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3. Confirm that the RecordNo field of the VW_Data table is incrementing at the proper
measurement interval, and that the measurement data (frequency, temperature) is correct.
The Time Stamp field should also update as each measurement is made.
4. Use the Troubleshoot tab to see detailed information about the vibrating-wire sensor
measurements made by the CRVW3. Manually trigger a measurement test and see
diagnostic results within a few seconds. Select your Channel and click Options to set a test
sweep excitation and frequency filtering window, and the excitation voltage level. Click Poll
to initiate the test. Results will be displayed on the screen within a few seconds. For more
information, see
Confirm CRVW3 sensor measurements
5. View the frequency domain response of the vibrating-wire sensor in the Spectrum window.
Peaks in the spectrum indicate the main frequencies at which the sensor wire vibrated
during the measurement. The strength of the peaks is shown in the millivolt (mV) scale.
Drag a rectangle on the viewing area to zoom in, then click Undo Zoom to return to the
initial scale.
6. Use the Time Series window to see the motion of the sensor wire in millivolts (mV) during
the measurement period as given by the changing magnetic field sensed by the coil
circuitry. Drag a rectangle on the viewing area to zoom in, then click Undo Zoom to return
to the initial scale.
7. The main frequency reading is given in the Peak Frequency box in units of Hertz (Hz).
8. The following diagnostic readings help assess the quality of the reading:
l
Signal-to-noise ratio: Amplitude (mV) of the strongest frequency peak in the
spectrum divided by the amplitude (mV) of the second strongest frequency peak.
l
Decay ratio: Amplitude (mV) of the time-series motion of the wire at the beginning of
the measurement divided by the amplitude (mV) of the wire motion at the end of the
measurement. This can also be approximated by a study of the results in the Time
Series window.
l
Peak amplitude: Amplitude (mV) of the strongest frequency peak in the spectrum.
l
Noise frequency: Frequency (Hz) of the second strongest frequency peak in the
spectrum.
CRVW3 3-Channel Vibrating-Wire Data Logger
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