GB1069756A - A method and an apparatus for detecting the presence,in a gaseous sample,of oxygen or of a gas or vapour which reacts with oxygen on heating - Google Patents

Abstract

1,069,756. Gas analysis. O. H. DRAGER, [trading as DRAGERWERK, HEINR & BERNHDRAGERJ. Aug. 4, 1964 [July 23, 1963], No. 31084/64. Heading G1B. A method of detecting the presence, in a gaseous sample of oxygen or of a hydrocarbon in a mixture containing oxygen comprises mixing the sample with a measured quantity of hydrogen, contacting the resultant mixture with a catalyst which is active at room temperature e. g. palladium, to cause a reaction producing water vapour, and then testing the gaseous products for the presence of water vapour. In the apparatus shown in Fig. 1 a gas sample to be tested is contained in a device 7 e. g. a cylinder and piston or bellows device of known volume from which it may be expelled. A bottle 1 contains hydrogen under pressure and this is supplied through a pressure reducing valve 2 to a further device 5 of known volume by way of a multi-way cock 3. With the cock arranged so that hydrogen passes to the device 5, the device 7 is connected to a conduit 8 to enable the gas sample to be collected. The cock 3 is then turned to allow the contents of the devices 5, 7 to pass to a mixing bay 13, and then to a combustion chamber containing the catalyst. The gases then pass to a detector tube for water and if desired in the case of hydrocarbon detection to a carbon dioxide detector tube. In this case the conduit 8 contains a carbon dioxide absorbent filter, and means may be provided for the oxidation of any carbon monoxide to dioxide before passage of the gases through the detector.