barometer.

The graph at right shows a month of data from a long term test in the laboratory. Barometric pressure was recorded by a VW piezometer. During this month, atmospheric pressure varied over a 20 millibar range and was tracked by an equivalent change (300 mm or 11.8 inches) in head of water even though no settlement actually occurred. Again, the difference between settlement cell reading and the barometer reading is the head of water (about 2.5 meters).

As mentioned above, if you have a vented VW settlement cell or a pneumatic settlement cell, you do not need to concern yourself with barometric pressure. However, if you have a non-vented cell and wish to monitor small settlements, it is necessary to measure barometric pressure and to compensate settlement readings for changes in barometric pressure. Changes in barometric pressure can be very localized, so it is not sufficient to obtain barometer readings from the TV weather report or from the barometer on the office wall. Barometer readings must be obtained on site at the same time as the settlement reading. If you are using a data logger, then it should be programmed to read a barometer at the same time as the cell. If you are obtaining readings manually, you should use a high-quality, hand-held barometer to measure barometric pressure.

You may be interested in the following manuals:

Vented VW Settlement Cell

VW Settlement Cell

A settlement cell is a device used to monitor settlements in embankments, fills, and foundation soil. It reports settlements of a discrete point, as opposed to a settlement profile.

The settlement cell consists of three components: a liquid filled tube, a pressure transducer, and a reservoir of liquid. One end of the tubing is connected to the pressure transducer, which is embedded in the soil. The other end of the tubing is connected to the reservoir, which is located at a higher elevation on stable ground, away from construction activity.

The transducer measures the pressure created by the column of liquid in the tubing. The height of the column is equal to the difference in elevation between the transducer and the reservoir. As the transducer settles with the surrounding soil, the height of the column increases and the transducer measures a higher pressure.

Settlement is calculated by converting the change in pressure to millimeters or inches of liquid head.

The Data Recorder lets you read thermistors (now Slope Indicator’s standard) and RTDs. At the “type:” prompt, you must choose either RTD or thermistor. A reading such as the one you are getting is typical of reading a thermistor as an RTD. Make sure the type is set to thermistor and your readings will probably be normal.

You probably have the standby timer set for 10 or 15 minutes. If you don’t press any keys for that length of time, the Recorder goes into low power standby mode to save battery power. To wake it up, press the Change key. If you want to change your standby timer setting, connect the Recorder to your computer and run the Manager program. Choose Edit Settings – Standby Timer, then enter a standby delay of days, hours, or minutes.

The following formula is valid only with the microstrain reading displayed by the VW Data Recorder. It is not a general purpose formula for converting microstrain to Hz.

F = sqrt ( (microstrain reading + 2030.1) / 0.0007576).

F is the microstrain reading converted to Hz.

You can find this manual here.  Download the Meriam manual.

Try these diagnostic steps.

1.  Make sure the internal tank has adequate pressure and the tank control valve is ON.
2. With no piezometer attached, set the supply pressure regulator to 100 psi.
3. Turn the flow control valve ON, and open the flow rate valve until the digital gauge reaches 100 psi.
4. Turn the flow control valve OFF. The digital gauge should settle around 100 psi. (Supply regulated pressure).
5.  If the the pressure drops below 100 psi, there is indeed a problem with the indicator. If the pressure is maintained at 100 psi, there is probably a problem with the piezometer connection, the piezometer tubing, or the piezometer itself.

Short Instructions for Reading Twin-Tube Piezometer

1. Before leaving office, check that the indicator has enough gas.
2. At the site, turn flow control valve to Vent and zero the pressure gauge.
3. Turn flow control valve Off.
4. Wipe off all dirt and moisture from the transducer tubing and connectors.
5. Connect the quick connect plug to Transducer socket and vent tube to the return flow indicator.
6. Turn tank control valve On, then turn the regulator knob clockwise until pressure reaches the rating of the gauge. 7. Turn flow control valve On.
7. Adjust the flow rate knob so that the pressure reading on the main gauge rises at about 1 PSI per second.
8. Wait until ball in return flow indicator shows a return flow of gas from the transducer, then turn flow control valve Off.
9. Wait until pressure reading stabilizes, then tap gauge and write down reading.
10. To verify, briefly turn flow control valve to Vent, then return to On. This changes the pressure reading. Now take a second, verification reading.

Tangential pressure cells are typically used to monitor stresses in concrete tunnel linings. They are embedded in the concrete, but as the concrete cures, it shrinks and pulls away from the cell. Thus the cell must be repressurized to gain contact with the concrete.

In contrast, radial pressure cells are placed between the concrete lining and the surrounding rock or earth. They are less affected by the curing of the concrete and thus are not typically equipped with a re-pressurizing tube.

If the beeper stops working, we’ll have to fix it at the factory. The beeper could be bad or the transistor that controls the beeper could be bad.

If the light stays on, there is probably water inside the probe. You can check this by opening up the reel and disconnecting one of the wires from the board inside. If the light goes out, check the probe to see if there is water inside. Then dry it out and try to find out why it leaked.

You can contact us to order replacement parts .

Yes. Here are instructions for attaching the probe. Before you order just the replacement probe, check the graduations on your cable. Is it time to replace your cable? Also, if you lost your probe, your cable may have lost some cable with it. In that case, the depth marks will be incorrect when you attach the new probe.

Please contact us and we can help you find the required part.

Yes. Click this link to learn how to return your water level indicator to the factory.

The rule of thumb is that the grout should have a lower permeability than the surrounding soil so that water does not migrate through the grout to the intake area of your standpipe piezometer. The standard practice is to place a bentonite seal above the sand intake zone and then place grout above the seal. Any lag time between changes in pore-water pressure in the ground and changes in the water level in your standpipe is really from the volume of your standpipe and the permeability of the surrounding ground. The grout itself has little influence so long as it prevents migration of water from above. We sometimes recommend the same grout mixes that we use for vw piezometers.

There are two types of piezometers in common use today: standpipe piezometers and diaphragm piezometers (VW or pneumatic). There is no need to saturate standpipe filter tips. Water flows into them easily. VW and pneumatic piezometers do not require saturation either, but there is some air in front of the diaphragm that should be displaced, as explained below:

Diaphragm piezometers, whether VW or pneumatic, contain air between the diaphragm and the filter. For best results, you should displace this air with water. VW piezometers have a removable filter. Pull on the knurled ring to remove the filter. Fill the cavity with water and then replace the filter. Pneumatic piezometers don’t have a removable filter. In this case, you simply direct a slow stream of water into the piezometer or submerge it in a bucket of water and tap the bubbles out.

Some people install the VW piezometer with its filter end up, and our instructions for grouting-in piezometers use this technique. This generally isn’t possible with a pneumatic piezo, since tubing is so stiff. In any case, not much water will drain out of the piezometer so long as it isn’t knocked about during installation.

What happens if there is a small bubble of air? The air will slow the response of the piezo, since the air bubble must deform before it can transmit the pressure of the water. More water must flow into the piezometer to make that happen. Eventually, the air bubble reaches equilibrium and transmits the full pressure of the water. If there is plenty of water available, the slowed response is unlikely to cause much of a problem, and over time the air bubble will disappear. If the piezometer is installed in a low-permeability soil, where less water is available, this process will take longer.

High air entry filters, are generally not appropriate for standpipe or diaphragm piezometers. The high air entry filter relies on the surface tension of water in its pores to sustain a pressure difference between air and water on the filter surface. This keeps air out of the measuring system and allows measurement of matrix soil suction (negative pore-water pressure) that is present in non-saturated, cohesive soils, such as clays in embankments. The high air entry effect is operative only when the filter is saturated with water. When water drains out of the filter, the high-air entry effect disappears.

Generally speaking, only one type of piezometer, the hydraulic piezometer, is capable of maintaining saturation of the filter in non-saturated soils. Diaphragm piezometers and standpipe piezometers do not normally have this capability, and therefore should not be specified with high air entry filters. In addition, most diaphragm piezometers are not calibrated to read high negative pressures and thus, even if the filter properties were intact, would not be able to read those pressure.

A high-air entry filter can be saturated as follows: Remove the filter. Saturate it in deaired water. Replace the filter while holding the piezometer underwater. Bag the piezometer in deaired water to maintain saturation until installation.

To prepare deaired water, boil the water and apply a vacuum or use a device such as a Nold DeAerator, which combines propeller cavitation with a vacuum to deair the water rapidly.

To saturate the filter, place stoppers in the top and bottom of the filter. Place a vent tube through the stopper at the top of the filter. Immerse the filter in deaired water. Water flowing through the filter will displace the air inside the filter, which flows out the vent tube. Allow the filter to remain in the deaired water for 24 hours.

If the soil is saturated and the piezometer is saturated, there should be no problem with clogging because there is no place for the mud to go. Clogging over time implies some kind of flow, but water does not actually flow through the filter. The piezometer measures static hydraulic pressure.

The Push-In Piezometer was designed to be used in very soft soils, especially soils whose structure or hydraulic characteristics would be disturb by drilling. Normal installation procedures for the push-in piezo are to drill within 2 to 5 feet of the target zone and then push the piezometer to the required elevation. Once the push rod is removed, the soil usually collapses and seals the boring. If it does not, you should fill the boring with a bentonite cement grout.

You can use the cone penetrometer rods to push the piezometer inside an existing cone penetrometer hole. The piezometer does not have the same strength as a cone penetrometer and it will be destroyed if
pushed into medium to hard soils. When pushing the piezometer, you must take piezometer readings to be sure that the pore water pressures created when pushing the cone do not exceed the pressure rating of the piezometer, and you will probably have to push very slowly and stop often to let pressures dissipate before continuing.

The online manual is located within the Atlas account and can be accessed in the Help section of your account.

The VW piezometer is a sealed unit that is sensitive to any pressure on its diaphragm. It does not distinguish between pressure of the atmosphere and pressure of the water. It responds to both. However, whether this is important or not depends on your application.

Suppose you suspend the piezometer in a standpipe or water well that is open to atmosphere. The piezometer will report the combined pressure of the water and the atmosphere above the water. If your intention is to monitor the level of water in the well, you must correct for variations in atmospheric pressure.

Now suppose you seal the piezometer in a borehole to monitor pore-water pressure. In this case, the pressure acting on the diaphragm is only the water pressure at that depth. Thus you would probably not correct for variations in atmospheric pressure, even if you later found a relation between atmospheric pressure and pore-water pressure.

You can find more about this subject and how to use barometer readings to make corrections in the VW piezometer manual.

Geokon (and other manufacturers) use digits in their calculations:
digits = Hz^2 / 1000
Therefore, to convert digits to Hertz, multiply digits by 1000 and take the square root of the result.

Atmospheric pressure may vary as much as 34 millibars (0.5 psi) during the day. This is equivalent to apparent water level changes of ±150 mm ( ±6 inches). Even larger variations can occur during stormy weather.

The tests below can be performed with a handheld multimeter.

If there is no reading: Set your handheld multimeter to a low range (less than 5k ohm).

• Measure the resistance between the two VW wires (orange and white-and-orange). A normal reading should be about 300 ohms. If the reading is very high or infinite, the coil is probably burned out (typically from lightning damage). If the reading is very low, the cable is probably damaged.
• Measure the resistance between the temperature sensor wires (blue and white). Thermistors should read about 3000 ohms. RTDs should reading about 2000 ohms. If the reading is very high or infinite, the temperature device is burned out. If the reading is very low, the cable is probably damaged.

If the reading is unstable: Set your handheld multimeter to a high range (10 or 20 M ohm).

• Measure the resistance between a VW wire and a Temp wire. The reading should very high or infinite.
• Measure the resistance between any of the colored wires and the drain (shield) wire. The reading should be very high or infinite.
• Measure the resistance between the shield wires of two VW sensors. The reading should be very high or infinite. A lower reading indicates the presence of a ground loop. Check that each instrument is isolated from the others when it is read. This may require rewiring your multiplexer. Contact the factory for suggestions.
• Some other sources of trouble may be electrical noise from nearby power lines or motors. A over-ranged or shocked instrument may also exhibit these problems.

We have wired a zener diode in parallel with the coil (which is used to pluck the wire). The diode is rated for 1.5 KVA peak pulse, with conduction starting at 10 volts.

Atlas accepts only text files. The most common formats are listed below:

Neither the CR1000X nor the CR350 can read VW sensors directly. A VW module (AVW200) must be used with these loggers.

Choose a formula from the table below:

We usually recommend that the multiplexer be placed close to the CR1000x, but if you must separate them, here are some points to consider:

1. Power: The CR1000x must supply power to drive the relays on the multiplexer, so you must check for a voltage drop caused by the resistance of long cables. See the AM1632 manual for power requirements.

2. Digital Ouput and Pulse: The CR1000x sends a digital signal to reset and clock the relays. The duration and level of this signal can be degraded by long cables. See the AM1632 manual for required voltages.

3. Signal Degradation: The signal from the sensor doesn’t stop at the multiplexer. It continues, unamplified and unfiltered, through the multiplexer all the way to the CR1000x. Long cable lengths are subject to RF noise from the environment and resistance from the cable.

There are two ways to interface a CR1000x to a SCADA system.

