With Hirata-san.

Summary: We aligned the mirror such that the oplev beam was again at the centre of the tilt QPD. However, V1 OSEM went out of range with 300 counts.  A measurement of IM-Y transfer function suggests that the OSEM flags are not touching their bodies.

• We moved the BF with the fishing rod from 3670 um to the setpoint 3350 um in order to set the vertical OSEM flags in nominal conditions.
• OSEM V3 came closer to be in range with  3200 counts.
• As an initial assessment we measured transfer functions IM-V, IM-P and IM-Y: it seemed the OSEMs flags were not touching the OSEM bodies.
• Before moving the IM to recover the oplev readout, we moved SF close to its setpoint. The vertical positions of GAS filters tend to affect the yaw of the mirror via the cables.
• Inside of the clean room we saw that the oplev beam was above the QPD so, we moved the IM in negative pitch ("REV" in medm screen) until the oplev came in range and close to the vertical center of the QPD.
• Unfortunately, OSEM V1 went out of range with about 300 counts.
• We recovered the yaw alignment of the mirror by setting the oplev beam at the horizontal centre of the QPD (IM-Y changed from 1200 urad to 650 urad).
• We measured IM-Y transfer function again and the result suggests the OSEMs flags are not touching their bodies.

In the afternoon we should move IM-V OSEM to bring it into range.