B-series gas-leakage annunciator is the high quality product for gas safety, which has features of high quality air-sensitive component, stable performance , long validity period, high capability of resisting poisoning ,wide voltage ,visual and audible alarm ,on or off signal output connected with controlgear , The annunciator is easy to operate with detection for using. It is used for combustible gas leakage detecting in underground pipe, which keeps the people safe .Ceiling mounting is very convenience and shortcut . Technology parameter Target gas methane coal gas Alarming concentration 25%LEL Temperature -10oC- 55oC(in house) Humidity ≤ 95/% working voltage AC180-270V/50Hz Storage temperature -25oC-55oC stress 86-106Kpa comsumption static comsumption <1.2W alarm comsumption <2W Validity period 5 years Working place in room