1. Make a hardware link via RS232 using the Modbus protocol to interface to HMI (Human Machine Interface) of the SCADA system.
2. Make a software Link using PC-OPC from Campbell. SCADA system has to be compatible with OPC (Ole for Processing Control). Use Loggernet and prefered telemetry option. Loggernet acts as server, with data in Cache. PC-OPC resides on PC and acts a client. PC-OPC goes to server cache, retreives data, then makes it available to HMI, essentiall providing a software ‘bridge’ to HMI.

Discussion of OPC on the Campbell Scientific website

Discussion of SCADA on the Campbell Scientific website

 Yes. There is also a terminal emulator built into the MiniLogger Manager program. Please note that the MiniLogger’s terminal mode is simply for checking the functions of the logger and not intended to support access by other automated means. More about Terminal Mode

Where the cable exits the borehole, we’re planning to route it into PVC pipe.

The standard PVC sweep used by electricians in the construction industry should be fine. These typically have a 6-inch radius. The problem is not the minimum radius itself, but the friction in pulling cable through the bend. Also, it is a good idea to allow a little slack cable for settlement and other movements.

The AWG 22 copper wire in signal cable for piezometers has a nominal resistance of 16 ohms per 1000 feet. The round trip of the wire-pair to and from the thermistor effectively doubles this value to 32 ohms.

The thermistor used in our sensors, as well as in those of most other instrument manufacturers, provides a resistance of 3,000 ohms at 25 degrees C. The thermistor is non-linear, however.

At 25 degrees C, 32 ohms represents about 0.24 degree C, and at 10 degrees C, 32 ohms represents about 0.11 degree C. In other words, the effect of cable length has less effect as the temperature decreases. In either case, though, correction for cable length is probably not needed.

After installing some VW instruments, we had to cut the cables to connect to the data logger. Do we need to adjust the RTD offset, and if so, how can we do this in the field with all the instruments installed?

For many, this question is not relevant. Our VW piezometers are almost always shipped with thermistors rather than RTDs.

For those with older VW piezometers: T he VW sensor calibration record lists an RTD offset based on the original length of the cable that was attached to your sensor. If you change the length of the cable, you must adjust the offset. Use this table to find the change in offset for a given change in cable length. If you have shortened the cable, subtract the change in offset from the original offset. If you have lengthened the cable, add the change in offset to the original offset. Note that the vibrating wire part of the signal (the pressure measurement) is not affected by cable length.

Also, take a look at the most recent version of the VW piezometer manual for a discussion about whether you really need to go through these steps.

You’re probably using the VW Data Recorder and reading a thermistor as an RTD. At the “type” prompt, choose Hz + Thermistor. Then your temperature readings will look normal.

If you are using a Gateway, you should set up the Gateway first. Once the Gateway is operational, each node should be commissioned near to its final installation location. This will allow you to test the radio signal strength between the node and the Gateway to verify you will have successful communication.

Unless you ask for an RTD, we now supply a thermistor.

In previous years, we used the Honeywell TD5A sensor. Here is an Acrobat datasheet listing its calibration characteristics. More general information appears below:

• Sensor Type: 2000 Ohm Silicon RTD
• Temperature Sensing Range: -40 °C to 150 °C (-40 °F to 302 °F)
• Linearity % of Full Scale: ± 0.2%, Typ. -40 °C to +150 °C [-40 °F to 302 °F]
• Supply Voltage: 10 Vdc
• Supply Current (Recommended): 1 mA typ., 2 mA max

Our published instructions assume that users are reading these 2K ohm RTDs using DGSI readouts or the Campbell Scientific CR10X with AVW1 or AVW100 vibrating wire interface.

If you are using another device to read these sensors, obtain a reading in K ohms. Then apply either of the following polynomial coefficients to obtain degrees C:

Solution A: For a range of -10 to +30 C.
Ax2 + Bx + C, where x is the reading in K ohms, and:

A = -23.508334394
B = 227.625006633
C = -341.217356436

Solution B: For a range of -50 to 120 C.

Ax5 + Bx4 + Cx3 + Dx2 + Ex + F, where x is the reading in K ohms, and:

A = 0.95659
B = -12.65962
C = 70.30009
D = -216.32308
E = 483.85218
F = -472.87637

Approximately 240 meters or 800 feet. The datalogger supplies 12 volts, and the transducer requires at least 8 volts. The standard cable used with the 4-20mA transducer has 22 gauge wire so voltage drops about 0.6 volts per 1000 feet.

Please note that we no longer calibrate VW piezometers with this method, however the information is presented here for older piezometers that were calibrated utilizing the old method.

We’ve made an Excel worksheet called: vw-linear-factors-xls. Your calibration record gives frequency readings for 12 pressures. Enter these Hz readings in the frequency column, overwriting existing data. The spreadsheet converts calculates frequency squared readings and then applies Excel slope and offset functions to calculate an m factor and a b factor. These are labelled slope (m) and offset (b). You’ll need WinZip or some other archiving program to unzip the file.

The grout-in method is a faster and easier way to install piezometers. It eliminates the conventional sand filter and the bentonite seal. Instead, the entire borehole is filled with a non-shinking, low permeability grout.

Visit the Theories and Setups page to learn about the grout-in method.

Download the VW Piezometer and Multi-Level VW Piezometer manuals for instructions.

It is not required, but it is helpful. When the Gateway is first powered up, it first checks for a hardwired LAN connection and if it doesn’t find one, then looks for a SIM card. If it does not find either, it goes into standalone mode. This setting can be changed by hard-wiring your PC into the Gateway and changing it or by powering the Gateway off and back on, but it is simpler if it is connected to the network during its initial commissioning.

No. The GTecLink app is used only to connect with the nodes to commission them or to download data from them. The initial commissioning of the Gateway requires that a PC be connected to the Gateway via the USB port on the Gateway.

You will need a standard CAT 5 or CAT 6 ethernet cable and will connect one end to your PC and the other to the Ethernet to USB adapter that was included in the Gateway package. If your PC does not have an ethernet port, you will need to order an additional Ethernet to USB adapter (DGSI p/n 58820530) and will have an adapter on both ends of the ethernet cable. Once you are connected to the Gateway and it is powered on, you will open an internet browser and type http://169.254.0.1 in the address bar.

The user name will be admin and the password will be VMjG6z. This address, user name and password will be the same for any wired connection to any Gateway. Please note that this is NOT the address, user name or password to access the Gateway remotely.

That information is provided on the Gateway Information sheet that was included with your Gateway and is unique to each Gateway.

The standard battery is a size D lithium battery, and should be replaced using the information detailed here. It is a 3.6v lithium battery. The preferred manufacturer is Xeno Energy. They sell the battery under part number #XL-205F (a secondary manufacturer also makes them: Tadiran, under part number #TL-5930 (TL-5930/S)). They can be purchased from several online retailers, including Amazon and Sears, as well as at battery specialist stores.

Updating the firmware for a V-Logger is a simple process.
1. Download and save the V-Logger firmware update here.
2. Connect the logger to your PC via USB and run Logger Manager.
3. Select device type “V Logger” and verify that you have the correct Comm Port selected.
4. If needed, save all data and settings before updating the firmware.
5. Click “Options > Firmware Update”. You should see the following warning:

6. Click “Upload Firmware” and navigate to the firmware update file you saved in Step 1. Select the *.bin file and press OK.
7. The Update window will open, showing the progress of the firmware update.

8. When complete, the “Set Clock” window will open; it may or may not be necessary to update the clock.
9. Confirm the firmware version by clicking “Set Up” on the Logger Manager home page. Click “Retrieve Setup”. Check the Version shown in the general settings. The current version is 2.5 A1.

NOTES:
– Always update with a USB connection. Do not update firmware via a radio link.
– The firmware update will fail if the logger starts to log a reading during the upload. If necessary, change the logging interval so that it will not interfere with the firmware update.

Yes. Data traffic for the Gateway must be enabled through SSH port: TCP 22.

The GeoFlex does not allow for more movement, as both systems will perform until the signal cable  is pulled apart or cut. However, the shorter gauge lengths of the GeoFlex system do increase the reliability of the data once shearing begins. With the typical longer gauge of the IPIs, the shearing is more likely to bend the gauge rod making the displacement results questionable.

Presentation of the data will be exactly the same (with the exception of the higher density of readings for GeoFlex – 2 feet vs 5 or 10 feet). Both systems are plotted as displacement vs. depth. For Horizontal GeoFlex installations, data is plotted as settlement or heave versus horizontal distance rather than depth.”

Both GeoFlex and IPIs can be installed on the same Campbell data logger. The GeoFlex uses an RS485 bus and the IPIs use an analog (RS232) bus.

Multiple GeoFlex strings can be connected to the same Campbell data logger. The number of strings depends on the logger you are using. The CR6 and CR1000X can each handle two strings but do not require the MD-485 module as they have native RS-485 communication.

The IPI sensors have the flexibility of having variable length gauge tubes. They are most typically installed with 5 or 10 feet gauge tubes, but any length can be used down to about 1.5 feet. The GeoFlex system has a 2 feet gauge length at a cost of about the same as 10 feet gauge tubes for the IPIs, thus you achieve a higher density of readings over the same distance for the same cost.

Both the IPIs and the GeoFlex systems can be removed and replaced. Please note that a new baseline will need to be set once the system has been reinstalled. Due to the lighter weight of the system, the GeoFlex is generally considered easier to remove and replace.

Yes. The standard GeoFlex segment consists of five 2 feet nodes (10 feet total) that are connected electrically via a waterproof Seacon connector and mechanically via a pinned universal joint. Once the project is complete the system can be removed and broken down into its 10 feet segments (provided that the shear isn’t so great that they can’t be removed from the casing). Those segments can be used on another project and because each node is addressable, it doesn’t matter in what order the segments are installed on the next project. The Horizontal GeoFlex uses the same durable nodes and connectors with the same redeployment benefit on future projects

Campbell Scientific (CR6 or CR1000Xe can log two strings directly; CRE350 can log two strings) It should be noted that some of these layouts may preclude the reading of other sensor types and you should contact your DGSI representative if you have a more complicated layout.

There are many differences between the two systems that make comparisions difficult, but there is a specific instance where a valid comparison can be made.

Readings cannot be compared directly, even if they are in the same units. Readings from both types of sensor contain an unavoidable offset. The offset is removed from traversing probe data by combining readings from two passes with opposite orientation of the sensor. The two-pass survey is not possible with IPIs, so the embedded offset value remains.

Profile plots cannot be compared directly. Pofile plots (cumulative-deviation plots) are made by accumulating the tilt readings from each interval or sensor. The tilt of the probe or sensor is controlled by its contact with the casing. The contact points are 0.5m apart for the traversing probe, but 1m, 2m, or 3m apart for the IPI sensor. Thus the two instruments will share at most just one contact point and always report different tilt angles.

Profile-Change Plots offer the only opportunity for comparison. These “cumulative displacement” plots are made by comparing current profile with the initial profile. The comparision removes the embedded offsets from the IPI values, but the different points of contact withing the casing are still a factor. That said, if the bottom wheels of the probe and bottom wheels of the IPI are positioned at exactly the bottom depth and the top wheels of the probe and top wheels of the IPI are positioned at exactly the same top depth, the value at the top depth should be comparable. In addition, the overall appearance od the plot should be roughly comparable.

Allow the backfill around the inclinometer to stablize and wait for installation stresses to dissipate. Start recording readings right away, but choose baselines readings after readings have been stable for several days.

Probably not. If sensors are pulled from the casing and then reinstalled, the previous baseline readings are unlikely to compare well. Output will stabilize after some time passes, but even slight differences in the positioning of the sensors will appear as changes (movement) in plots. It is better to establish a new baseline.

Vibration adds noise to the output of any accelerometer-based sensor. The noise degrades the precision of the data, but the mean value of the data can still be used to show trends. Filtering and averaging could possibly improve the data.

Strong vibrations can cause sensors to shift within the casing. The movement may be small, but the result is a change in tilt. The direction and magnitude of the shifts are random, so the resulting data values look erratic. One possible way to prevent shifting of the chain is to fill the casing with sand or soft grout.

There are some notes in the manual, but here are some additional points:

1. Check that the casing is deep enough to contain the chain of sensors. Note that a 60 meter chain will not fit properly in a 60 meter casing. The bottom sensor must not touch the bottom of the casing and the top of the chain should end well below the top of the casing. Also allow some room for the suspension kit at the top. If the casing is not deep enough, shorten one of the gauge tubes. Be sure to note the final length.
2. Fit gauge tubes to each sensor. Test the connection for rigidity.
3. Use cable ties to hold signal cables neatly against the gauge tubes. Signal cables must not touch the walls of the casing.
4. Use cable ties to hold connectors neatly against the gauge tubes. Put one cable tie above and one below the connector to ensure that it is not pulled apart.
5. When the entire chain is in the casing, try lowering it below the intended depth and then pull it back up to the depth. This should put the chain into tension and theoretically shorten the time needed before a baseline reading can be acquired.

DMM for Windows has been replaced by DigiPro2.
The basic version of DigiPro2 is free to use, just as DMM was.

