Today my aim was to lower the damper ring to its nominal position above to the SF and assess by how much the SF moves due to a possible magnetic force. The displacemt would be a change in the F0 LVDT readout.
Because I wanted to do the measurement in one go, I moved back the receptacles to their previous position, e.i. the bottom faces flushed with the bottom face of the F0 base plate.
Unfortunatelly, F0 LVDT is not providing a sensible output:
- A two point calibration yielded the factor 25 µm/cnt, whereas the factor previously determined was 0.147 µm/cnt (entry 7182).
- The polarity of the measurement was reversed: when the keystone goes up, the change in number of counts is negative.
- The resonant frequency is approximately 1.08 Hz (measured by visual inspection) instead of the 0.56 Hz measured before (entry 6886).
- The temperature today was 23.7 ºC.
- The notebook notes are here.
Apparently no wire was detached from the connector. In one week I'll check the health of the LVDT driver. I released the IP.