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Sensor Calibration Using DAQ

Hello,

I have an application that I need to create that will provide me with the sensitivity value for the accelerometer I'm using.  I found some calibration VI's within the sound and vibration toolkit that we have but I think I must be setting up something wrong as my output is no where near what it should be.

I am using a USB-9233 DAQ, with a calibrated sensor/magnet, and a calibrated shaker table.  I think my problem is in the units, but vibration isn't my thing...maybe someone can spot the problem?

Sensor is a CTC p/n: AC102-1A (100mv/g nominal sensitivity)
Shaker table is an IRD 421 shaker (documentation on this old thing is near impossible to find)
The shaker table has a dial to adjust 1-6 mils pk-pk, or 0-150 microns pk-pk.

The sensor will require excitation, but thats carried within the BNC of the 9233.

I attached a picture of my code, and the output.  Like I said though, since the scale is in mils pk-pk that I'm adjusting to on the shaker table, there has to be a conversion somewhere.  On the channel info input there is a place for EU, but I believe thats the sensor itself. (Thats where I put the 100 mv/g part)

Any help would be appreciated!


LV7.1, LV8.5, LV2014/15/16
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3 mils pk-pk displacement should be converted to g rms acceleration when entering the calibration value to the calibration VI:
 
3 mils pk-pk * (1 pk-pk / 2sqrt(2) rms) * (0.0000254 m / mil) * (1 g / 9.81 m/s^2) * (2*pi*60 rad/s)^2 = 0.39 g rms
 
 
If you input 0.39 g rms for the calibration value instead of 3 mils pk-pk, you get the following computation for calbrated sensor sensitivity:
 
13.01 * (3 / 0.39) = 100.06 mV / g
 
The sensor sensitivity in channel info is not used as part of the computation, but it is measured and returned in the calibrated channel info.
 
Hope this helps.
 
Doug
Enthusiast for LabVIEW, DAQmx, and Sound and Vibration
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