LIGO Document E1000329-v1
- This Unit#5 was built at the end of July 2011, and was tested immediately after, at the beginning of August 2011, just before switching to building BSC-ISI at LLO.
One difference of interest, it is the only unit tested on the eLIGO HAM test stand (D070395), all other units were tested on D1002124.
A few issues were found during the testing of this unit 5. They are summed up here:
1. Sensor gaps not recorded on the jig
2. Measure of the sensors gaps not done
3. CPS 12068 & 12061 have an Amplitude Spectral Density too high at 0.1Hz
4. Stage 0 was not fully level, probably due to the stand (different from the one used for the other unit)
5. Position sensor Unlocked/Locked Powerspectra is slightly too high at low frequencies
6. Could not check pressure on V1 & V3 GS-13.
7. The X Offset on the LZMP is three times bigger than the acceptance criteria.
Only item 7 motivated our decision to re-test that unit. We will use the same test stand used for the previous units, and investigate whether the capacitive position sensors, or the actuators may be responsible for the issue.
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