I used Sheila's matlab script to plot PR3 Pitch as a function of IFO power.

The plots are from 12 days of data ending June 14th at 17:45UTC.  This includes locks at 17W and 24W.

Locked  = 'in lock, high power' 

Data are locks with input power between 17W and 18W, or locks at 24W or more.

Unlocked = 'low power, locked or unlocked'

Data are from input power less that 3W.

PR3 Pitch position is unchanged locked vs unlocked at 3W.

I removed other data points as transitional power states.

First plot: PR3_PIT_IFO17W.png

Locked pitch position is distributed around -2.8urad.

Unlocked pitch position is distributed around -1.4urad.

Difference = -1.4urad

Second plot: PR3_PIT_IFO24W.png

Locked pitch position is distributed around -3.2urad.

Unlocked pitch position is distributed around -1.4urad.

Difference = -1.8urad

Summary:

The PR3 Pitch position in-lock is changing with the change IFO power.