The measurement has been fit with a step response function to get pole/zero of the B1p_PD2_DC channel (see figure).

The filter flt_B1p_PD2_DCwhitening in SDB2_Photodiode configuration has been modified: it was a zero/pole at 1.5700 Hz and 1.8857 Hz ; it is now 1.9028 Hz and 2.3306 Hz. The Acl configuration SDB2_Photodiodes has been reloaded today around 9h23 LT, so that the effect of the new filter can be checked next time the SDB1 fast shutter is closed. Another test to be done: close the photodiode shutter, to check if closing the slower shutter can be enough for such a measurement.