DMM was written in Microsoft VB6. Microsoft discontinued support for VB6 development tools some time ago, making bug fixes and further development nearly impossible. In addition, Microsoft warned that Windows 7 would not support for the VB6 runtime. In fact, they relented and included some minimal VB6 runtime support in Win7, but it is certain that DMM will stop running in some future update of Windows.

For that reason, we developed DigiPro2 to replace both DMM and the original DigiPro. Development took over a year, but it is written in C# and is guaranteed to run on future updates of Windows. We encourage everyone to migrate to DigiPro2 sooner rather than later.

Please take a look at the DataMate Communications FAQ.

DMM for Windows makes this easy. Here’s how:

1. Select the misplaced survey.
2. Click Edit Add to pop up the edit window.
3. Choose the correct installation from the drop down list at the top of the edit window, and click OK. This makes a copy of the survey and places it under the correct installation.
4. Finally, clean up the database. The original survey – the one you copied – is still there. Select it and click the delete button to remove it from the database.

After you do this, check the installation information stored in your Digitilt DataMate. Is it correct?

Make a composite setup database. Here’s how:

To send installations and datasets (surveys) to the DataMate, you make a “setup” database. To make a setup database, simply save your project database as a setup database. DMM makes a copy of the database and then strips out any data, so all that remains is installation information. To add a previous survey to the setup database, view your project database and setup database side by side (Use the Ctrl-T Tile command) and click-drag-and-drop the needed surveys from the project database to the setup database. Just drop the survey anywhere in the white window. It will find its own way home. Now you can close the project database, but keep your setup database open.

Now, open another project database and tile it side by side with your setup database. You’ll be doing click-drag-and-drop operations again. Click-drag-and-drop surveys that you want in the DataMate. The surveys will bring installation information automatically. (Watch out: if you drag an installation, the installation will bring along all of its surveys. So drag a survey, not an installation).

Repeat this for any other installations that you need. Keep in mind that the DataMate has a 40 installation limit and limited space for datasets (surveys).

When the setup database holds the installations and surveys that you need, send the setup to the DataMate. This will cause the DataMate to delete everything that is in its memory and replace it with the contents of the setup database. So be sure that you have retrieved anything that you want from the DataMate before you send the setup.

You can’t do exactly that, but here is a workaround that provides the same result.

1. Choose “DataMate -> Retrieval All.”
2. DMM retrieves data and displays a temporary database (“Data retrieved from DataMate”).
3. Delete any unwanted data from the temporary database.
4. Choose “DataMate ->Send Setup” to transfer the edited database to the DataMate.
5. You’ll see a warning. Click OK to continue.
6. Now the DataMate contains the edited database.

Do it this way: CLICK, then drag and drop. First click on the survey to select it. You’ll see the color change. After the survey is selected, you can drag and drop it. Give it a try: CLICK, drag, and drop. It works.

There are two things to consider: (1) Depth control, and (2) building a composite initial survey.

Depth Control
Slope Indicator’s accuracy specifications assume that the probe can be positioned repeatably within 0.25 inch (6 mm) for each depth in your survey. To achieve this positioning accuracy, you carefully align the depth markers on the control cable with a consistent reference, such as the top of the casing or the cleats on the pulley assembly.

When you add casing, you must establish a new reference. The new reference should be consistent with your original reference, so that the probe will be placed at the same locations in the casing as before. Suppose your initial reading depths were 70, 68, 66 … feet, and then you add four feet of casing. Now the corresponding depths, as measured from the top with your control cable, are 74, 72, 70… feet. However, if you add 5 feet of casing, instead of four, the corresponding depths are 75, 73, 71, etc. This is a problem because the cable has 2-foot graduations. Thus, you should change your top reference, so that you can use cable depths of 75, 72, 50…

Composite Initial Survey
Displacements are calculated by subtracting the initial readings from current readings. Suppose your initial survey has data from 70 feet to 2 feet (35 readings). You may have recorded several surveys using these depths. Then you add casing, so your current survey runs from 74 feet to 2 feet (37 readings). Displacement calculations will fail at the top two depths because you have no initial readings for those depths. The solution is to build a composite initial survey that contains the initial readings of any new casing. Here is how we would build a composite initial survey for our example.

1. Our entail survey has 35 depths (70 feet to 2 feet).

2. Our current survey has 37 depths (74 feet to 2 feet). The two additional readings are at 2 and 4 feet. Select that survey, right click, and choose print from the pop-up menu. You’ll need the values from the top two depths in step 5.

3. Select the initial survey and click the Edit/Add button. The edit dialog pops up.

4. Renumber the existing depths, adding 4 feet to each depth. For example, change 2 to 6, 4 to 8, 6 to 10…and so on.

5. When you get to the bottom, you’ll see a blank line. Enter a depth of 2 and the readings for that depth (from the current survey – the one you printed). Then enter a depth of 4 and the readings for that depth. When you click OK, DMM resorts the data in depth order, so that the two lines of readings that you entered are at the top.

6. You’re done. There is no need to adjust the other surveys. Now you can graph the data in DigiPro. DigiPro always plots each survey from the same bottom depth. The new bottom depth is 74 feet, so all the surveys will be plotted from 74 feet. However, plots with only 35 readings will end at 6 feet, while the plot of the current survey will end at 2 feet. DigiPro will automatically change labels to elevations, if you find that more convenient. (Note that DMM always stores data in depths rather than elevations).

Yes. When you send a “setup” database to the DataMate, it erases all installations (site and installation) and all datasets in the datamate. Then it restores the installations.

You can make a setup database from your project database with “save as”. The save as setup command, strips datasets, leaving only installations. You can also add other installations from other databases to the setup database, if necessary.

This is a hardware problem and is answered on the DataMate FAQ section.

Please download the latest version of DMM. That will probably fix the problem.

There are two ways this can happen. (1) You are accidentally telling the DataMate that you have a metric (or English) system, or (2) the installation information in the DataMate is incorrect.

Case 1: When you start a survey using the DataMate, you choose an installation and then you must step through the installation parameters by pressing the Enter key. If you press the down arrow by mistake, you’ll change the value of that parameter. For example, if you press the down arrow at the Units prompt, you’ll change the value from English to metric or vice versa. It seems logical that you could press the down arrow to scroll through the readings, but you can’t. Always press the Enter key to step through the parameters.

Case 2: You should check that installation information in the DataMate is correct. Switch on the DataMate. Choose Read to display the Read menu. Then choose Installations. Scroll through the list of installations and choose the one that is causing problems. Then step through the installation parameters until you see Units. Set this to English or metric, depending on the type of probe that you have. Press Enter to see the next parameter, Ins Constant. Set this to 20000 for English probes or 25000 to metric probes. Also, check your DMM database to see that probe type and instrument constant are set properly for that installation.

Fixing Incorrectly Recorded Data: If you recorded an English probe with a metric setting in the DataMate, or you recorded a metric probe with an English setting in the DataMate, your data values are not correct. There are three solutions.

1. In DMM, edit each value in the affected survey.

2. In DMM, edit the

Apply a sensitivity correction in DigiPro.

3. Change the Probe Constant for that You can edit each value in the survey and keep , you can or you can change the instrument constant for each affected survey so that computed deviations and displacements will be correct. Here are instructions:

1. Open the project database, choose the appropriate installation.
2. Choose the appropriate survey and click the Edit Add button.
3. Change the value in the “probe constant” field as follows:

The full set flag tells DigiPro how to process the data. A T value indicates a normal two-pass survey, in which each depth has a 0 reading and a 180 reading). The software then combines the two readings and divides by 2. An F value tells the software that there is only a 0 reading and therefore no combining or dividing takes place.

If you end your normal two-pass survey by choosing “Done,” the flag is set to T. However, if you end your survey by pressing Esc, the flag is set to False, even though all the data are present.

Your G-Tilt file may be missing a sensor (probe) serial number.

G-Tilt marks the start of every survey with a *. Count six lines down from the *. You should see a serial number or at least some sort of text. Go through each of your G-Tilt files. Look for the * and count six lines down. Enter the sensor serial number in that 6th line (or just type 12345). Look for additional *s in the file and check that the sixth line after each one has a serial number. You can put any text tha fIf you have multiple surveys in the file, you’ll have to make multiple entries.

*                         —- marks the start of a survey
070685             —- survey date
1327                 —- time hhmm
1400                 —- not used by DMM
Top of clamp   —- not used by DMM
31.2                  —- not used by DMM
12345               —- sensor serial number. line must not be empty

Digipro for Windows has been replaced by DigiPro2.

DigiPro2 replaces both DigiPro1 and DMM.

DigiPro and DMM were written in Microsoft VB6. Microsoft discontinued support for VB6 development tools some time ago, making bug fixes and further development nearly impossible. In addition, Microsoft warned that Windows 7 would not support for the VB6 runtime. In fact, they relented and included some minimal VB6 runtime support in Win7, but it is certain that DigiPro and DMM will stop running in some future update of Windows.

For that reason, we developed DigiPro2 to replace both DMM and DigiPro. Development took over a year, but it is written in C# and is guaranteed to run on future updates of Windows. We encourage everyone to migrate to DigiPro2 sooner rather than later.

You can download a trial version of DigiPro2. It runs in advanced mode for 45 days, then it reverts to a basic version that you can continue to use.

There is no direct way to export graphs. (Note: this is a built -in feature of DigiPro2).

With DigiPro1, you can print graphs to a software “image” printer. The image printer creates a graphic file, which can be emailed, placed in Word, etc.

We have good results with “Zan Image Printer.” It is inexpensive, very convenient to use, and widely available on the internet. We are using Zan to print the DigiPro graphs that we upload to Atlas, our web-based monitoring system.

You can also use a screen capture program, such as “HyperSnap” or “Snag It”. However, screen captures are low resolution, good enough for the computer monitor, but not good enough for printing.

Think of a measuring tape. The tape starts at zero. You don’t record the zero, but it is the origin of your length measurements. Note that the plotted value for the extra depth is always zero.

If your inclinometer installation is 12m deep, and you take readings at half-meter intervals, you will take 23 readings. Your bottom reading is taken at 11.5 meters, but the origin of that interval is at 12 meters. When DigiPro draws the plot, it establishes a zero at 12 meters.

No. Sand backfill has two negatives: it settles, and it washes away.

One west coast department of transportation has studied this. According to them, sand backfill settles for about a month after installation, unless it is well tamped. Unfortunately, it is very difficult to tamp effectively in a small diameter borehole. This settlement means that a good initial reading cannot be obtained for a month after installation. If you obtain the reading earlier, you are likely to detect only movement of the casing within the borehole, rather than movement of the ground.

In ground that has faults sand is sometimes used because grout leaks out the fault. Over time, however, the sand will wash away. Then the casing will move within the borehole and all readings are suspect.

Finally, if there are gaps in backfill (and this goes for grout as well as sand), you’ll find that it takes longer for the inclinometer probe to stabilize. Evidently, movement of the probe in the casing can set up some vibrations.

This is the result of “auto depth-adjustment. With auto-depth adjustment turned on, DigiPro1 correctly plot data points at the top (or bottom) of the measurement interval. Auto-depth is turned on by default.

Why is an adjustment provided? Depth marks on Digitilt control cable are measured from the middle of the inclinometer probe, but deviations and displacements are calculated for the top (or bottom) of an interval.

Metric example: The depth stored with the inclinometer reading is the cable depth of 20 meters, but the top of the interval is actually at 19.75 meters. With auto-depth adjust turned on, the plotted point will be placed correctly on the graph at 19.75 meters, rather than at the cable depth of 20 meters.

English example: The depth stored with the inclinometer reading is the cable depth of 60 feet, but the top of the interval is actually at 59 feet. With auto-depth adjust turned on, the plotted point will be placed on the graph at 59 feet, rather than at the cable depth of 60 feet.

During a survey, the depth of the probe is controlled by aligning depth marks on the control cable to a reference, such as the top of the casing or the top of a pulley assembly. If you want depths on the plot to represent depths below ground surface, then you should enter an offset to adjust the reference to ground surface. That is the purpose of the offset field.

For Depth Offset, enter height of casing above ground level + height of pulley (1 ft or 0.3m)

Metric Example: Suppose the top of the casing is 0.5 meters above ground level. You use a pulley and index the cable to the top of the pulley (add 0.3m). Enter 0.8 m as the depth offset. Labels will show depth below ground surface. .

English Example: The top of the casing is 14 inches (1.17 ft.) above ground level. The pulley assembly adds 1 foot. Enter 2.17 feet for the depth offset. Labels will show depth below ground surface. .

For Elevation Offset, enter ground elevation + casing height + pulley height

Metric Example: Ground elevation is 200 meters above sea level. The top of the casing is 0.4 meters above ground level. The pulley assembly adds 0.3 meters. Enter 200.7 meters for the elevation offset. Labels will be referenced to ground elevation.

English Example: Ground elevation is 1200 feet above sea level.
The top of the casing is 1.5 feet above ground level. The pulley assembly adds 1 foot. Enter 1202.5 feet for the elevation offset. Labels will be referenced to ground elevation.

The time displacement graph requires a single value for each zone. To do this, we first calculate cumulative displacement values for every depth. Then, for each zone, we subtract the value at the bottom depth of the zone from the value at the top depth of the zone. The sign is changed to accommodate top or bottom reference. So the zero point for the plotted value is the value at the bottom of the zone.

