The deformable mirrors are sensitive to humidity and should in principle operate under humidity controlled environment (<40%). To guarantee optimal operation and durability for our DMs, a local solution for hygrometry control has been developed for all the deformable mirrors of the bench. A laminar flow of dry air is continuously injected over the sensitive part of the mirror and a mechanical nose covers all the DM but remains open on the front. A sensor built into this nose permanently determines the hygrometry level thanks to a measurement acquisition unit external to the bench. The developed system is presented on the image for a Kilo-C DM from Boston Micromachines (left) and IRIS AO PTT489 DM (right).
