Temperature on both cavities are fairly constant over -8 hrs, still can't simultaneously lock both cavities.
ACAV RCAV
XXX_SETPT 37.3 35.0
XXX_TEMPAVG 37.301 34.997
SLOWDC -0.11645 (VCOMON center @ 0), -0.1114
XXX_HEATER 4.72971 (FSS)1.49154
Since everything is stable now, I'll lock RCAV and adjust ACAV temperature to lock them together withing AOM range.
I'll change ACAV_SETPT from 37.3->37.4, to see how SLOWDC has to change to lock ACAV.
Wed Sep 01 21:04:24 2010
After 6 hrs, ACAV_TEMPAVG is stable around 37.4 C.
SLOWDC for ACAV is -0.1200 (VCOMON center @ 0)
This means For ACAV, dV(slow dc) per dT(ACAV) = (0.1203-0.11645)/0.1 = 0.039 V/K.
Since RCAV is locked when SLOWDC = -0.1114, we have to decrease the temperature from 37.4 C by (0.1203 - 0.1114)/0.039 = 0.2282 K.
That is 37.4 - 0.2282 = 37.1718.
Now I set ACAV_SETPT to 37.2 C. |