Hydrogen sulfide is an inorganic compound with the chemical formula H2S and a molecular weight of 34.076. Under standard conditions, it is a flammable and acidic gas that is colorless. At low concentrations, it has a smell of rotten eggs, and at extremely low concentrations, it has a smell of sulfur. It is highly toxic. The aqueous solution is hydrosulfuric acid, which is relatively weak in acidity, weaker than carbonic acid but stronger than boric acid. It is soluble in water and readily soluble in alcohols, petroleum solvents and crude oil. Hydrogen sulfide is a flammable hazardous chemical. When mixed with air, it can form explosive mixtures. It can cause combustion and explosion when exposed to open flames or high heat.
The safe concentration value of hydrogen sulfide is 10mg/m ³. Converted to PPM units, the low alarm value is 6.6PPM and the high alarm warning value is 13.2PPM. According to the occupational exposure limit (OEL) for hydrogen sulfide (H2S) gas stipulated in the national standard "GBT50493-2019", the maximum allowable concentration is 10mg/m ³, and the direct harmful concentration (IDLH) is 430mg/m ³. Therefore, when using a hydrogen sulfide detector, the first-level (low report) warning value of H2S hydrogen sulfide gas concentration is 6.6ppm, and the second-level (high report) warning value is 13.2PPM.
The first-level alarm value is generally set between 1.5 and 2 times the safe concentration value. For instance, if the safe concentration value is 5PPM, the first-level alarm value can be set between 7.5PPM and 10PPM. When the concentration of hydrogen sulfide gas reaches the first-level alarm value, the alarm will issue an audible and visual alarm to alert the on-site personnel to pay attention.
The Secondary alarm value: Generally set between two and three times the safe concentration value. For instance, if the safe concentration value is 5PPM, the secondary alarm value can be set between 10PPM and 15PPM. When the concentration of hydrogen sulfide gas reaches the secondary alarm value, the alarm will issue a more urgent audible and visual alarm and may activate the emergency evacuation procedure.
We focus on the research and development and manufacturing of various air quality detection equipment. Our products cover multiple sensor terminals for toxic and harmful gases, meteorology, dust, noise, water quality, etc., and we provide complete solutions. The setting of the safe concentration value and alarm value of hydrogen sulfide gas detectors is of vital importance for ensuring industrial safety and the health of workers.