The Gastec 4H tube provides reliable and precise measurement of hydrogen sulfide concentrations over a wide range from 10 to 4000 ppm using a simple colorimetric detection method with no need for calibration.

 Product Highlights:

• Measuring Range: 10 to 4000 ppm (with scale typically from 100 to 2000 ppm)


• Detecting Limit: Approximately 2 ppm using 10 pump strokes


• Shelf Life: Typically, 3 years when stored in a cool, dark place


• Number of Pump Strokes: Variable depending on concentration range; usually 1 to 10 strokes


• Reaction Principle: The tube reagent reacts with hydrogen sulfide to form lead sulfide (PbS), causing a color change from white to brown along the tube length, directly proportional to gas concentration


• Relative Standard Deviation: Approximately 5% in the mid-range (100–2000 ppm), indicating good precision