Industrial High Accuracy Hydrogen Gas Detector, Explosion Proof Exd IIC T6 Gb, 0-100ppm H2 Concentration Tester Monitor with Sound Light Alarm for Hazardous Area | Runlai Highlights at a glance High Accuracy: Ensures precise measurement of hydrogen levels. Wide Measuring Range: Detects hydrogen concentrations from 0 to 100 ppm and 0 to 4%. Reliable Alarm System: Sound (>70dB), light alarm, and relay output signal for immediate alerts. Long Lifespan: Sensor lasts 2-5 years,