In DigiPro1, first plot your data. click on one of the plots to display the properties. Right click in the ‘Data Sets’ window, and select ‘Print plotted data’ from the popup menu. This will print the calculated data used to make the plot.

There is a bug in the correction routine. The bug bites when the 0 and 180 values for a particular depth are exactly the same. For example, the bug will bite when the A0 value and the A180 value at 9.5 meters are both 14. The bug doesn’t bit often because usually the numbers have a different sign and a different value.

The workaround is simple. Use DMM to edit the data file. Change one of the values by 1 unit. For example, change 14 to 15. That makes the problem disappear and does not affect the accuracy of the data.

These templates control the way DigiPro1 processes your inclinometer readings. Use English templates if you have an English-unit inclinometer probe. Use metric templates if you have a metric unit probe. If you need “metric” output from your English-unit inclinometer system, make the conversion in the “Data Units” tab.

Click on “file,” then “options and defaults,” then “page setup.” Choose A4 from the drop-down list. Then click OK. Now, just to ensure that the new default isn’t lost, click on “file” and choose “exit.” Click on “yes” to the “save DigiPro1 defaults” question. Now restart DigiPro1. All new reports will be started with A4 size.

Short Answer: You’ve probably used an English template to create a graph from metric data. Try using a metric template and see if the results are are better. If this doesn’t help, see the long answer below.

Long Answer: A “flag” is stored with each survey. The flag tells DigiPro1 that the survey is either English or Metric. Sometimes, especially with manually entered data, the English/metric information is missing. When this happens, DigiPro1 defaults to English units. To set the flag to metric, close the graph. The “installations and reports” dialog reappears. Right-click on the installation and choose “properties” from the pop-up menu. Change the radio button to “metric” and click OK.

Select the installation, then click “New” and choose “Sample Time – Displacement Graph.” DigiPro1 then plots a graph for the A axis using a single zone. To specify the zones you want, click on the graph to call up the report properties dialog. Then click on the new “Zones” tab. You can specify up to five zones, choosing a start depth (shallower) and a stop depth (deeper) for each zone. You will probably want to click on the “Datasets” tab to select more datasets.

Click on “File” – “Options and Defaults” – “Preferences.” You’ll see a band of 8 colors. Click on the color you want to change and choose a different color from the pop-up color dialog. The change takes effect when you close your report and open it up again. Later, when you quit DigiPro1, be sure to say “yes” to the prompt “Save DigiPro1 Defaults.”

Just right-click on the dataset that you want to mark as initial, choose “Mark as initial” from the pop-up menu, and click apply. All datasets earlier than the initial are then ignored.

Yes, but you’ll have to do some minor editing in DMM. 

Check to see if the file is marked “Read-Only.” Using Windows Explorer, select the database, then click the right mouse button and choose Properties. You can find file attributes at the bottom of the properties dialog. Remove the checkmark from Read Only. You may have to click the box more than once. Now DMM and DigiPro1 can open the database.

The manual for the horizontal probe provides some instructions for installing horizontal casing in soil. Most of these instructions will apply to your application as well. For example,

• The traversing probe requires 70 or 85 mm (2.75 or 3.34″) casing.
• One set of grooves must be vertical. This is essential. Check for this during installation.
• Telescoping sections are not recommended or needed.
• Casing should be flat and straight. It’s ok to build in an inclination for drainage.
• A pull cable is required to pull the probe to the far end. Install the cable as you assemble the casing.

For your application, also consider this:

• Support the casing well, at least every 5 feet and under couplings. Tie the casing to the supports so that it does not float upwards when the concrete is poured. Wrap the joints with tape to make sure grout does not enter.
• Remember that the casing is plastic and weaker than steel. Avoid pouring concrete directly onto the casing.
• The casing is plastic and will start deforming if temperatures exceed 82° C ( 190° F). If the ambient temperature is above 26° C (80° F), you may need to fill the casing with cool water at the same time as you are pouring concrete. Make sure that the casing is supported by the concrete before filling it. There are other ways to avoid high temperatures as well, such as icing the concrete.

Error 11 is caused by a problem in your data file, usually a missing instrument constant. Open your database with DMM. Click on an installation, then click the survey list tab. Check every survey has an instrument constant. The survey that is missing the constant is causing the problem. Use Edit/Add to enter the constant.

DigiPro2 es distribuido como una versión de prueba. La versión de prueba en sus primeros 45 días, después de la instalación, trabaja con todas sus características y ventajas activadas. Después de este periodo, la versión avanzada se transforma a la versión básica.

La versión básica de DigiPro2 es gratis y permite el manejo de bases de datos y crear gráficos primarios. DigiPro2 puede ser convertido en cualquier momento a la versión avanzada con solo ingresar una clave valida.

Claves para activar DigiPro2 avanzado deben ser compradas. Para adquirir una licencia, contacte a DGSI o cualquiera de sus distribuidores. Cuando se compra una licencia nosotros ingresamos información de su compañía en el ordenador de licencias de DGSI y este emite un código que genera la clave. Después de esto le enviaremos el código de la clave por correo electrónico. Si usted compra una licencia de un distribuidor, la clave será enviad al distribuidor y ellos se la enviaran a usuario final.

Los paso que siguen, explican como ingresa y manejar la clave.

Como Instalar la Clave de la LicenciaPaso 1: Comience DigiPro2 y haga clic en “License”. Después, DigiPro2 mostrará el cuadro de diálogo

Paso 2: Copie la clave del correo electrónico que recibió y péquelo en el cuadro “Licence Key”. De aquí haga clic en “Install”

Paso 3: DigiPro2 valida el código de la clave a través del Internet. Cuando la validación se completa usted vera el mensaje siguiente ” License Installed” en el área llamada “License Status.”Hacer clic en “Close” para completar el proceso.

Como Trasladar la Licencia

Si es necesario trasladar la licencia del ordenador original a uno nuevo hay que seguir los siguientes pasos:

1. Estar seguro que usted tiene la clave que se le envió originalmente mediante correo electrónico.
2. Comience DigiPro2 en el ordenador antiguo.
3. Hacer Clic en “License”; en “Unistall License” escoja “Yes”. Al hacer esto, DigiPro2 se convierte a la versión básica en este ordenador.
4. Instale DigiPro2 en el ordenador nuevo. Pegue la clave en “License Key” de la misma forma que se explica arriba.

DigiPro2 is distributed as a trial version. The trial version starts with advanced features enabled for 30 days. After 30 days, the advanced features are disabled and only basic features remain.

DigiPro2 “basic” is free to use and still provides database management and simple plotting. DigiPro2 basic can be converted to “advanced” at any time by entering an authenticated license key.

The DigiPro2 licensing system has changed. The new licensing system requires the user to download the software from our website and then select from the following options:

• Request a new license
• I have a license file
• Start a trial (30 days)

When you select “Request a new license” the computer will generate a file named LicenseRequest.lic which will need to be emailed to support@slope.com. When you email the license request, please also include your existing license key or your order/invoice number, as applicable.

Upon receipt, DGSI staff will validate the license and send it back to the user. The user will open the program and navigate to the License screen, select “I have a license file” and then click Browse to attach the validated license. Please note that the validated license will ONLY work on the computer from which the license request file was generated. For each current valid license, we will issue one free replacement license.

DigiPro2 is an inclinometer processing and graphing program. It replaces the original DigiPro and also DMM.

DigiPro2 can import surveys from DMM databases, so there is no loss of data when you switch. You can also import data from GTILT and other formats.

A1: To convert a DMM database: Click File -> Convert DMM Database and choose your mdb file. DigiPro2 then creates a new .dpw database with the same name and same contents.

A2: To import DMM data into an existing .dpw database, click File -> Import -> DMM Data.

Yes. DigiPro2 replaces DMM. You can find complete instructions on page 7 in the DigiPro2 manual. (O aqui para español.) Here is a summary of the steps:

1. Connect DataMate to PC, switch on, and choose Comm.
2. Start DigiPro2 and open a database (Open a dpw database, not an .mdb database).
3. Click DataMate > Retrieve All or Retrieve New (same as DMM)

“Invalid License Key” (Clave de Licencia Invalida)

La razón más común de este mensaje es debido a que la clave ha sido usada demasiadas veces. Contacte a DGSI o a su distribuidor para corregir este problema.

“Authentication Error” (Error de Verificación)

Este error aparece cuando su ordenador no puede contactar el servidor de DGSI vía el Internet.

Para corregir este error, chequee que está conectado al Internet y que este está trabajando apropiadamente. Si todo está bien, es posible que su barrera de seguridad (fire wall) en su ordenador este bloqueando la comunicación con el servidor de DGSI. El servidor de DGSI usa el puerto 2145. Si ese puerto está bloqueado y no puede ser habilitado usted deberá usar el método explicado abajo.

1. Si usted ve el error “Authentication Error” haga clic en “Yes” para crear un archivo para la licencia.
2. El cuadro de dialogo “Save As” aparecerá. Especificar una ruta y ubicación a donde se guardará este archivo. Recomendamos cambiar el nombre sugerido (License.lic) con uno que usted pueda fácilmente recordar y relacionar con su ordenador. Esto es especialmente importante si tiene que instalar DidigPro2 en varios ordenadores. Tuene que repetir el proceso en cada ordenador.
3. Cuando este creado este archivo, adjúntelo a un correo electrónico y envíelo a slolutions@slope.com o a su distribuidor.
4. De regreso le enviaremos un correo electrónico con el archivo de verificación de licencia adjuntado.
5. Guarde el archivo en el ordenador que tiene instalado DigiPro2.
6. Comience DigiPro2 y haga clic en “License.”
7. Haga clic en “load license”, navegue a la ubicación a donde guardo el archivo del paso 5 y haga clic en “Open”. DigiPro cambia la condición de DigiPro2 a “License Installed.”

 Please visit this page: Detailed Feature Comparison

Step1: Start DigiPro2 and click the License button. DigiPro2 then displays the license dialog

Step 2: Select “I have a license file”. Click “Browse” and navigate to the location you downloaded and saved the authenticated license key. Click “Install”.

Unhandled Exception

You must have permissions on your computer to access the C:\ProgramData\DigiPro2 folder. When you install your authenticated license, the program places the license in this folder. When you open the program after that, it looks for the license file to validate the installation. If you don’t have permission to access this folder, then the Advanced Features will never be turned on. You may need to contact your IT department to gain access to the folder or run the program as an administrator.

Once you have received your order acknowledgment, please send your LicenseRequest.lic file along with the Order Acknowledgement number to Support@dgeslope.com.

The trial version runs in advanced mode for 30 days. After that, it reverts to “basic” mode unless you purchase a license key. The basic version still provides database management and simple plotting, but all advanced features, including reports, are disabled. Entering a license key restores the advanced features, including the ability to open reports.

Think of a measuring tape. The tape starts at zero. You don’t record the zero, but it is the origin of your length measurements. Note that the plotted value for the extra depth is always zero. If your inclinometer installation is 12m deep, and you take readings at half-meter intervals, you will take 23 readings. Your bottom reading is taken at 11.5 meters, but the origin of that interval is at 12 meters. When DigiPro draws the plot, it establishes a zero at 12 meters.

Here are some instructions to get you started. A later version of the manual will document this fully.

1. Identify the zones of interest using a change plot.
2. Display the time plot.
3. Right click on the plot and choose Define Zones.
4. Enter top depth and bottom depth for as many zones as you need, then click OK.
5. Next, right-click on the B-axis plot and choose Copy settings.
6. Check Zones and then click OK.

This is a two part process. The first part is entering settlement data for a particular inclinometer. The second part is applying settlement corrections to a particular inclinometer surveys.

Entering settlement data

1. Right click the Inclinometer. Select “Add Survey”. The survey dialog appears.

2. Set Survey Type to “Settlement”. Enter the initial settlement survey depths. Click “OK” to save the initial settlement survey (these are depths with units in meters or feet, as appropriate).

3. When you have new settlement data, repeat the steps above. You need a least two settlement surveys before you can apply a correction.

Applying a settlement correction

Now that you have settlement data in the system, DigiPro can make corrections.

1. Click on the Inclinometer Survey to be corrected. Click “Tools”, then “Apply Settlement Correction”.

2. The Settlement correction dialog appears. By default, the earliest and latest settlement surveys will be selected as initial and current. Click OK.

The change (settlement or heave) between the initial and current settlement surveys will be calculated and applied to the selected Inclinometer Survey. The original survey will be left unchanged, and a new corrected Inclinometer survey will be created with the same date but with minutes and seconds set to 59:59.

Here are some instructions to get you started. A later version of the manual will document this fully.

1. Select an inclinometer.
2. Click Edit > Add/Edit Boring Log. A dialog appears.
3. Right-click in the gray box to add a zone.
4. Enter legend, top depth, and bottom depth in the text area below.
5. Choose texture and color, then click X to close and choose save.
6. Generate a plot.

1. Create a plot in DigiPro2. Make any corrections needed. Decide
2. Open Plot Options in the settings panel.
3. Double click “Use Elevations” to make it “True”. This works even if no elevations are entered.
4. Click Export and choose a path and filename. Set file type to ” Atlas files (.dat).”
5. Set the upload program (such as FTP Scheduler) to upload the file.
6. Enter the inclinometer as a “sensor” in Atlas with A and B channels. Use the data file names in step 4.
7. Create a vertical profile plot in Atlas. You must make one plot for the A and one plot for the B. You can display the two plots side by side by creating a “side by side” plot.

