Demonstration of a new principle for an active electromagnetic pressure sensor

A new principle for an active electromagnetic pressure Sensor is described and results from a demonstration prototype are presented. Unlike traditiona l pressure devices, this sensor does not measure the membrane deflection, b ut the force feed back to the membrane to compensate for its displacement. The membrane is thus always kept close to its rest position. Consequently, the measured signal is independent of the mechanical properties of the memb rane, of the fluctuations due to time and temperature, and of the offset du e to fabrication tolerances. Moreover, this enables the selection of the me mbrane material that offers the best resistance for the intended applicatio n. This sensor system is hence especially adapted for harsh environments, h igh temperature applications, and long term measurements. (C) 2000 Elsevier Science S.A. All rights reserved.