After modifying the signs of the gains from the medm, I took a new set of transfer functions of phase 3b (under vacuum) M2 mass of the beamsplitter over the last week end (cf alog 7677 and 7693). During the measurement, the ISI was damped. The plots of the attached document are described below :

- H1 SUS BS M2-M2 undamped transfer functions phase 3b with corrected gain signs (Sept 06th 2013 19:00, in black) compared against H1 SUS BS M2-M2 undamped tf (Sept 06th 2013 15:00, in orange) against the model in blue.

The last measurements are showing a very good match with the model