A Low Pressure Capacitance Type Pressure to Electric Transducing Element

A great variety of pressure transducers with electrical output have been developed for pressure measurements using a number of different operating principles. Virtually all pressure to electric transducers consist of a fluid pressure sensitive member which converts fluid pressure into mechanical movement or force. A new pressure to electric transducer is described. It is a low pressure (0 to I psig) device having a capacitor configuration in which the transducing element is an elastic capacitor consisting of integrally bonded elastic layers, which make up the dielectric core and conducting plates of the capacitor. The element has a nominal capacitance of 100 pF and a pressure sensitivity of approximately 1.3 pF/in of water pressure. The characteristics of the pressure to electric transducer are discussed and include the element's sensitivity to pressure and longterm stability characteristics. The effect of temperature on element performance is also discussed.