There was a pressure glitch on PT100B HAM1 cold-cathode at 07:25:15 PDT this morning. There was no corresponding glitch on any other corner station gauge as far as I can tell.
Pressure increased from 3.3e-08 to 4.0e-08 Torr, recovered in 4 minutes.
This is clearly very concerning.
Attached is a trend of the pressure in the top right, along with several other channels (IMC power in, ISC_LOCK guardian state, RM alignments, DC power levels on all 4 PDs in that chamber), and I don't see anything in any of these channels that looks suspicious.
EDIT to add second screenshot, of in-vac tabletop L4C seismic sensors. Again, nothing suspicious-looking to me that I see yet.
Given no lockloss correlation, may not be significant; ~3 orders of magnitude less PV than the June event(s). Maybe an ion pump burped up some argon.
IP13 ion current/pressure spiked up ~1 second before the PT100B gauge did, see attached. Likely argon instability of the pump