Reports until 19:03, Friday 12 August 2016
H1 ISC
stefan.ballmer@LIGO.ORG - posted 19:03, Friday 12 August 2016 - last comment - 15:38, Saturday 13 August 2016(29078)
ASC-AS_C calibrated in W into HAM6

Using the calibration of alog 28133 (3.0554e+04 cts / Watt from SRM, or 3.273e-05Watt/ct) I added FM10 filters to the segments of ASC-AS_C to cast the output into Watt entering HAM6. I also updated H1:ASC-AS_C_SUM_OFFSET (which avoid astronomic PIT and YAW values).

SDF is updated.

Comments related to this report
koji.arai@LIGO.ORG - 23:47, Friday 12 August 2016 (29083)

[Stefan Koji]

LHO ALOG 28953 and LHO ALOG 28133 show descripancy of factor of two.

When we have 10W input this should give us 24mW

10W (P_in) * 0.9 (T_IMC) * 0.03 (T_PRM) * 1/2 (R_BS) * 0.985 (ITM) * 1/2 (T_BS) * 0.37 (T_SRM) * 0.97 (T_FI) = 24mW

This is closer to the measurement on LHO ALOG 28953. (We still don't know the origin of this difference of x2.)

We decided to use the number in this log (0.0162mW/cnt) to calibrate H1:ASC-AS_C_SUM_OUT to indicate incident power to HAM6.
Also the calibration factor for H1:LSC-ASAIR_B_LF_OUT was entered to match those two.

peter.fritschel@LIGO.ORG - 15:38, Saturday 13 August 2016 (29088)

It looks like Stefan's earlier log (28133) missed a factor of 2 gain in the QPD transimpedance amplifier (D1001974) due to the balanced differential output of this amplifier (which feeds the Whitening/VGA). With that factor of 2, Stefan's estimate would be very close to the measured value of 0.0162 mW/count.