VWP Indicator Q&A

Question: I'm repairing a jumper cable for the VWP Indicator. What are the pinouts?

Answer:

1 GND
2 Hz
3 Hz
4 No Connection
5 Rtd
6 Rtd

Question: We have been using the "microstrainVS" setting rather than "microstrainVW" to read VW spotweldable strain gauges. How can I convert these VS readings to the correct microstrainVW readings?

Answer: The data can be converted without too much difficulty. The main problem is that the VS readings used a 2nd order equation, consequently you will need to solve a quadratic equation using the following formula:

Hz = SQRT(711.09 * VS + 6783) - 82.4     (where VS is the microstrainVS reading)

Then, to convert the result to the correct microstrainVW reading, use the formula below:

uStrain = (Hz^2 / 1320) - 2030.1

For your convenience, we've made an Excel worksheet that provides these equations. The file is called VS2VWmicrostrain. You'll need an UnZip utility to access the file.

Question: I've been recording piezometer readings using the microstrain setting. How can I convert microstrain to Hz?

Answer: We've made an Excel worksheet for this. The file is called strain-to-hz-xls.zip. You'll need an UnZip utility to access the file.