Ryser, PeterStraessler, Sigfrid2015-09-222015-09-222015-09-222006https://infoscience.epfl.ch/handle/20.500.14299/118555A gas viscosity sensor comprises a signal processing circuit and a sensor element, including a gas pressure generating system and a differential pressure measuring system in fluid communication therewith, the differential pressure measuring system comprising a measuring chamber (14) bounded by a thin membrane (28), an inlet-outlet channel or orifice interconnecting the measuring chamber to a source of gas for which the viscosity is to be determined, the inlet- outlet channel or orifice having dimensions adapted to provide resistance to the outflow and inflow of gas in the measuring chamber, and a membrane displacement sensor (32) adapted to measure a time dependent displacement of the membrane due to pressure variations in the measuring cavity.patentEP1864107US7730766US2009229351EP1864107WO2006103542EP170794034942954