Inclinometers

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.