Sensor for Combustible Gases A combustible gas sensor comprises four glass insulated radially extended and symmetrical temperature sensitive elements which are coated with a porous ceramic but only two elements having a catalyst. The sensor is mounted inside a temperature controlled reactor vessel in a region of no temperature gradient into which a combustible gas mixture is admitted and reacted on the catalytic surfaces. The change in the resistance of the elements under the catalyst is a measure of the concentration of the combustible gas.
