Liquefied gas alarms type ??-3

Signallers ??-3 are designed for continuous automatic control of the vapour content of liquefied hydrocarbon gas (natural gas - according to GOST 5542-2014, fuel gas - according to GOST R 52087-2003) in the air of boiler rooms and other municipal and industrial premises.
The principle of operation of the detectors is based on the change in resistance of the semiconductor sensitive element (sensor) as a result of adsorption on it of molecules of the component to be detected. The voltage drop on the sensitive element is proportional to the concentration of the detected component in the air. The voltage value obtained during measurement is compared with the voltage values set during threshold setting. When the concentration exceeds the threshold level, sound, light and control signals are generated in accordance with the logic of the signalling devices operation.