With Hirata-san

See pictures in album PR3 Remedying Work.

• We inspected the bottom side of IM wire clamps to check whether there was anything anomalous. Inspection of that part of the payload is difficult but everything looked alright. See pictures in the album.
• We used the laser level to set up an oplev to measure the pitch of the mirror with respect to the horizontal. It's specs are
  • Model: Hitachi UG 20UA
  • Error: ±1 mm over 10 m
  • Because the error is relatively low and the distances involved are less than 10 m, we didn't try to account for a correction.
• As written in the notebook notes, the distance from the back side of the mirror to the oplev ruler was 1575 mm.
• The front side of the mirror has to point up by 1/300 rad because the X-End room is the highest point of the IFO. Given the armlength of the oplev, this happens when the reflected beam from the back side of the mirror is 10.5 mm below the horizontal (see this notebook page).
• The hirizontal beam reaches the oplev at 78.5 mm (see the notebook notes), therefore, we require the reflected beam to be at 68.5 mm.
• Such a position was reached by a combination of picomotor and Trump method. The sequence and the methods used are written below.
• Tomorrow we should measure transfer functions with the horizontal OSEMs and, if successful, we will proceed with the adjustment of the V1 OSEM which is out of range.

Oplev readout sequence

95mm: Start position
↓pico
82mm
↓pico
77mm
↓Trump
29mm
↓pico
33mm
↓pico
38mm
↓Trump
69mm
↓pico
68mm: Target position