Reports until 16:19, Wednesday 29 January 2014
H1 PSL
kiwamu.izumi@LIGO.ORG - posted 16:19, Wednesday 29 January 2014 (9637)
ISS PD offset jumped

Stefan, Kiwamu

We found that the ISS diffracted light had been high at 24%. According to the trend, it looks that both PD_A and PD_B suddenly got an offset of about 0.5-ish volt and it pushed the diffraction ratio to the high value. The jump happened at around 9:41 local in this morning. Neither Keita nor Yuta was at around the ISC/PSL rack at this specific time. At this point it is unclear what happened or what might have triggered it. The attached is the trend showing the funny jump which also decreased the carrier power everywhere.

For now, we changed the reference offset to bring it to approximately 9%. The new reference offset is:

H1:PSL-ISS_REFSIGNAL           -2.31548

A further investigation is needed.

Images attached to this report