Gastec Hydrogen Sulphide Gas Detector Tube features 2 - 10 pump strokes and 1/2 - 1/10 correction factor for 0.25 - 2.5 ppm measuring range, 1 pump strokes and 1 correction factor for 2.5 - 60 ppm measuring range and 1/2 pump strokes and 2 correction factor for 60 - 120 ppm measuring range. Detector tube has sampling time of 1 min per pump stroke for 0.25 - 60 ppm and 30 sec per pump stroke for 60 -120 ppm. It is ideal to detect hydrogen sulfide in air or the industrial areas and environmental atmospheric condition. Detector with 0.1 ppm detecting limit, changes color from White to brown.