Abstract: A signal transmission system with at least one signal encoder, a line, and a control and evaluation unit, wherein the signal encoder has an electronic unit and a power source, wherein the signal encoder feeds an imprinted current in the range between a preset first value and a preset second value into the line, in particular between 4 and 20 mA. The control and evaluation unit has a load and a microprocessor, and captures and evaluates a voltage that decreases via the load or a current that flows through the load. Additional information regarding the status of the components, can thus be captured and forwarded in a simple way, in that the load in the control and evaluation unit is connected in series to at least one electrical component at which a direct current appears when a current flows through the electrical component.

Abstract: A signal transmission system with at least one signal encoder, a line, and a control and evaluation unit, wherein the signal encoder has an electronic unit and a power source, wherein the signal encoder feeds an imprinted current in the range between a preset first value and a preset second value into the line, in particular between 4 and 20 mA. The control and evaluation unit has a load and a microprocessor, and captures and evaluates a voltage that decreases via the load or a current that flows through the load. Additional information regarding the status of the components, can thus be captured and forwarded in a simple way, in that the load in the control and evaluation unit is connected in series to at least one electrical component at which a direct current appears when a current flows through the electrical component.

Abstract: In accordance with the invention, gas masks have a gas sensor behind the filter. When the filter reaches its allowable absorption limit, the gas sensor emits a signal.

Abstract: Lithium batteries used for an aeration or breathing apparatus, such as gas masks or protective suits, are enclosed in a housing, and the enclosure has a predetermined breaking point to release gases which may accumulate in the interior. The housing surrounding the lithium batteries has a closure, which opens when the compressed gases are released, to allow the gases to be safely discharged to the outside.

Abstract: A catalytic-combustion sensor has a rigid support having a flat support face, a metallic resistance-type heater film flatly adhered to the support face, and a catalyst film flatly adhered in heat-transmitting connection to the heater film. The heater element is made of platinum or gold and the catalyst film is made of a platinum-group compound such as a palladium-, platinum, rhodium-, or iridium-compound, in an arrangement used to detect methane, although different materials can be used for other gases such as propane or butane. Normally a diffusion-blocking layer overlies the catalyst film. The heater film is a strip following a nonstraight, normally meandering, path on the support face and support is a rigid bar having a back face opposite to the support face and formed thereon in registration with the nonstraight heater film with a rearwardly open groove that reduces the thickness of the bar at the heater film.