03968694 is referenced by 41 patents and cites 8 patents.

A gauge for remotely indicating the pressure in a subterranean formation penetrated by a bore hole, including a tubular closed housing, the lower end of the closed housing forming an integral diaphragm which is subjected to the pressure of the subterranean formation, the housing having an internal reduced diameter portion adjacent the diaphragm forming an integral circumferential ledge, a cup shaped stator element having a closed bottom and opened top, the external diameter of the stator element being slightly less than the internal diameter of the housing and having an enlarged external diameter lip which engages the internal ledge of the tubular housing to precisely position the stator element relative to the diaphragm, the stator element having a conductive surface on the lower end thereof spaced adjacent to the diaphragm forming therebetween a capacitive relationship responsive to pressure deflection of the diaphragm, means of connecting the end of the housing opposite the diaphragm to a conductive cable extending to the earth's surface by which the gauge is lowered in and raised from the bore hole and by means of which electrical signals are passed to the earth's surface and an oscillator circuit within the housing connecting with the capacitive elements formed by the diaphragm and stator to provide an A.C. signal indicative of the pressure detected by the gauge.

Title
Gauge for remotely indicating the pressure of a subterranean formation
Application Number
5/569945
Publication Number
3968694
Application Date
April 21, 1975
Publication Date
July 13, 1976
Inventor
Kenneth K Clark
Tulsa
OK, US
Agent
Head Johnson & Chafin
Assignee
Geophysical Research Corporation
OK, US
IPC
H01G 7/00
G01L 7/08
G01L 9/12
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