Plots in the attached file show a large glitch in the FLOWRATE that also shows up in other signals. Glitch seen in QPD segments, and LASERTEMPVOLTAGE.
During the glitch in the FLOWRATE, the LASERTEMPERATURE instantaneously dropped by almost -0.5C, which is not physically possible.
The QPDs also glitched.
There's one box that reads the laser temperature and the QPDs, D1300649.
I don't know if this is the same box as the one in alog 33816, from Feb 2017, because I might have missed an alog where it was swapped out.
The box in alog 33816 was uninstalled, tested, and reinstalled, and had some voltage changes due to how it was positioned on the table, and voltage changes when someone was touching the outside of the box.
The signals I saw glitch today do not go through the TCS controller box, D1200745.
The laser temperature is on line 28 in the block diagram although the numbering is identified in the Bill of Materials: https://dcc.ligo.org/E1400342 - apparently to prevent redundancy but inadvertently making it much more difficult to track down cable numbers. This does go back through the CO2 controller.
So we're seeing glitches that involve two separate boxes.
