Several High-Sensitivity Rapid Test Tube Of Harmful Gases

In recent years, toxic and hazardous gas leaks, explosions and other accidents have occurred, these gas is not only threaten the personal safety of staff, but also cause environmental pollution. This thesis summarizes the source and harm of the toxic and hazardous gas (hydrogen sulfide, ammonia, chlorine), analysis all kinds of detection method about toxic and hazardous gas, and studies different gas detection tube. In this paper, applying the method of adsorption and enrichment indicator, and enhancing the sensitivity of the test tube. The method is simple, rapid, small sample volume, short response time and high sensitivity, and it is a qualitative and semi-quantitative detection method. The limit of detection for hydrogen sulfide gas detection tubes is 30 mg·m-3, when the sample volume is 50 mL, response time less than 10 min. The limit of detection for ammonia gas detection tubes is 15 mg·m-3, when the sample volume is 50 mL, response time less than 5 min. The limit of detection for chlorine gas is 4 mg·m-3, when the sample volume is 50 mL, response time less than 10 min.The key to this article is the selection of carrier, indicator and dry conditions. Carrier and indicator chosen to meet the gas sample measured after access has obvious color change is appropriate, and not a chemical reaction between carrier and indicator, choose the appropriate drying conditions and different moisture level of indicator, it play an important role in the test results.