Sensor Calibration Using DAQ

[leachdor]

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!

VibrationCalibration.PNG:
http://forums.ni.com/attachments/ni/100/1811/1/VibrationCalibration.PNG

[dsb@NI]

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.