Low cost versatile pressure transducer

Abstract

A versatile low cost capacitive type of electrical pressure transducer includes a sensor module providing an output signal indicative of fluid pressure effective thereon, and an elongate cylindrical housing receiving the module and providing for communication thereto of a first fluid pressure (which may have a high pressure level), and of a second fluid pressure (which may range from a vacuum through atmospheric pressure to a pressure level of a few hundred pounds). Consequently the transducer may operate as a gauge pressure sensor or as a differential pressure sensor. Alternatively, other types of sensor modules may also be employed in housings of the same or substantially the same design to fulfill other types of pressure measurement tasks. The commonality of component parts of the various sensors contributes to a reduces cost. Also, the components of the housing are economical to manufacture and assemble, and provide for testing and calibration of the sensors at an intermediate step of manufacture. Thus, further cost savings are realized. The housing provides for electrical shielding of the sensor module from electromagnetic and radio frequency interference, as well as filtering power surges and higher frequency noise. Accuracy and service life of the transducers are thus improved. A connector portion of the housing is secured by a tubular portion thereof by means of low cost rolling operations, and also provides a second source of support to the sensor module in resisting displacement in the housing caused by high fluid pressures. As a result an inexpensive pressure transducer is realized which is applicable to measurement of rather high fluid pressures.