Patent · US Expired

Moisture sensor with valve metal composition electrodes

US4482882A · kind A · utility

14Cited by

4References

12Claims

0Family size

Assignee

Endress u Hauser GmbH u Co. · DE

Inventors

Ernst Luder · Stuttgart, DE
Traugott Kallfass · Bornsteiner Straße, DE
Christian Borgwardt · Markdorf, DE

Key dates

Filing date	Nov 30, 1982
Grant date	Nov 13, 1984
Priority date	—
Expiry date	Nov 30, 2002

Classification

Technology area (CPC G)Physics
CPC primaryG01N27/121
WIPO fieldMeasurement
WIPO sectorInstruments

Abstract

A moisture sensor comprises a moisture-sensitive layer formed from the oxide of highly resistive porous low density tantalum on a moisture-insensitive substrate. Between the substrate and the moisture-sensitive tantalum oxide layer there is a base electrode of an anodically oxidizable metal, preferably tantalum, of a density higher than the density of the low density tantalum from which the tantalum oxide layer is formed. A covering electrode partially covering the tantalum oxide layer has windows through which the water vapor containing medium can penetrate into the moisture-sensitive tantalum oxide layer. The inactive regions of the tantalum oxide layer disposed below the windows are removed to increase the rate of response.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.