betsy.weaver@LIGO.ORG - posted 14:54, Wednesday 28 February 2018 (40556)
ETMY OSEM Open Light Voltages revisited
Updated Open Light Voltages (OSEMs sitting face down on surfaces so darkish):
| M0 OSEM | NEW OLV | NEW OFFSET | NEW GAIN | OLD OFFSET | OLD GAIN |
| F1 | 27600 | 13800 | 1.087 | -15109 | 0.993 |
| F2 | 25600 | 12800 | 1.172 | -14961 | 1.003 |
| F3 | 27400 | 13700 | 1.095 | -14740 | 1.018 |
| LF | 29300 | 14650 | 1.024 | -15567 | 0.964 |
| RT | 26100 | 13050 | 1.149 | -15396 | 0.974 |
| SD | 27500 | 13750 | 1.091 | -15555 | 0.964 |
| R0 OSEM | NEW OLV | NEW OFFSET | NEW GAIN | OLD OFFSET | OLD GAIN |
| F1 | 29000 | -14500 | 1.034 | -15529 | 0.966 |
| F2 | 25000 | -12500 | 1.200 | -15029 | 0.998 |
| F3 | 26100 | -13050 | 1.149 | -14977 | 1.002 |
| LF | 29100 | -14550 | 1.031 | -15397 | 0.974 |
| RT | 27000 | -13500 | 1.111 | -15525 | 0.966 |
| SD | 27100 | -13550 | 1.107 | -15141 | 0.991 |
| L1 OSEM | NEW OLV | NEW OFFSET | NEW GAIN | OLD OFFSET | OLD GAIN |
| UL | 27225 | -13613 | 1.102 | -14611 | 1.027 |
| LL | 28285 | -14143 | 1.061 | -15059 | 0.996 |
| UR | 24350 | -12175 | 1.232 | -12868 | 1.116 |
| LR | 20780 | -10390 | 1.444 | -11361 | 1.166 |
| L2 OSEM | NEW OLV | NEW OFFSET | NEW GAIN | OLD OFFSET | OLD GAIN |
| UL (#572) | 18500 | -9250 | 1.62 | -10667 | 1.41 |
| LL (kept #428) | 22700 | -11350 | 1.32 | -12291 | 1.220 |
| UR (#522) | 22000 | -11000 | 1.36 | -10612 | 1.413 |
| LR (#526 | 21400 | -10700 | 1.40 | -10163 | 1.476 |
Note, we swapped out 3 of the 4 L2 stage AOSEMs which were showing lower OLVs than we were satisfied with, especially since Stuart at LLO provided me back with the latest batch of 8 tested AOSEMs we had fabbed here which had slightly higher OLVs. We removed AOSEM D0901065 S/Ns 321, 332, and 473. These AOSEMs could be used elsewhere if needed. ICS has been updated.