As reported by Yamamoto-san ( see klog http://klog.icrr.u-tokyo.ac.jp/osl/?r=14432 ) F1 GAS output was satured.

I checkd the last 10 days trend data for all Type A' s GAS filter and it seems that a slow drift is going on but I could not found any strong correlation with the temperature variations: (see attached plots).

Anyway to offload the GAS output at IX I changed the offset at F1 and F2.

Below some detail of this work:

I monitored the following channels: ITMX_{F2,F3,BF,F1}_COILOUT, ITMX_{F2,F3,BF,F1}_LVDTINF_OUT, ITMY_BF_DAMP_V_IN1.

F1 GAS coil output was around 27000 counts, while the others were less than 13000 counts.

To reduced this output without change much the BF_DAMP_V (vertical reference position for the TM)

-I changed the F1 position from -2000 um to -2070 um

     the F1 output changed from 27000 counts to 6500 counts

- I changed the F2 position from -1772 um to -1800 um

F2 output changed from 13000 counts to 6500 counts.

For the others TypeA, I didn't changed any offsets.