Humidity sensor, sensor material, method of manufacture and humidity sensing system, especially for automotive use

US4793175A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Horst Fedter · Bühlertal, DE
• Werner Grunwald · Gerlingen, DE
• Manfred Koder · Gerlingen, DE
• Peter Nolting · Bühl, DE
• Claudio De La Prieta · Stuttgart, DE
• Kurt Schmid · Ditzingen, DE

Key dates

• Filing date: Mar 20, 1987
• Grant date: Dec 27, 1988
• Expiry date: Mar 20, 2007

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S252/963
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

An ion conductive sensor is connected to a current source which, in order to prevent polarization effects, controls current flow through the sensor in spaced or polarity-alternating pulses. If the sensor is a humidity sensor, it is preferably constituted by Cr.sub.2 O.sub.3, V.sub.2 O.sub.5 and Na.sub.2 WO.sub.4 in a proportion, by weight, of preferably 2 to 2.5:1:1, sintered on a substrate which has comb electrodes applied thereto. The sensor is especially immune to noise or disturbance pulses from the current supply and is especially suitable for use as an ambient humidity sensor in an automotive vehicle (810).