GB1092527A - Improvements in pressure sensitive transducers - Google Patents

Abstract

1,092,527. Measuring temperature and pressure electrically. SIMMONDS PRECISION PRODUCTS Inc. Dec. 8, 1964, No.49824/64. Heading G1N. Relates to capacitive transducers which are variable in response to fluid pressure. In Fig. 1 a differential pressure responsive transducer in the form of a manometer, comprises a metallic casing 20 containing a first pair of insulating sleeves 25 having a conductive layer 25' therebetween, and a second pair of insulating sleeves 24 with a conductive layer 24', the conductive layers forming capacitor electrodes and having terminals 21, 22. A mercury column 33 occupies an annular space 32 between the said pairs and is linked by a passage 29 to a mercury reservoir 28. High and low pressure from a differential pressure source such as a fluid flow channel orifice, is communicated through conduits 26, 27. Any change in pressure difference results in a corresponding change in the height of mercury column in the space 32 and thus a corresponding change in the capacitance between the conductive layers. The variable capacitor transducer may be connected in one arm of a bridge circuit, Fig. 3 (not shown) and unbalance caused by variation thereof is nulled by adjustment of a capacitor in another arm of the bridge, e.g. by means of a servomotor.