The Uncertainty of a Residual Life Indicator Measurement by the Thermal Method for a Respirator Cartridge

Protection devices for respiratory organs with filtering and adsorption elements based on solid, particularly chemical, sorbents are examined. In order to ensure reliable operation of the specified respiratory device, it is necessary to monitor their residual life indicator. Factors are analyzed for the uncertainty of indirect measurement of the residual life indicator of the filtering and absorptive products, in the form of a plate and operating under conditions of convective blowoff with cleaning air. It is shown that for sorbent plates based on potassium superoxide KO 2 0.8 mm thick, with relative humidity of the air 60–90%, and carbon dioxide CO 2 concentration 1–4%, the primary uncertainty factor of an indirect measurement of the residual life indicator is the Biot number Bi, which characterizes the conditions of heat exchange from the surface of the plate. It has been experimentally established that for Bi = 0–0.08, the primary factor is up to 30% of the total measurement uncertainty of the residual life indicator.