??-1 gas alarms

Natural gas alarms ??-1: are designed for continuous automatic control of hydrocarbon gas content (natural gas according to GOST 5542 or methane).
The detectors are stationary automatic single-channel devices of continuous operation.
The principle of operation is based on conversion of gas concentration into voltage. The resulting voltage is compared with the threshold value and light, sound and control signals are generated.
The sampling method is diffusion.
The detectors of versions A, ?i, G, GT, E are made in a plastic case, version D - in an aluminium alloy case.
The detectors (except for version D) have a button "Control" and light indicators "Power", "Gas" or "Threshold", as well as, depending on the version: "Failure", "Valve", "Valve closed", "Valve failure", "External threshold", "Communication".
Alarm devices of version D have no external controls and indicators.