Sensor for determining carbon monoxide

US5351029A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Gerhard Huth · Stuttgart, DE
• Detlef Baresel · Stuttgart, DE

Key dates

• Filing date: Jun 22, 1993
• Grant date: Sep 27, 1994
• Expiry date: Jun 22, 2013

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N33/004
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

The invention relates to a sensor for the determination of carbon monoxide, especially in gas mixtures containing oxygen, on the basis of doped metal oxides whose electric conductivity is a function of the composition of the gas mixtures. Suitable metal oxides are those having n-type conductivity, the dopants used being other oxides of a metal having a maximum valency <4; oxides of a metal catalyzing the reaction of carbon monoxide with oxygen to give carbon dioxide, each in amounts from 0.01 to 0.2 mol %; and from 0.001 to 0.1 mol % of an oxide of a metal of the 5th subgroup of the Periodic Table of Elements. The sensors are notable for a small resistance-temperature coefficient while having high sensitivity and low hysteresis.