The first figure shows the results of 2.5 cycles of crystal chiller total flow variation (24.2 l/m vs. 22.2 l/m) in DARM and in the 1QX signal of the DBB quad diodes. The diode signal shows a detectable increase with flow from about 60 to about 6000 Hz, with the biggest increase in the 1000 Hz region. DARM increased from about 200 to 2000 Hz, with the biggest increase around 450 Hz.

The second plot shows other DBB diode signals.  The peaks do not change as much as the rest of the jitter spectrum (see 1000 Hz). The lower percentage changes at some of the peaks are more consistent with the changes in table accelerometer signals. The water signal is apparently a less dominant driver of the peaks than of the smooth regions, and the source of the peaks may therefore be easier to access and damp should need be. 

Robert, Jason