I terminated the data taking around 5PM when the photodiode was at about 4C (277K).
9AM: At 232K this morning at 9AM. Turned on the heater to 1W around 9:07AM to speed up the return to room temperature.
10AM - set heater to 7W
11:50AM - At GPS = 1315334850 - Set heater to 20W. Also noticed that SR560 output was railing so set gain to 500
We're at 170K as of 9AM this morning. At the current rate, we should reach 273K tomorrow morning.