Method of and means for detecting water vapour

Abstract

Abstract <PICT:0345672/III/1> An appliance for drying respirable gases for subsequent removal therefrom of noxious compounds is characterized by having disposed in the path of the entrant air, a moisture-absorbent mass, a chemical which undergoes a colour change on contact with water, and an agent for removing the noxious compound disposed beyond the colour change indicator. The indicator may be embodied with the moisture-absorbent proper, either throughout the mass thereof, or in a region remote from the gas inlet; or it may constitute a distinct charge from the indicator proper. Thus it may be coated on an inert material such as pumice granules. As the moisture indicator, dehydrated cobalt chloride or copper sulphate or platinocyanides may be used. Magnesium platinocyanide is specified in the first Provisional Specification. The colour change (from blue to colourless in the case of cobalt chloride) may be noted in relation to a safety mark to indicate the beginning of exhaustion of the absorbent. In a canister for protection against carbon monoxide, shown in the Figure, air is drawn through a layer of drying agent 4, for instance, of dehydrated silica gel, to the indicator material 6 and then to an oxidizing agent 7, which would be rendered ineffective by moisture. A window 9 is provided for observation purposes.

Inventors

No inventors recorded.

Bibliographic Details