US 4,393,714 AGranted

Differential pressure sensor

AssigneeKernforschungszentrum Karlsruhe GmbH

InventorCurt Schmidt

Life of this patent

Estimating the term…

Loading patent…

Abstract

A differential pressure sensor comprises a housing having first and second inlets; a rod-shaped capacitive displacement sensor affixed to the housing in the interior thereof; a first electrode constituted by an end face of the displacement sensor; a second electrode constituted by a diaphragm extending generally parallel to and at a distance from the first electrode; a bellows affixed to the housing and the diaphragm along a circumference thereof; a first chamber defined within the housing and communicating with the first inlet; and a second chamber defined within the housing and communicating with the second inlet. The first and second chambers are separated fluid tight from one another. One of the faces of the diaphragm is exposed to the pressure of a first fluid admitted to the first chamber through the first inlet and the other face of the diaphragm is exposed to the pressure of a second fluid admitted to the second chamber through the second inlet. As a result, the diaphragm is displaced and the distance from the first electrode is varied as a function of the difference between the pressures of the first and second fluids to vary the capacitance of the capacitive displacement sensor.

Claims8

Dependent claims

A differential pressure sensor comprising in combination:

(a) a housing including means defining first and second inlets;
(b) a rod-shaped capacitive displacement sensor affixed to said housing in the interior thereof;
(c) a first electrode constituted by an end face of said displacement sensor;
(d) a second electrode constituted by a diaphragm extending generally parallel to and at a distance from said first electrode;
said diaphragm having opposite faces;
(e) a bellows affixed to said housing and said diaphragm along a circumference thereof;
(f) a first chamber defined within said housing and communicating with said first inlet;
and
(g) a second chamber defined within said housing and communicating with said second inlet;
said first and second chambers being separated fluid tight from one another;
one of said faces of said diaphragm being exposed to the pressure of a first fluid admitted to said first chamber through said first inlet and the other of said faces of said diaphragm being exposed to the pressure of a second fluid admitted to said second chamber through said second inlet, whereby said diaphragm is displaced and said distance from said first electrode is varied as a function of the difference between the pressures of said first and second fluids to vary the capacitance of said capacitive displacement sensor.

8 more elements

Dependencies are inferred from the claim text.

Facts

Application: 06/323,692Filed 20 Nov 1981
Priority: EP 81101676.57 Mar 1981
Granted: 19 Jul 1983
Term ends: Not estimatedThe source records don’t support an estimate.

Classification4 codes

G01L 9/0038
Transmitting or indicating the displacement of bellows by electric, electromechanical, magnetic, or electromagnetic means: using variations in…
Y10S 505/842
Apparatus per se, device per se, or process of making or operating same: measuring and testing
G01L
Measuring force, stress, torque, work, mechanical power, mechanical efficiency, or fluid pressure
Y10S
Technical subjects covered by former uspc cross-reference art collections [xracs] and digests