VW Analyzer

VW Analyzer

Overview

Durham Geo Slope Indicator's VW Analyzer is the most innovative vibrating-wire field reader available.

The VW Analyzer is field ready to quickly measure your sensor, save your data, and communicate the results with custom PDF reports and spreadsheet output. VW Analyzer measurements are geo-located with an integrated GPS, allowing the device to verify locations and direct you to your sensors. The VW Analyzer uses spectral-analysis technology (VSPECT™) to provide the best vibrating-wire measurement possible while filtering out environmental and electrical noise. The large color display offers you an easy-to-view graphical presentation of the data.

Benefits and Features

  • Create custom PDF reports
  • Measurement confidence with graphical display and VSPECT technology
  • Full-color screen and easy-to-use menus
  • Integrated GPS records sensor location
  • Able to read any vibrating-wire sensor
  • Sensor library containing common vibrating-wire sensors
  • Quick transfer of PDF and CSV files with a USB connection
VW Analyzer

Detailed Description

The Vibrating-Wire Analyzer (VWA) uses patented VSPECT™ technology for the most reliable vibrating-wire measurements available. The VWA converts measurements to engineering units, generates a printable PDF report, and saves a CSV summary file. The graphical display allows confirmation of sensor output and operation. VSPECT™ technology eliminates disruptive noise interference and provides sensor diagnostics for the best measurement possible. VSPECT™ noise immunity allows gages that are otherwise unreadable to be evaluated with confidence.

A Project File maintains Site/Sensor information for 40 unique sites with 22 sensors per site. Site/Sensor locations are geolocated, allowing the internal GPS to guide a user directly to a sensor location. Site/Sensor and user information can be created or edited on the device or with a computer using the free VwProjects software.

Note:  The VWA can be connected to a computer and is treated like an external memory device (flash memory drive) to transfer data.

What is a VSPECT measurement?

VSPECT provides the best vibrating-wire measurement available. A sensor frequency is easily identified while filtering out environmental and electrical noise that affects the quality of other vibrating-wire readers. VSPECT provides measurement diagnostics to understand sensor response, installation quality, and identify incorrect wiring or damaged sensors.

Output and Diagnostics

Sensor Frequency (Hz)

Basic measurement from a vibrating-wire sensor. The frequency can be converted into engineering units (for example, pressure, displacement) and is the largest measured amplitude signal within the frequency sweep.

Sensor Amplitude (mV RMS)
Diagnostic values describe the quality of the frequency measurement. Signal strength from the vibrating-wire sensor. Amplitude varies and is affected by the sensor type, excitation strength (adjustable), and sensor cable length.
Signal-to-Noise Ratio (unitless)

Diagnostic values describe the quality of the frequency measurement.

Sensor signal amplitude divided by the largest noise amplitude within the sweep frequency. A low signal-to-noise ratio indicates a weak sensor signal or a noisy environment.

Noise Frequency (Hz)

Diagnostic values describe the quality of the frequency measurement.

Largest amplitude noise signal within the frequency sweep.

Decay Ratio

Diagnostic values describe the quality of the frequency measurement.

Signal attenuation (how quickly the signal strength decreases).

Thermistor/RTD Resistance (Ω)

Resistance is a measured value.

Measurement used to calculate sensor temperature and correct for thermal effects. The VWA measures the vibrating-wire sensor temperature (when present); thermal and barometric corrections require post processing.

VW Analyzer Specifications

VW Analyzer Specifications
Memory
1,700 site/sensor measurements (most recent)
40 unique sites, 22 sensors per site
240 single measurements (most recent)
16,500 continuous measurements (most recent)
80 MB USB memory (PDF, CSV, VWA, and other files)
GPS ±5 m (16.4 ft) typical (±1 ms time sync)
Channel Count 1 channel (vibrating wire and thermistor reading)
Enclosure IP62
Battery Type/Life 5 AA (1.5 V), 20 hours continuous use
Operating Temperature 20° to +70°C
Compliance CE, RoHS
USB Mini B Direct connect to PC (Supplies power to retrieve data)
Warranty One year against defects in materials and workmanship
Dimensions 200 x 100 x 58 mm (7.9 x 3.9 x 2.3 in.)
Weight 0.34 kg (0.75 lb)
Measurements: Vibrating-Wire
Vibrating-Wire Frequency Range 300 to 6500 Hz
Resolution 0.001 Hz RMS
Accuracy ±0.005% of reading
Excitation 2 V, 5 V, 12 V (user-selectable)
Method VSPECT (Vibrating-Wire Spectral Analysis), U.S. Patent No. 7,779,690
Measurement Interval Range 1 s to 15 min (continuous reading mode only)
Speed 1 s (fastest)
Measurements: Thermistor
Resolution 0.01 Ω RMS
Accuracy ±0.15% of reading
Compatibility
The Vibrating-Wire Analyzer (VWA) can measure all vibrating-wire sensors including, but not limited to, strain gages, piezometers, pressure transducers, tiltmeters, crackmeters, and load cells. The VWA has an integrated sensor library that contains common sensors from common vibrating-wire manufacturers; use of the sensor library allows the VWA to output data using engineering units.