Abstract: A training device for a self-rescuer is improved such that practical breathing parameters will become established. A granular filling of a material (7) is used that binds water molecules and generated heat of adsorption or heat of absorption in the process instead of an oxygen-releasing chemical.

Abstract: A training device for a self-rescuer is improved such that practical breathing parameters will become established. A granular filling of a material (7) is used that binds water molecules and generated heat of adsorption or heat of absorption in the process instead of an oxygen-releasing chemical.

Abstract: An explosion-proof gas sensor (1) with a flashback barrier (2) permeable to the gas to be measured between the measuring space (4) and the environment in an otherwise gas-impermeable housing (3) is described. The sensor provides reduced response time and higher signal sensitivity for the gas to be measured. A flashback barrier (2) is provided including a plurality of flexurally rigid fabric layers made preferably of metal, which are permeable to the gas to be measured, with an overall thickness of one to ten mm, an overall porosity of at least twenty percent by volume relative to the volume of the flashback barrier (2), and with a maximum number of one percent of all pores with a pore size larger than 240 &mgr;m.

Abstract: A moisture indicator for indicating the state of moisture loading of an oxygen-releasing chemical in a respiratory protection device which contains the peroxide of an alkali metal as the substance is to be improved such that it will indicate an irreversible and clearly recognizable color change and will respond to the intrusion of even small amounts of moisture. To accomplish this task, the substance contains as the reactive substance an additive in the form of an alkali metal ozonide that engages in a color reaction with moisture present in the air.

Abstract: The prior-art CO.sub.2 adsorbent masses used in oxygen-supplying respirators have the disadvantage that they can be granulated only very poorly. The granules have low strength and a tendency to dusting. The goal of the present invention is to produce harder granules which do not give rise to dusting any longer. This is achieved according to the present invention by adding an alkali salt of an oxo acid, preferably sodium hexametaphosphate, to the calcium hydroxide paste prior to the granulation. The present invention is not limited to this salt, but it is also possible to use alkali salts or other oxo acids, such as orthophosphoric acid, sulfuric acid, hypermanganic acid, chromic acid, and vanadic acid. This leads to a substantial increase in the strength to the calcium hydroxide granules without any reduction of their CO.sub.2 binding capacity.