Changing HVAC settings, HVAC cooling issues, large diurnal outside temperatures, and probably some other things have had our LVEA temperatures moving more than usual lately. I've trended some oplevs and osems to see how much this has our suspensions moving. I'm not sure I can say that this has stopped us from locking or is the cause of our short locks, but our optics are clearly moving and I'm sure that has made relocking more challenging and lengthy.

Attachment 1 - Two week trend of LVEA zones 1A. 1B, 4, 5 (vertex, output arm, input arm) and the PR3 and SR3 oplevs. Before HVAC changes were made zone 4 had the largest diurnal changes (0.6F p2p) and this is seen in SR3 yaw* (0.6 urads p2p). After the changes more of the zones had large diurnal swings, up to 1F. Richard tells me that zone 4 is a smaller volume so it's more difficult to not have the larger swings as its more susceptible to the outside changes.

Attachment 2 - Comparing the PR3 and SR3 oplevs with their top mass osem positions. They agree with each other in some regards, but often the oplevs seem to be more sensitive to temperature. I could imagine the oplevs having a bit of temperature dependence since their hardware are external to the vacuum.

Attachment 3 - 45 day trend of LVEA temps, outside temps, PR3 P oplev, SR3 Y oplev. This shows how our temps and optics are in a different state compared to how they have been.

* This seems a bit odd to me that we we're seeing yaw change the most here with temperature changes.