Method and apparatus for sensing the presence of oxygen in a gas mixture

US4464926A · kind A · utility

Assignee

• DRAGERWERK AKTIEGESELLSCHAFT · DE

Inventors

• Scato Albarda · Groß Schenkenberg, DE
• Alfred Eder · Friedberg, DE

Key dates

• Filing date: Nov 3, 1982
• Grant date: Aug 14, 1984
• Expiry date: Nov 3, 2002

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N27/74
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A sensor for sensing the presence of oxygen in a test gas mixture comprises either first or second tubes for the separate flow of a measured gas and a gas to be tested for a single tubular arrangement for the successive flow of these two gases in association with a plurality of radio-frequency coils which are connected in an electrical bridge circuit to that they can be balanced in any variation of the inductance measure. Since oxygen in the gas produces a paramagnetism which provides induction variations in the coils of the balancing circuit, the variations of the balancing circuit may be used to sense the proportion of the oxygen content in the gases. With the inventive method the gases are passed into association with the balancing circuit and variations of the test gas from the measured gas are sensed by the circuit balance which is produced by the oxygen which is present in the gas mixtures. Such a sensor may be used for breath protection, diving and medical fields.