This afternoon Ryan Short, Jackie, Maya and Camilla took another set of measurements with the M2 profiler for different ZM4 + ZM5 strain gauge values.  We wanted to change ZM2 psams to be somewhere in the middle of the voltage range that looks good based on Begum's 5th attachment to 90613, the measurements were mostly taken with ZM2 at 37 volts on the PZT and the ZM2 strain gauge at 2.4V.  

I've attached the data that Ryan sent here, and a preliminary plot of where the mode is on an Sw plot at SRM with the changed ZM2 psams.  This can be compared to the same plot with ZM2 at 3.15V and it looks quite different.  

Most of these points were taken with ZM2 at 2.4V on the strain gauge as the legend says, there is one outlier which was at 3.15V ZM2, ZM4 2.0V. and ZM5 -4.4V.   This point does seem to be in the same area as the same point taken last Friday.  

So, it seems that by moving the ZM2 psams to better mode match to the filter cavity we are moving the mode out of ZM5 by a lot more than the range of ZM4 and ZM5.  So, we will need to set the preloading and lens positions for a particular choice of ZM2 psams.