I added a calibration line to the MZ PZT - I used the "Dither in" input on the HV PZT Drive Box (D060283)
I am using a function generator (SRDS335) to put a 12Vpp 100 Hz sine wave into this input.
The input goes through a Sallen-Key high pass with a corner of 2.4kHz, so this is around 58 dB down by the time it gets added into the drive signal. I looked at the gain in RMS from this, and it was not dominant in the band of interest.
I took some spectra with a relatively precise (< 5%) calibration of:
2 V/rad for Green diff
4.5 V/rad for IR diff
With a 0.03 Hz BW measurement in DTT, these show up with about an SNR > 10 with peak heights of:
0.00261 for IR
0.00239 for Green
These were spectra taken in Volts/rtHz