Templates were stored in a special “templates.mdb” file in the DigiPro\system folder and were not part of the normal inclinometer database file.

1. Copy the file “c:\program files\digipro\system\templates.mdb” to your document directory.
2. Open DigiPro2 and use the DMM database import function to import the template.mdb file.

A1: Tap Settings > Application Manager > Digitilt Reader > Force Close. Then return to the home screen and restart the Digitilt Reader app.

A2: Are you running the Reader app on other tablets too? One of them may be connected. To break the connection, switch off that Reel’s Bluetooth.

Yes. The settings can be adjusted to the way you work and also variables at the site (such as a lot of ground vibration).

1. Turn sound off, so you can concentrate on the action rather than the record sound.
2. Tap Options > Survey Control.
3. Make a change. It is best to experiment with just one change at a time rather than making lots of changes all at once.
4. Tap “done” – the checkmark – to save the change.

Here are some suggestions:

• If the Reader depth is shallower than your cable depth, try setting “pull lockout” to 3 or a higher number. This tells the Reader to delay longer before accepting new input. You’ll see that the “saved” message appears for 3 seconds now. Experiment to find the right lockout timing. New users need a longer lockout, while expert users may prefer a shorter lockout.
• If your cable depth is shallower than your Reader depth, try setting “motion” to a lower number, for example 80. Users who pull slowly need a lower number. Users who pull quickly can use a higher number.
• If there is a lot of ground vibration at your site, you might need to use “Tap” mode, but you could try setting “motion” to a higher number and then pull quickly rather than slowly. The higher number decreases sensitivity to the ground motion, so you must accelerate the probe faster so that a pull can be detected.

Download it from the Google Play Store.

1. Tap the Google Play icon on your Android device.
2. Search for Digitilt Reader.
3. Tap Install.
4. Tap “Accept and Download” after reviewing permissions.
5. The Digitilt Reader icon appears in your app drawer. If it does not appear on your home screen, open the app drawer to find the icon. Then tap and hold the icon. When you release, it will be placed on one of your home screens.

Follow the steps below.

1. Download this file to your PC: Digitilt Reader APK. (APK is an Android setup file).
2. Connect the Android device to the PC using the USB cable supplied with the Android device.
3. Use Windows Explorer on your PC to copy the APK file to the Android device. Any location is ok, but remember where you saved the file. After copying the file, disconnect the device.
4. Open a File Manager program on your Android device – for example, My Files on a Samsung device.
5. Locate the apk file and tap it. You may need to authorize the installation of applications from sources other than the Google Play Store.
6. Now you can run the Reader app.

Download an alternate keyboard from the Google Play Store (such as the free Google Keyboard) that does have a decimal separator. You will need to set this as your default keyboard for your tablet.

Set default “display units” in the inclinometer settings. If you are taking readings and want to see a different unit, tap the unit label. For example, if the unit label is mm, tap the mm to toggle Digi-Metric or Digi-Native.

No. Pairing is a one-time operation in which Reader and Reel exchange Bluetooth IDs. After that, the Reader remembers the Reel, even if you switch Bluetooth off.

Yes, if you upgrade your DigiPro software to DigiPro2. DigiPro2 can import all of your classic surveys. After that, you can keep AT surveys and Classic surveys in the same project database; however, it is not recommended that surveys taken with one probe (classic or AT) be compared to initial readings taken by another probe (classic or AT).

No. The Classic probe is analog and the AT probe is digital. They have different power requirements and different readouts. Thus they are not freely interchangeable.

We do not recommend interchanging probes, in any case. Differences between probes are amplified by tilt and curvature of the casing, even with probes of the same type. The AT system features new cable marks and a cable gate, which introduces even more differences.

Best Practice: Some users obtain separate baseline surveys with two systems: an “active” system and a “backup” system. Subsequent surveys are taken with active system only. If that system fails, the backup system and its baseline survey can be used to continued the monitoring program. In this scenario, AT and classic systems would work well as either active or backup systems.

Yes, there are three main differences:

• AT cables are lighter and easier to carry, but permanently attached to the cable reel.
• AT cable marks are designed to work with a cable gate.
• AT cable marks are measured from the top wheels of the probe, rather than the middle of the probe.

The AT system displays readings as mm or inches of tilt, and this reading applies at the depth of the top wheels. Scroll downwards to see a technical explanation with a graphic. Classic cable marks are measured from the middle of the probe, but this has some unexpected effects when readings are plotted:

Metric Plots:

• AT system: A reading taken at 10 m is correctly plotted at 10 m, as you would expect.
• Classic system: A reading taken at 10 m is correctly plotted at 9.75 m, which you would not expect.

English Plots:

• AT system: A reading taken at 30 feet is correctly plotted at 30 feet, as you would expect.
• Classic system: A reading taken at 30 feet is correctly plotted at 29 feet, which you would not expect.

The cable gate provides an easy way to align cable marks to the top of the casing. With the pulley assembly, depth marks are typically aligned with the cleats at the top of the pulley, which is 0.3m or 1 foot above the top of the casing.

Metric Depths:

• AT system: When the cable mark shows 10 m, the probe is 10 m down hole.
• Classic system: When the cable mark shows 10 m, the probe is only 9.7 m down hole.

English Depths:

• AT system: When the cable mark shows 30 feet, the probe is 30 feet down hole.
• Classic system: When the cable mark shows 30 feet, the probe is only 29 feet down hole.

Summary: If classic surveys are not corrected for the pulley offset and the middle of the probe measurements, plots will show displacements a full interval deeper than they actually are.

The drawing shows a probe in tilted casing. We can overlay the probe with a right triangle. The vertical side of the triangle is the gravity vector. The hypotenuse of the triangle is the gauge length – the distance between the top and bottom wheels of the probe. You can see the tilt angle at the bottom of the triangle. The tilt angle applies anywhere along the length of L. The Digitilt DataMate displays readings in sine units (the sine of the angle of tilt), which also apply anywhere along the length of L. The AT Reader records sine units, but when it displays a reading, it multiplies the sine value by L, the gauge length of the sensor (500mm or 24 inches) to display a reading in mm or inches. This value applies only at the top of the triangle, as in the illustration, which is the elevation of the top wheels of the probe. Thus we measure cable marks from the top wheels of the probe, so that the reading is shown at the proper depth.

Yes. We strongly recommend that you start a new baseline, whether the replacement system is classic or AT. By starting a new baseline, you avoid the complications (rotation and sensitivity differences) that can appear when one probe is substituted for another. If starting a new baseline is not acceptable, you can achieve a better comparison by ensuring that the AT probe is positioned at the same elevation that the classic probe was. This would seem to be an easy task, but there are some details to consider. 

Different Indexes: To control the elevation of the probe, we align depth marks on the cable to an index. The AT system uses a cable gate. The cable gate aligns depth marks with the top of the casing, so we can say that the AT index is the top of the casing. With Classic systems, the index is often the top of the pulley assembly, which is 1 foot (0.3m) above the top of the casing. Thus for a given depth mark, the Classic

probe is actually 1 foot (0.3m) higher than the AT probe. 

Different Depth Marks: Depth marks on AT cable are measured from the top wheels of the probe. Depth marks on Classic cable are measured from the middle of the probe. The difference is 1 foot with English systems and 0.25m with metric systems. Thus for a given depth mark, the top wheels of the Classic probe are 1 foot (0.25m) higher than the elevation of the top wheels of the AT probe. 

Summary: Assuming that the pulley assembly is used as the index, the top wheels of the Classic probe are a 2 feet or 0.55m) higher than the the top wheels of the AT probe. Even if the Classic system uses the top of the casing as the index, the top wheels of the Classic probe are still 1 foot or 0.25m higher than the AT probe. If your Classic survey used a pulley assembly as index: Start the AT survey a full interval (0.5m or 2 feet ) shallower than the Classic survey. Also, edit the Classic survey to remove any depths shallower than 1m or 4 feet. If your Classic survey used the top of the casing as index: Make a short casing extension (0.25m for metric systems or 1 foot for English systems) to use with the AT cable gate. Now the AT probe will be held at the same depths as the Classic probe.

No, because that just isn’t practical. Here’s a suggestion:

1. Make a precise measurement of offset before you leave the office. Write down the measurements per the instructions in the manual.
2. Now you’re at the first inclinometer. Insert the instrument and take a measurement at the top of the hole. Note the inclinometer ID and measurement value on paper. Then do the normal spiral survey.
3. Now you’re at the next inclinometer. Repeat the steps above. You’ll probably see a slightly different value for the top of hole measurement. You shouldn’t see a huge difference. Be sure to note the inclinometer and the value. You can calculate the change later.
4. When you return to the office to crunch the data, you’ll have to enter the precise offset measurement. For the first inclinometer, you’ll enter the measurement as obtained at the office. For the other inclinometers, enter the precise measurement + the change from the top-of-hole measurement.

The spiral routine requires a minimum of two passes through the casing, but better results are obtained by four passes through the casing: the first oriented in the A0 direction, the second in the A180 direction, the third in the B0 direction, and the last in the B180 direction.

With English spiral sensors, readings must be taken at depths that are multiples of 5 feet. With metric spiral sensors, readings must be taken at depths that are multiples of 1.5 meters. This requirement affects the way you must record readings with the Digitilt DataMate. See instructions below.

Click this link to download the manual: Spiral Sensor Manual. Here are some abbreviated instructions.

1. Lower the spiral sensor to the bottom of the casing. Note the cable depth.

2. Choose Read – Record. Choose an installation, and step through the installation parameters.

3. Set Sens Type to Spiral.

4. Set Start depth to the multiple of 5 feet or 1.5 meters nearest to the cable depth that you noted in step 1. (For example, if the cable depth is 159 feet, set the start depth to 160 feet.)

5. Set End depth to 5 feet or 1.5 meters.

6. Take the first reading without moving the sensor. (In our example, the DataMate displays a start depth of 160 feet, even though the sensor is actually at 159 feet. The reading will be labelled 160 feet. This difference in depth has very little, if any, effect on the reading.)

7. The DataMake displays the next depth. This time raise the sensor to the indicated depth. (In our example, example, the DataMate prompts 155 feet. Raise the sensor to 155 feet and record the reading.

8. Continue taking readings at the prompted depths, rotate the sensor 180 degrees for the second pass. Then take readings in the B0 groove and finally in the B180 groove.

DigiPro2 can generate a graph from your spiral data. Use the graph to decide if the spiral is significant enough to affect your readings. If you decide to use the spiral data, DigiPro2 can generate a spiral corrections dataset. To generate a spiral corrections dataset, DigiPro2 needs the spiral data, the inclinometer ID (the spiral routine looks for the deepest and shallowest depth and the interval), and the precise offset measurement, number of passes, and the cable offset if available. See Spiral Correction in the DigiPro2 manual.

1. Are you using up-to-date software? Check our downloads page for DigiPro2.
2. Check your interface cable. If your DataMate has an I/O socket, you must use a cable that has a DB9 connector. If your DataMate has a USB socket, you must use a cable that has a USB connector. They are not interchangeable.
3. Can you connect the interface cable to your PC? Most modern PCs have only USB ports. If your cable has a DB9 connector, you must use a serial-to-USB adaptor. If your adapter doesn’t work, try downloading a new driver from the manufacturer’s website.We currently stock a USB-to-serial adapter from Sabrent. Our part number is 56704018. The most current driver can be downloaded here.
4. Check that the DataMate displays: “Waiting for PC.” (Choose Comm on the DataMate menu). When you click retrieve new or retrieve all, the DataMate should display “Linked to PC.” If you don’t see that message, try step 5 below. If you do see that message, but then it returns to “Waiting for PC,” the cable may be bad.
5. Check the comm menu in DigiPro 2 and DMM. It shows what comm ports are available. Choose a different port. If you are using a serial-to USB adaptor, try the comm port with the highest number.
6. The PC software remembers which comm port number was used last. If your DataMates use different cables, they also use different comm ports. The software might remember the “wrong” comm port number so it can’t communicate. Go to the comm menu to select the correct comm port number.

Is your USB Driver working? Here is a simple test.

1. Switch off the DataMate. You can leave the USB cable connected.
2. Open the comm menu in DigiPro 2 or DMM. You’ll see a list of comm ports. Check their numbers.
3. Close the comm menu.
4. Switch on the DataMate (and plug in the USB cable if you disconnected it)..
5. Open the comm menu in DigiPro 2 or DMM. Look at the list. Do you see a new comm port number?

• If you see a new comm port, use that one with the DataMate.
• If you don’t see a new comm port number, the driver is not working. Follow the steps below.

Identify the problem: USB chip or USB driver?

1. Open the device manager via the control panel. Or use the command line like this: in Win XP, click Run and enter ” devmgmt.msc.” In Win 7, enter “devmgmt.msc” in the search field.
2. The device manager appears. Look for a yellow warning triangle. It is probably labelled “Other.”
3. Right click on the item. Choose Properties.
4. The Properties dialog appears. Choose the “Details” tab.
5. At the top of the Details tab, there is a droplist. Click the droplist and choose “Hardware Ids.”
6. Two lines of text appear.

