Reports until 15:38, Thursday 28 June 2018
H1 SUS
travis.sadecki@LIGO.ORG - posted 15:38, Thursday 28 June 2018 (42695)
ETMx Oplev trend after VEA temperature change

Keita asked if I knew why the ETMx Oplev was sitting near the edge of the PD.  We surmised that it is likely due to the recent change in the temperature setpoint in the EX VEA (aLog 42664).  Attached is a trend of the Oplev Pit, Yaw and Sum and the VEA temperature, showing that they start showing changes at around the same time.  As I recall, the time constant for temperature changes to the VEA propagating to the suspension blades is on the order of days to weeks (correct me if I'm wrong) which could explain why the Pit and Yaw continue to trend down while the temperature is stable. 

Images attached to this report