Optical-fibre flammable gas sensor

Abstract

A flammable gas sensor is demonstrated, in which the sensing element is a 100 mm monomode fibre, coated with platinum metal. The rate of the exothermic reaction of the hydrocarbon gases with oxygen is increased in the presence of a platinum catalyst. The resultant heat of the chemical reaction is transduced to a phase retardance in a fibre-guided light beam, and which is recovered interferometrically. The experiments have been performed in an oxygen (or air) atmosphere at laboratory temperature.