• If you see “BE40” embedded in either line, you must update the USB chip in the DataMate.
• If you see “6001” embedded, you must update the latest USB driver. See below.

Installing the latest USB Driver

1. Click the Driver Tab.
2. Click the Update Driver button.
3. Allow Windows to search the internet and update the driver automatically:

• Win 7 searches the internet and installs the driver.
• Win XP shows a dialog. Choose yes to allow a search and click Next. Then choose yes to allow automatic installation, and click Next.
• If Windows has problems installing this driver, use the alternative method below.

Alternative method for installing the USB Driver

1. Download the installer program: CDM21216_Setup.exe.
2. Run the installer program.

Use the drawing at right. Wire colors may vary, so they are not listed. You’ll have to look at both connectors to identify the wire colors. Note that this cable works only with the original DataMate.

Use the drawing at right. Wire colors may vary, so they are not listed. You’ll have to look at both connectors to identify the wire colors. Note that this cable works only with the DataMate II.

Yes. We recommend that everyone migrate to DigiPro2. Here’s why:

DigiPro and DMM were written in Microsoft VB6. Microsoft discontinued support for VB6 development tools some time ago, making bug fixes and further development nearly impossible. In addition, Microsoft warned that Windows 7 would not support for the VB6 runtime. In fact, they relented and included some VB6 runtime support in Win7, but it is certain that DigiPro and DMM will stop running in some future update of Windows.

For that reason, we developed DigiPro2 to replace both DMM and DigiPro. Development took over a year, but it is written in C# and is guaranteed to run on future updates of Windows. We encourage everyone to migrate to DigiPro2 sooner rather than later.

Follow these steps to navigate to the Contrast menu.

1. Switch power off and then on again.  (The hidden cursor is now on Read)
2. Press the right-arrow key 3 times, then press Enter. (Cursor is now on Utilities)
3. Press the right-arrow key 5 times, then press Enter. (Cursor is now on Contrast)
4. Press down arrow until characters reappear.

DataMates manufactured before 2009 were supplied with a Sonnenschein A206-6.5S battery. DataMates manufactured from 2009 are supplied with a EnerSys NP7-6 battery.

We switched to the EnerSys NP7-6 battery because the A206-6.5S batteries are now difficult to obtain. They will become completely unavailable sometime in 2010.

If you must replace an older Sonnenschein battery, please ask us if we have any in stock. If we do not have any in stock, then we can supply the EnerSys NP7-6 battery. You will also need to buy a new battery bracket, since the EnerSys battery has a differerent size and shape. Note that the combined cost of the battery and the bracket is not much different from the cost of the Sonnenschein battery by itself.

Normally, you don’t have to do this. However, if a technician at Slope Indicator has recommended the reset, follow these instructions: Resetting the DataMate . Be sure to ground yourself and the DataMate to prevent damage from static discharges.

Short Answer: Nothing is wrong. You don’t need to do anything.

If your DataMate has a firmware version dated 1997 or earlier, there is no firmware upgrade available. Simply ignore the message. To see the firmware version, switch on the DataMate. The second line displays the firmware version (a date).

If your DataMate has a firmware version dated 2005 or later, a firmware upgrade is available. Contact Slope Indicator about that.

Long Answer: The DataMate and the DMM software on the PC exchange “version codes” when they begin to communicate. If the codes do not match, either the DataMate or the PC will complain.

We made a new version of DMM software to support the newest version of the DataMate, so the DMM version code had to be changed. The new DMM software supports both the old DataMate (firmware version 1997 and earlier) and the new DataMate (firmware version 2005 and later).

When an older DataMate receives the new version code, it displays the “firmware upgrade” message. Usually the message disappears quickly, but if the DataMate is waiting for a response from the PC, then the message will be displayed long enough for you to read it. If you are looking at your PC, you won’t see the message at all. Here are the conditions when you can see the message:

• When you retrieve data from the DataMate, the message appears, but goes away quickly. Some people will never see this one.
• When you send data to the DataMate, the message stays on the display, because the DataMate is waiting for a response from the PC.
• When you delete data from the DataMate (using DMM), the message stays on the display, until it gets a response from the PC

Yes. DMM for Windows lets you retrieve all the readings at once, and then and save them, one by one, as tab delimited files. This is quick and easy.

You can also “print” to a terminal program. Any terminal program (such as ‘hyperterm’ in Win95/98) can recieve ASCII data from the DataMate. Set the serial parameters on your terminal program to the same baud rate, no parity, 8 data bits, 1 stop bit. On the DataMate, go to Datasets and choose Print. You will be prompted for a baud rate, and defaults to 9600. On the DataMate, select the dataset and press enter. The data will be output through the serial port in ASCII format.

We use a dessicant called Sorb-it. The instructions on the side of the packet tell you to bake the packet at 118 degrees C (245 degrees F) for 16 hours.

The DataMate’s memory has been corrupted and most data cannot be retrieved. There are three ways that this might have occurred.

1. If you tried to delete datasets in the datamate’s memory, but accidently shut off the DataMate during the deletion process, memory will become corrupt. This is in the manual, but it is easy to forget.

2. There is a loose circuit board inside the DataMate. To check, you should open the DataMate to check that the circuit boards are firmly seated in their sockets. While you do that, you should disconnect the battery for a few minutes and then reconnect. This causes a full system reset. Be sure to ground yourself to prevent damage to the boards through static discharge.

3. One of the circuits in the DataMate has failed. After you perform the step above, switch on the DataMate. If the DataMate displays any system error, it must be returned for repair. If the DataMate does not display any errors, please try this: Use DMM to send datasets to the DataMate until the DataMate’s memory is full. Then disconnect from the PC. Now try deleting some datasets (using the DataMate keys) and adding a new dataset (just press the keys – the probe is not necessary). If there is failure again, the DataMate must be returned. If there is no failure, the DataMate may be OK, but please retrieve data regularly, just to be save.

Do you already have 40 installations? That’s the maximum number you can store in early DataMates. If you’re in the field and need to do a survey of a new installation, you can use another installation as a temporary holder for your data – just edit its parameters as required. Later, when you return to the office, you can place the survey under a proper installation

Yes. Humidity greater than 60% can cause problems, particularly when the DataMate undergoes temperature changes, such as being taken from a warm office to cold outdoors or from hot outdoors to air-conditioned office. If possible, store the DataMate in a cool, dry place in winter and in a warm, dry place in summer. 

Yes, there are certain reading values that are good indicators of problems:

Reading of 12000 in either axis: This indicates a sensor problem.

Reading of ±6000 to 8000: This indicates a power line problem if it appears both axes. The problem is probably in the cable or a connector.

Reading of +730 or 740 (English) or +1280 or 1290 (Metric): This indicates an input line problem on DataMates with firmware version 1997 or earlier. This is the same reading that appears if no probe is connected. The problem is probably in the cable or a connector.

Reading of +1786 or 1787 (English) or +3125 or 3126 (Metric): This indicates an input line problem on DataMates with firmware 2005 or later. This is the same reading that appears if no probe is connected. The problem is probably in the cable or a connector.

Reading of 60 or some other low number: If you see a low number that stays constant in one axis, the problem is mostly likely in the probe. The accelerometer for that axis is not working and the op amp is trying to compensate, resulting in a constant value.

There are two ways this can happen. (1) You are accidentally telling the DataMate that you have a metric (or English) system, or (2) the installation information in the DataMate is incorrect.

Case 1: When you start a survey using the DataMate, you choose an installation and then you must step through the installation parameters by pressing the Enter key. If you press the down arrow by mistake, you’ll change the value of that parameter. For example, if you press the down arrow at the Units prompt, you’ll change the value from English to metric or vice versa. It seems logical that you could press the down arrow to scroll through the readings, but you can’t. Always press the Enter key to step through the parameters.

Case 2: You should check that installation information in the DataMate is correct. Switch on the DataMate. Choose Read to display the Read menu. Then choose Installations. Scroll through the list of installations and choose the one that is causing problems. Then step through the installation parameters until you see Units. Set this to English or metric, depending on the type of probe that you have. Press Enter to see the next parameter, Ins Constant. Set this to 20000 for English probes or 25000 to metric probes. Also, check your DMM database to see that probe type and instrument constant are set properly for that installation.

Fixing Incorrectly Recorded Data: If you recorded an English probe with a metric setting in the DataMate, or you recorded a metric probe with an English setting in the DataMate, your data values are not correct. There are three solutions.

1. In DMM, edit each value in the affected survey.

2. In DMM, edit the

Apply a sensitivity correction in DigiPro.

3. Change the Probe Constant for that You can edit each value in the survey and keep , you can or you can change the instrument constant for each affected survey so that computed deviations and displacements will be correct. Here are instructions:

1. Open the project database, choose the appropriate installation.
2. Choose the appropriate survey and click the Edit Add button.
3. Change the value in the “probe constant” field as follows:

There are two ways this can happen. (1) You are accidentally telling the DataMate that you have a metric (or English) system, or (2) the installation information in the DataMate is incorrect.

Case 1: When you start a survey using the DataMate, you choose an installation and then you must step through the installation parameters by pressing the Enter key. If you press the down arrow by mistake, you’ll change the value of that parameter. It seems logical that you could press the down arrow to scroll through the readings, but you can’t. Always press the Enter key to step through the parameters.

Case 2: You should check that installation information in the DataMate is correct. Switch on the DataMate. Choose Read to display the Read menu. Then choose Installations. Scroll through the list of installations and choose the one that is causing problems. Then step through the installation parameters until you see Units. Set this to English or metric, depending on the type of probe that you have. Press Enter to see the next parameter, Ins Constant. Set this to 20000 for English probes or 25000 to metric probes. Also, check your DMM database to see that probe type and instrument constant are set properly for that installation.

Moisture in the connectors is the most common cause. There are three connectors that could be affected: the connectors on the control cable and the connector on the probe. Use an ohmmeter set to the 2 Megaohm range to check. Check cable connectors when the cable is not connected to the probe or the DataMate. Check the resistance from pin to pin and pin to connector body. In each case, the ohmmeter should read overrange (infinite resistance). If you see another reading, there is a problem. A reading cause by moisture usually drifts (does not remain steady). Continuity checks for the conductors should read about 1 ohm per 100 feet of cable. Check the pin to probe body resistance (not pin to pin). The roll pins (pins that go through the body to hold the springs) make a good connection to the body. Again, the reading should be overrange. If you find a problem in the cable connector that plugs into the DataMate, you may be able to disassemble and dry the connector by yourself. See this technote for directions. However, if you find moisture in the cable connector that attaches to the probe or in the connector built into the probe itself, you must send them to the factory for servicing. Send both items. See instructions for returning equipment to Slope Indicator.

the DataMate records both A and B axes with only two passes through the casing: the A0 and A180 pass. The B axis is less accurate because the wheels can move from side to side in the A grooves, and this affects the tilt of the sensor in the B axis. Slope Indicator’s casing has very narrow grooves, so this is not usually a problem. However, if you are using casing that has wider grooves, the probe can wander in the B axis and give less accurate readings. In that case, the highest accuracy is obtained by orienting the probe so that the wheels travel in the B axis. (Thus you use the A-axis accelerometer to record B axis readings).

The DataMate offers a “Uniaxial” routine that lets you record one direction at a time: A0, A180, B0, and B180. When you step through the parameters of the borehole before recording a survey, change Type from Digitilt to “Spiral.” This tells the DataMate to perform a uniaxial survey. Keep your instrument constant, depths, and intervals the same as usual. The DataMate will then prompt for the A0 pass, continue with the A180 pass, and continue with the B0 and B180 grooves.

When you retrieve the data with DMM, you have to make one change. In the dataset header of DOS DMM, change the value of “Spiral?” to N or False. In the Windows DMM, change the value of Probe Type from Spiral to Digitilt.

There are two possibilities.

1. There may be a partial vacuum in the box due to air shipment. The vacuum is sucking on the keypad and causes the “key down” error message. In this case, unscrew the two screws at the bottom of the box and wiggle the box a bit. This should allow air to flow into the box and release the keypad.
2. The keypad may be too large for the panel. In 2004, we received a batch of keypads that were slightly too large. They fit the panel well enough during assembly, but later expanded. The result was this same “key down” error. In this case, please contact your distributor. He may be able to replace the keypad or will send the box to us for repair.

The answer involves both the inclinometer probe and the orientation of the inclinometer casing. 1. The inclinometer probe contains two accelerometers. One accelerometer senses tilt in the plane of the wheels. The other accelerometer senses tilt in a plane rotated 90 degrees to the wheels. The drawing at right is a top view of the probe. If the bottom of the probe is held in a fixed position, moving the top of the probe in the direction of the arrows results in positive and negative readings. 2. Inclinometer casing has grooves that control the orientation of the inclinometer probe. Usually one set of grooves is aligned with the expected direction of movement (For slopes, this is usually downhill. For excavations, this is usually toward the area being excavated). The probe travels in this set of grooves. If the probe is inserted so that the upper wheel points to the expected direction of movement, then A0 pass through the casing will show positive tilt if there is actually tilt in that direction. 3. On a graph, positive movment is shown on the right side of the graph, assuming that casing grooves are aligned with the direction of movement and that the probe was inserted with the upper wheels pointing in the downhill direction for the first pass.

