Study On Direct-read Passive Detector For Hydrogen Sulfide Gas

Hydrogen sulfide is a colorless gas with an offensive stench and is said to smell like rotteneggs. Workers are exposed to high levels of dust, ammonia, hydrogen sulfide, noise, smell in factory.Worker health risks can be significantly reduced through a comprehensive program of environmentalmonitoring and control by use of management practices, engineering controls, judicial use of personalprotective equipment, and health surveillance. However such programs are exceedingly rare today. A lot ofimported hydrogen sulfide gas detectors are in operation with high cost and required power. So the popularneeds for monitoring hydrogen sulfide should be paid more attention.In the paper, a passive detector of hydrogen sulfide was developed based on the principle of the gasmolecular diffusion and chemical absorption. Through the fundamental research on the passive gasmeasuration technology, the mathematical model of the detector was established, and the gas concentrationand detecting factor were related. The sensitivity of the colorimetric system was evaluated, which has thespecial reaction with hydrogen sulfide. The indicator optimally combined with lead salt shows preferablecolorimetric display. The appropriate carrier and surface-improving reagent was probed. The influences ofvarious conditions on indicating factors were investigated and the optimal conditions were ascertained. Theresults provide that the detection limit for hydrogen sulfide is 0.1mg/m~3 based on eight hours of sampling.The measure range is from 1.5mg/m~3 to 75.0mg/m~3. When the concentration of hydrogen sulfide exceeds1.0mg/m~3, the relative standard deviation is below 10 percent. The coexisted gas don't interfere thedetection in indoor environment at all. The method was used for determining the concentrations ofhydrogen sulfide in working and living rooms, which the relative error is below 10 percent compared withthe national standard method.A novel detector for hydrogen sulfide based on passive sampling was been developed. This detectorhas the merits of structural simple, easy operation and high accuracy. The low cost can be in supermarketsale. This detector can realize the continuous monitor and multi-spots monitor, especially suitable to theworking and living rooms for daily monitoring. The development will be able to obtain the high economicand social benefits.