A couple weeks ago, Bubba changed the HVAC controls at the endstations, removing the B sensor from the loop, and just using the A C and D sensors. This seems to have helped the temperature stability of BRSX. First attached trends are for the last 2 days, the outside temps dropped about 10C, the driftmon moved about 3000 counts peak to peak, but the average position didn't really seem to move much. The second image are trends from 2 days around the 7th of this month, before Bubba's change. For this earlier time, the outside temps dropped about 10C outside, BRSX moved about 8000 counts peak to peak, with the average moving maybe 4000 counts.
Nice set of data Jim.
From the first set of plots, it looks like your EX BRS drift sensitivity to temperature is 0.2degC / 3750 cts * 32000 cts / CCD= 1.7 degC / CCD.
In other words when the box temperature changes by 1.7 degC, the brs would drift full range on the CCD.
For comparison, our least sensitive BRS at LLO is IY ~ 1.3 degC / CCD and most sensitive EY ~0.5degC / CCD.