It is not a good idea to use an English probe with a metric cable (or vice versa). You will introduce errors and lots of complications. Here’s a suggestion of how you can switch over those installations from English to metric:

1. Rent an English Digitilt system and take a final survey of the inclinometer installations with the English system.
2. On the same day that you take the final English readings, take two or three surveys of the same installations with your metric system.
3. Reduce the English data, evaluate the displacements and file all the readings from the past. This closes the book on the English unit data.
4. From now on, use only your metric system. Choose one of your metric datasets and use it as the initial. If you must report information in English units, use DigiPro for Windows to generate English unit graphs and data from your metric readings.

At one time, we recommended regular recalibrations. Now we recommend recalibrations only for the following three conditions below.

Condition l: Your probe requires repair. After we repair your probe, we must recalibrate it.

Condition 2: You need the probe certified for your company’s quality program. In this case, we may not actually open the probe to make adjustments. First, we put the probe on our tilt table to generate a calibration form. Then, if the probe is found to be within tolerances, we print out the calibration form. However, if the probe is found to be out of tolerance, we open it, make the necessary adjustments, and then run the calibration test again.

Condition 3: If you follow ASTM Standard D7299 (http://www.astm.org/Standards/D7299.htm) and readings in the check stand or in an inclinometer installed on stable ground show drifting or unusual readings.

Summary: If your readings and graphs are consistent, and there is no obvious need for repair, we recommend that you continue using the probe as is. Recalibration is unlikely to significantly improve the performance of a probe that is already working well.

Note that the probe is a special case. Other instruments, particularly readouts, can benefit from annual recalibrations.

These values are used for manufacturing quality checks. They assure us that the accelerometers are aligned properly and working properly. The values have no practical application for end users.

Slope Indicator’s manuals recommend that users lower the probe to the bottom of the borehole and wait 5 to 10 minutes before starting the survey. This “warm-up” period allows (1) the electronics of the probe to warm up and stabilize and (2) the mechanicals of the probe (wheels and housing) to match the temperature of the water in the casing. What happens if the user omits the warm-up period?

Readings taken during the first 5 or 10 minutes of the survey may contain an offset that later readings do not. When readings are processed, the offset error may look like movement at the bottom of the borehole. How severe are the errors? The offset error will be smallest when a warm probe (25 to 30°) is lowered into 12°C water, which is the typical groundwater temperature in moderate climates. In such conditions, a shorter, 3 to 5 minute warm-up period will provide good results. The offset error will be greatest when the probe is cold. For this reason, be sure to allow at least 10 minutes warmup time for cold probes. Note that the readout’s Ready signal does not monitor the warm-up period and should not be used for that purpose.

This is a problem that is exhibited by all inclinometer probes. The wheels of the probe, which travel in the ‘A’ grooves, are slightly narrower than the grooves in the casing. That means the wheels have some freedom to move from side to side within the grooves. The A axis of the probe is in-line with the wheels, so it is not affected by side to side movement of the wheels. Also, the spring loading of the wheels prevents any ‘wobbling’ in the A axis. The B axis of the probe is directly affected by side to side movements, which appear as small changes in inclination. Why don’t we make the wheels fit the grooves perfectly? If the wheels fit perfectly, the probe would be forced out of the grooves when the casing deformed, and then repeatability would be very bad. Slope Indicator is working on another solution to this problem, which we will announce in a few months.

Calculate the difference between the inside diameter of the casing and the outside diameter of the probe. For example, 85 mm casing has a 73 mm inside diameter and the probe body has an outside diameter of 24.5 mm, so the maximum allowed deformation would be 48.5 mm.

Complex Answer: This answer assumes a constant radius curve and describes tracking limits in terms of reading units. 

 Probes are interchangeable when they leave the factory – they can be interchanged and still meet the system accuracy spec that we list on our brochures ( .025 feet per 100 feet). However, soon after being put into service, each probe begins to acquire its own characteristics – a bump here, a knock there, a severe curve in the casing, etc. After a while, correcting the output of one probe to match that of another probe becomes quite difficult and would involve a lot of record keeping. Control cables can also acquire their own characteristics, depending on how they are used. For this reason, we recommend using the same probe and same cable for any particular installation. Also see the question below.

If you are using the same probe and cable as the previous consultant, you should have no problem using the original baseline data. However, if you are using a different probe (or a new probe), several variables come into play. The most important of these are the profile of the casing as installed and the condition of the two probes and cable.

If the casing was installed vertical and straight, differences between probes will be minimized. Vertical casing shows less than 3 degrees of cumulative deviation from the bottom to the top of the casing. You can check this by making a cumulative deviation plot. and calculating the overall degree of tilt. If you find more than three degrees of tilt in either axis, there is a good chance that you’ll see a difference in the readings of the two probes. Tilt in the B axis will affect A readings, and tilt in the A axis will affect B readings.

Casing is considered straight if it does not snake from side to side within the borehole. You can check this with an incremental deviation plot. In the ideal plot, lines would be vertical. Non-vertical lines indicate waviness in the casing. In “wavy” casing, depth control becomes an issue, and slight differences between your old control cable and your new control cable can make difference in readings.

The easiest way to check compatibility is to take about three surveys with your own probe and compare them to the latest survey taken with the previous probe. (If you have a completely new probe, run it up and down in the casing about five times to break it in). If the resulting cumulative displacement plots overlay the latest survey from the old system, you’re in luck. But if you see significant differences, then you have two choices:

1. Complete the old series of surveys by printing a final summary of cumulative displacement and time vs displacement. Also print a comparison of the final survey with the old system to the initial surveys take with the new system. Then archive that data. Use one of the three surveys you obtained with the new system to start a new series. This is generally the most satisfactory method in the long term. Here’s the logic behind it: you know the magnitude and rate of movements you were detecting with the old system. If movements are increasing, you will catch them with the new series. If the ground has stabilized, the new series will tell you that, too.

2. Your second choice is to correct every survey taken with the new system to make it compatible with the old system. This is a lot of work, for very little reward. For this reason, we recommend the choice above.

 A jump in checksums does not necessarily indicate a problem with data or the probe. However, if your probe becomes less consistent – i.e. you start seeing frequent jumps in checksums, it may be time to have your proble checked. The SD of checksums that you report indicates that there is no problem now.

Checksums of 10 or 20 are actually within the spec of the probe as it leaves the factory. So long as the checksums are consistent, there will be no problem with the data. The main component of a checksum is the bias of the probe. (A check sum is 2 x the bias of the probe). The 0 and 180 surveys effectively cancel the bias, so data are not affected. However, there are two conditions that you should watch for:

(1) Check for large changes in the mean checksum from survey to survey. Use DigiPro’s checksum graph: If plots are close to each other, there is no error. If plots are separated widely, there may be bias-shift errors.

(2) Check for drifting checksums – checksums growing consistently larger or smaller from bottom to top. Use DigiPro’s checksum plot again. Each plot should be vertical. If the plot tilts to the right or left, there is drift. This is probably an indication that an electronics board is bad.

This is a very common question, so we have prepared a tech note on inclinometer accuracy. Hopefully, it will answer your question fully.

 Improper coiling of any electrical cable twists the conductors inside the cable and will eventually cause reliability problems. Cable reels are one solution to this problem, but are typically used only with longer lengths of cable. With shorter lengths of cables, it is probably easiest to coil the cable by hand, either in figure-8s or in over-under loops. You can find a drawing of this in our inclinometer probe manual. Some DOTs report that they use two traffic cones to guide their figure-8 coils. Other people use a large laundry basket to hold their over-under loops. Still others have reported mounting garden hose holders on a backpack, one at the top and one at the bottom, and then making figure-8 loops. With longer lengths of cable, cable reels become more practical. There are two types of cable reels: storage reels and slip-ring reels. Storage reels are simply a place to store the cable. To use the cable, you must unreel it first. Some people use garden hose reels for this purpose. Note that any reel should have a hub diameter of about 12 inches (300 mm) to avoid small bends in the cable. Storage reels can be heavy, but then, so is the cable. Slip-ring reels provide an electrical connector, so that you have full operation of the cable while it is on the reel. Slip-ring reels tend to be expensive and heavy. Slope Indicator’s slip-ring reel weighs 37 pounds (16.5 kg). Thus is it not very portable. Mines and other sites with very deep inclinometer installations sometimes use motorized reels. These are even larger, heavier, and more expensive. They also have automation features, such as controlling the depth of the probe.

Yes, but this is not a simple task, and it can cause a shift in the calibration of the probe. Normally we recommend that this repair be performed at the factory, since the probe can be recalibrated after the repair. The repair requires kit number 50302555, which contains a wheel yoke with wheels, two springs, and four roll pins, so you normally need two kits per probe. If you are interested in replacing the wheels yourself, download these instructions to learn more.

ASTM now has a practice that lists the necessary equipment and method for verifying the calibration of your probe. However, in many cases, your data and graphs can go a long way toward satisfying your verification needs:

1. The bottom 10 feet of your casing should be installed in stable ground. This way, you are assured of a stable reference. (To be more exact, we recommend that you install 5-reading intervals of casing in the stable ground, thus with metric casing, this would be 2.5 meters.)
2. Since the bottom of the casing is stable, your surveys should show no movement at all within that ten feet. Any movement that you see is error. Thus you have an in-situ test stand.
3. With this in-situ test stand, you don’t need to perform any explicit tests. The information you need to check your probe is embedded in your readings.
4. This in-situ method of checking the probe is better than the test stand method for several reasons: First, the installed casing is more stable than any test stand on the surface. Second, the information is embedded in each inclinometer survey, so it won’t get lost. Third, the embedded information shows the condition of the probe at the exact time of the survey.

This information is provided for those who have already contacted the factory and decided to do a repair themselves. Wire colors vary according to the age of your cable, so you’ll have to use an ohmmeter to determine which wire you have. Note that this information is for making repairs to solder joints within the Lemo connector, which is on the indicator end of the control cable. Please do not attempt to make repairs to the connector on the probe end of the cable. It is extremely difficult to reassemble this connector properly.

Notes

• It is not really practical to try to match the strength of the grout to the strength of the soil, since the properties of grout and soil are so different. The cement-water ratio controls the strength of the grout. To decrease the strength of the grout, add more water.
• Drillers are accustomed to mixing water and bentonite first, but this will not allow you to control the water-cement ratio. Mix water and cement first. Then add bentonite. There is no particular amount of bentonite that you must add. The thickness of the grout varies with water, temperature, and agitation, so the amount of bentonite required will vary.
• The quantity of the third ingredient to be added must be adjusted to obtain a suitable consistency. A watery mix is NOT acceptable. A mix that is too thick cannot be pumped. The Marsh funnel number of the liquid grout should be about 55 seconds +/- a few seconds.
• If you mix cement and water first, the amount of bentonite has to be adjusted. The amount is rarely ever equal to exactly 25 lbs. The final quantity also varies with the type of bentonite used, the method of mixing and the pH of the water.
• If you mix bentonite and water first, the mix usually gets so thick with one bag of cement that it cannot be pumped. There is also a high risk of a flash-set. The cement content must usually be lowered. That results in a higher w/c ratio, lower strength and probably a higher permeability.
• If the mix is left too watery, not only do you get shrinkage, but segregation occurs: cement on the bottom, then bentonite and water on top (bleed). This is not acceptable.

• Suspend a steel pipe or drill rods inside the casing. For the best results, suspend the pipe just an inch or so off the bottom cap of the casing.This ensures that the steel pipe remains straight and avoids resting the full weight of the pipe on the bottom cap. As the casing rises to meet the pipe, the down force of the pipe is activated to keep the casing in place. The main drawback to this method is that you must use the drill rig to suspend the pipe or you must return with the drill rig to retrieve the pipe. A variation is to rest the pipe on the bottom cap, which you must reinforce.
• Pre-install an anchor at the bottom of the casing. Simple prong anchors or packer types have been used. Slope Indicator has produced several prototypes of such anchors. Different soils may require different types of anchor.
  Pre-attach a weight to the bottom of the casing. This method requires a weight, a safety line to prevent casing from sinking, a borehole drilled deeper to accommodate the weight, and calculation of the uplift force. It is best used in shallow boreholes.
• Grout the borehole in stages. The uplift force of grout varies with the height of the grout column. If the column is short, the uplift force is low and the casing can be held in place by its own weight or with very little down-force applied from the top. When the grout sets, the bottom cap is isolated from the column of grout and there is no surface for the uplift force to act on. No more than two or three meters to 3 m need to be grouted in the first stage. If the normal bentonite/cement grout is used it needs to set for at least 12 hours before second-stage grouting. Avoid use of a quick-set grout, since the heat of hydration could melt and deform the plastic. The two stages can be placed via an outside tremie pipe. Alternatively the first stage can be placed before lowering the casing, provided that all is done efficiently so that there is no chance of the grout setting prematurely. If grout valve method is used, first stage grouting can be done through the valve, and then the valve is abandoned. An outside tremie pipe for the second stage is lowered with the casing, with its bottom at the level planned for the top of the first stage. After first stage grouting, the excess is flushed out via the tremie pipe, and then this is raised until the first stage has set.
• Fill the casing with drilling fluid that is heavier than the grout. This is a sure and easy method, but requires disposal of the drilling fluid.

