1:Gas detectors with lcd 2:Imported sensor 3:ISO9001:2008 ... action according to program. Feature:1.Adopts imported sensor with high measurement accuracy, high stability, strong anti-poisoning ... signal wire both use non-polarity design.And with automatic protection function to avoid damaging controller caused ... ,H2S,O2(VOL),NH3 ppm),Cl2,NO,SO2 Working condition temperature:-40°C~+70°C(Catalytic); -20°C~+ ...