In https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=6939, the geophones calibration and the change of basis matrices were checked and confirmed right. This afternoon, the IPS calibration was checked (on BS)

-1: Dial indicators were installed on the HEPI structure.
-2: HEPI is controlled in position
-3: A 500micrometers command is applied in the X direction (tested in Y direction as well)
-4: A19mils (475 micrometers) move is seen at the dial indicators. The 1 mil missing is attributed the hysteresis of the dial indicator

The calibration and the change of basis matrix used by the IPS is right.

Note that the change of base matrix currently installed at BSC6 (since the beginning of the HIFO-Y) underestimates displacements in the X and Y directions by 2.