Unfortunately, the easiest way to keep the casing in place – holding the casing down from the top – is also the worst way. The uplift force acts on the bottom of the casing, so if the casing is held in place from the top, the casing goes into compression. When the casing goes into compression, it tends to snake from side to side in the borehole. This problem is particularly severe in large diameter boreholes and in deep installations, where the uplift force is largest and where portions of the borehole may be enlarged. Snaked casing increases the potential for:

• Kinked or Separated Casing: The combination of compressive force and eccentric loading (due to snaking in enlarged diameter boreholes) can produce strong bending moments in the casing. In some severe cases, this bending moment has caused snap-together joints to fail where the glue-and-rivet joints do not.
• Depth Errors: In snaked casing, slight changes or errors in the positioning of the probe will produce reading errors. The larger the curvature, the larger the error. For example, if the change of inclination between adjacent reading increments is two degrees, and the probe is positioned 25 mm from the correct depth, the resulting error in displacement would be 1 mm.

Erik Mikkelsen says:

I have heard this concern voiced from time to time, but the evidence from measurements in slopes and landslides suggest that it should not be a big concern, particularly in soft (loose) soil.

In soft soils, shear displacements are more distributed than in harder soils. For example, the shear zone in a basalt landslide complex was measured to be 15 inches thick using special inclinometer procedures. On the south Oregon coast (Arizona Inn landslide) in mélange, the shear zone is on the order of 2 to 3 feet thick after a major rupture and repair work. Measurements at the toe of an embankment in soft silts and clays next to the Puyallup River in Tacoma indicated a shear zone of 4 to 6 feet.

Based on the experience above, I think that within the measurable range of the inclinometer system, the stiffness of the inclinometer casing will not appreciably redistribute displacements. A significant rupture occurs most likely on a plane or a thinner zone, but that is the beyond the range that the inclinometer can measure. (The casing simply closes and does not allow passage of the probe).

Inclinometer casing made from ABS is relatively weak compared to the ground and is quite ductile. It does not normally crack due to excessive deformation, it cold flows. It would be difficult to come up with a “softer” material that would meet production, installation and tracking requirements.

There are two other significant factors in soft soils. Drilling of the borehole can alter the conditions around the installation. Loose soil can densify and cave, changing the natural conditions.  The stiffness of the backfill also has an effect, since it typically occupies 75% of the borehole cross-sectional area.  Grout stiffness is probably a greater issue than the ABS casing stiffness. Not much information is available on design and characteristics of soft cement-bentonite grout as far as I know. In soft soil the “instrument disturbance factor” can be significant.

Finally, even if there is some redistribution of displacements due to grout and casing stiffness and borehole disturbance, the inclinometer will measure the correct total amount, but over a longer interval of the borehole.  Also, the true profile of the casing in the shear zone cannot be defined by ordinary methods. Special techniques using 3-inch reading intervals and special calculation methods must be used.

To prevent the water from freezing we recommend filling the casing with a water + propylene glycol solution. Propylene glycol is a non-toxic antifreeze fluid. Although this solution should be harmless, always wash off the probe and cable after use.

Here is a table showing the freezing point for various solutions. The table is provided by engineeringtoolbox.com.

Casing is designed to deform with movement of the adjacent ground or structure. The useful life of the casing ends when casing curvature forces the inclinometer probe out of the grooves in the casing. Continued movement of the ground pinches or shears the casing, and eventually prevents passage of the inclinometer probe. Large diameter casing (85 mm, 3.34 inch) is suitable for landslides and long term monitoring. It is also appropriate for monitoring multiple shear zones or very narrow shear zones. Large diameter casing is required when the horizontal probe is used. Medium diameter casing (70 mm, 2.75 inch) is suitable for construction projects. It can also be used for slope stability monitoring when only a moderate degree of deformation is expected. Small diameter casing (48 mm, 1.9 inch) is suitable for applications where small deformations are distributed over broad zones. It is generally not installed in soils. 

 It is important to have some cement in the mixture for dimensional stability. Bentonite alone will never set and its volume varies with moisture levels.

The water filled casing is lighter than grout backfill, so the uplift force acting on the bottom cap of the casing tends to push the casing out of the borehole.

We refer to this as an orientation error, however, it is probably not a problem at all. In fact, you may find it to be an advantage. At 10 degrees, your A axis readings will capture 98.4% of the magnitude of the total movement, and movement seen in the B axis can be used to confirm that the A movement is real. 

This drawing shows a right triangle with sides A, B, and R, which represent the A-axis value, the B-axis value, and the resultant R, which represents the actual magnitude and direction of movement. The angle is the angle of misalignment (10 degrees in this drawing). The ratio between A and R is equal to the cosine of the angle. The cosine function works slowly, so even at 25 degrees of misalignment, the A-axis value contains 90% of R. The ratio between B and R is equal to the sine of the angle. The sine function works more rapidly. With a 10 degree misalignment of the A-axis, as shown in the drawing, the B-axis value will contain about 17% of the resultant. Thus any displacements seen in A should also be seen in B

The heavy-gauge PVC pipe could work if it survives the hoisting and insertion process. I don’t think the softer modulus of the PVC is an issue at all. The PVC pipe will be totally encased in the reinforced concrete. Both the PVC pipe and a grouted-in ABS inclinometer pipe inside will move as the wall moves, they will be slaved to the concrete as weak members.

The main issue is how well the PVC is attached to the cage to survive bending during hoisting and the uplift force acting at the bottom cap of the pipe in the fluid concrete. (Please calculate the forces to find out what you are dealing with, tying wire may not be sufficient.)

A steel pipe would be stronger and heavier in this situation and would be preferred by most contractors. Again, I don’t think the lateral stiffness of the steel pipe is an issue in reflecting correct displacements. Should it act as a stiff member, the displacements would be distributed over a slightly greater interval of depth, usually insignificant since the vertical instrument resolution is 0.5 meter.

This is an easier installation if the wall concrete is tremied in after the pipe is inserted with the steel cage and the pipe is filled of bentonite slurry or water.

One technique is to weld a pipe to the sheet pile. Plug the end of the pipe and drive it in with the pile. Drill out the plug, boring 10 or 20 feet into the soil below the bottom of the wall. Then install your inclinometer casing inside the pipe. Grout it in. With the bottom of the casing in stable ground, you will be able to detect movement at the base of the wall in addition to monitoring the profile of the wall (the pipe is unlikely to add significant strength to the wall).

 The hole should be drilled as close to vertical as possible. Verticality is limited by the capabilities of your drill rig, the crew, and the local geology. However, one to two degrees from vertical are typical values used in specifications. Accuracy specifications from Slope Indicator assume that the inclination is less than 3 degrees.

Vertical boreholes eliminate one type of systematic error, called rotation error, that can occur if inclinometer probes are interchanged or if the mechanical alignment of a single probe changes over time AND the borehole has significant tilt.

Yes. Ordinarily, the torque (twist) strength of the QC coupling is satisfactory without any supplemental action. However, if the drillers suspect that they will have problems removing the drill casing or if the borehole is very deep, you could consider placing a steel band around the casing, covering the white button. This low-profile band provides much additional torque strength and is quick and easy to install.

Deep boreholes are more than 50 meters (150 ft) deep. We cannot provide exact instructions, since there are different variables at each site: different geology, different drill equipment, and different expertise of the installers. However, we can suggest some guidelines:

Be Prepared

The engineer at the job site should be aware that deep installations require extra calculations and planning. For example: the engineer must calculate all the pressures and forces that will act against a successful installation and plan for stage grouting.

Type of Casing

When possible, use casing with glue-and-rivet couplings. Slope Indicator’s Standard casing is the best for this application because it has flush joints and is easy to seal. Slope Indicator’s QC casing, with its snap-together joints, can also be used, but it does not have the torsion strength of Standard casing. The torsion strength of the QC joints can be improved with straps, as shown in the photo above. Alternatively, pop rivets in the joint can add torsion strength, but the rivets must be sealed carefully to prevent entry of grout. Note that experienced installers have used un-reinforced QC casing sucessfully to depths of 230 m (700 ft). However, we recommend the reinforcement for most installers.

Grouting

A bentonite-cement grout is the preferred material for backfilling boreholes of any depth. It is particularly important for deep boreholes, since they may otherwise provide an unwanted connection of aquifers at different elevations. Grouting is done from the bottom to the top of the casing. In deep holes, the pressure of the grout can cause even water-filled casing to collapse.

Stage grouting is necessary to limit these pressures. The first stage is normally limited to about 30m or 100 feet. A tremie pipe – or plastic tubing – should be installed with the casing. In some cases, the first stage can be grouted via a grout valve installed in the bottom of the casing. In this case, the grout pipe is lowered through the casing to mate with the valve at the bottom. For deep depths, however, an external pipe is best. It can be left in place or withdrawn.

Before the grouting operation starts, it is a good idea to check the casing with a dummy probe to make sure that none of the joints have failed or pulled apart during installation. If everything is OK, proceed with the grouting.

Use a bentonite-cement grout mix. Adjust the strength of the grout by mixing cement and water first. This allows you to control the strength of the grout. Bentonite is then added as required. Always collect a sample of the grout in a paper cup. You can check it in 24 hours and also do lab tests, etc.

Other Standard Practices

Establish the proper alignment of the casing grooves. One set of grooves should be parallel with the expected direction of movement. (downhill or toward the excavation, in most cases).

Maintain this alignment, checking it each time another length of casing is added. Also check that the joint is made properly and not forced together incorrectly. The company name & casing size are printed along the length of the casing over one of the groves. So, by watching the printing, the position of the internal groves is known.

Avoid realigning the casing orientation after the casing has been placed in the borehole. With deep holes, twisting at the top is unlikely to affect the bottom, so the casing will become spiraled rather than realigned.

In water-filled holes, it will be necessary to fill the casing with water to allow it to be pushed downhole. In dry holes, avoid filling with water because the pressure can blow out the joints from inside. In holes that are partially filled with water, start adding water to the casing when the bottom of the casing reaches the water.

It is not possible to predict the yield of the mix design because we don’t recommend a fixed quantity of bentonite. The quantity of bentonite used in the mix will depend on the pH and mineral content of the water used, the moisture content of the cement and bentonite, and the amount and type of byproduct within the locally sourced bentonite powder.

It is possible to calculate a gross estimate of the yield using 3.15 as the specific gravity of cement and 2.35 as the specific gravity of bentonite, but it must be considered a gross estimate as the expansion rate of the bentonite will not be the 10X volume change when it is mixed with fresh water. It will be a variable due to the redox reaction of the cement and water changing the properties of the water. This also increases the difficulty in calculating the yield ahead of time.

The best method of determining the yield is to mix a test batch using the actual materials that will be used on the project, although it should be noted that there will still be some differences between the test and the production grout, as the moisture content of the cement and bentonite will likely be different on test day versus on production day.

You will need an Android phone or tablet, an OTG (On The Go) cable, the GTecLink app (which can be downloaded from the Google Play Store or via this link) and at least one 3.6V C-size lithium battery.

You may need to change the security settings of your Android device to allow third party apps to be installed. This allows you to install apps directly from the device memory. You will also need an OTG cable to connect from your device to the node. Depending on your Android device, you will either need a MicroUSB to MiniUSB cable (DGSI p/n 52616704) or a USB-C to MiniUSB cable (DGSI p/n 52616705).

Once the app is installed on your device, connecting the device to the node should automatically open the app. From there, go to the Setup Wizard and it will walk you through setting up the node. Please note that if you are using a Gateway, it should be installed and operational prior to setting up the nodes so that a proper radio signal test can be performed between the node and the Gateway.

You can watch an instructional video on setting up the nodes here https://youtu.be/3CwGxrEx1zg

Try this quick method first. It should should work with most systems.

1. Download and install the most recent software: Check our downloads page for DigiPro2.
2. Download and run the USB Driver Installer: CDM212364_Setup.zip.
3. Connect the DataMate II and switch on. Windows should recognize the device.
4. If you have problems, please look at the DataMate Communcations FAQ.

Multi-Part SetupThis multipart setup should not be necessary for most systems. .Part 1: Installing the Digitilt DataMate USB Driver

Grout backfill has a higher density than water-filled casing. During installation, when the grout is still a fluid, it exerts an uplift force on the bottom cap of the casing. This uplift force is greater than the down force exerted by water-filled casing. The net uplift can be calculated as the density of grout minus the density of water filled casing x depth of casing x area of bottom cap. Lateral forces do not contribute to uplift.

The density of water-filled casing is about 62.4 pounds per cubic foot or 1000 kg per cubic meter. The density of ABS casing and the density of water are nearly the same. The density of bentonite-cement grout is about 80 pounds per cubic foot or 1280 kg per cubic meter. The area of the bottom cap of 2.75″ (70mm) inclinometer casing is 0.0412 square feet or 3.8485E-3 square meters. Thus if the bottom cap is 100 feet deep, the uplift pressure on the 2.75 inch bottom cap will be about 72.5 pounds or 32.3 kg