Before understanding the hydrogen sulfide alarm, first understand the hydrogen sulfide gas. Under the standard condition of hydrogen sulfide, it is a flammable acid gas, colorless, and has the smell of rotten eggs at low concentrations. If the concentration is extremely low, it will have the smell of sulfur and is highly toxic. Mixing with air can form an explosive mixture, which can cause combustion and explosion in case of open flame and high heat. If there is hydrogen sulfide in the environment, it will pose a huge threat to human health, and even cause life safety, and may also cause explosions and cause blasting accidents.

The harm of hydrogen sulfide to human health. Hydrogen sulfide is a strong neurotoxin and has a strong stimulating effect on mucous membranes. It can be dissolved in water, 0 ℃ 1MooreWater can dissolve about 2.6 moles of hydrogen sulfide. The aqueous solution of hydrogen sulfide is calledHydrosulfuric acidIt is a weak acid, and when it is heated, hydrogen sulfide escapes from the water. Hydrogen sulfide is an acute toxic, inhalation of a small amount of high concentration of hydrogen sulfide can be fatal in a short time. Low concentrations of hydrogen sulfide to the eyes,respiratory systemandcentral nervous systemAll have an impact. And hydrogen sulfide breaks down when it meets moisture on the surface of the mucous membranes of the eyes and respiratory tract,And react with alkaline substances in the tissue to produce hydrogen, sulfur and hydrogen ions, hydrogen sulfate and sodium sulfide, which have strong stimulation and corrosive effects on the mucosa, causing different degrees of chemical inflammatory response，In addition to the intracellular ventricular interest, the deep tissue damage zui is heavy,SuchEasily cause pulmonary edemaIt will also damage the myocardium, such as myocardial infarction, myocardial ischemia, edema and so on. And hydrogen sulfide will cause pollution to the atmospheric environment.

Hydrogen sulfide mainly exists in mining and non-ferrous metal smelting, low-temperature coking of coal, sulfur-containing oil mining, refining, rubber, leather, dyes, sugar and other industries have hydrogen sulfide production, excavation and remediation of swamps, ditches, printing and dyeing, sewers, tunnels and the removal of garbage, manure and other operations. In addition, natural gas, volcanic jets and mineral springs exist. At present, in the coal mine field and environmental pollution, there is a clear safety index for hydrogen sulfide. The allowable concentration of hydrogen sulfide zui in the air in the national standard is 10 mg/m, while according to the "Coal Mine Safety Regulations", the concentration of hydrogen sulfide in the underground air cannot exceed 0.000066.

Electrochemical gas sensor is the core component of hydrogen sulfide alarm. Electrochemical sensor uses electrochemical principle to convert the content of measured gas into electrical signals. There are many kinds of electrochemical gas sensors. Most of them are constant potential electrolytic gas sensors for toxic gas detection. It has the characteristics of high sensitivity, good selectivity, simple structure and relatively short service life. The hydrogen sulfide gas alarm should be used within the validity period of the instrument sensor, which is generally valid for two years.

WeApolloCompany Agent of the United KingdomAlphasenseHydrogen sulfide sensor has high precision, good linearity, good stability, strong anti-temperature and humidity, and strong anti-interference ability. It is widely used in coal mines, chemicals, sewers, natural gas, non-ferrous metal smelting, etc., and can monitor the hydrogen sulfide gas in the environment in real time to protect people Life and health. Which commonly used to hydrogen sulfide sensor is a two-year lifeH2S-A1。

The main performance parameters are as follows:

Measurement range: 100ppm

Sensitivity: 550 ~ 875nA/ppm

Response time:< 25s

Linear range: -4ppm

Overload: 500ppm

Resolution: 0.05ppm

Size: Φ20.2*16.5

Service life: 2 years

Storage period: 6 months

Working temperature:-30~50 ℃

Working humidity: 15 ~ 90% RH

Load resistance: 10 ~ 47Ω