Background:

Coal mining became a major industry in the early 18th century. As coal is the main energy source, the low cost and high abundance of this material make coal mining important for the growth of economic industries. Although energy use has since shifted from coal to electromechanical generators, coal remains a valuable source of energy through modern open-pit mining methods. An early method of mining coal involved tunneling underground; However, due to spontaneous combustion during mining, during the oxidation of coal, this process produces harmful vapors (i.e., carbon monoxide at a concentration of 0.1%, which can cause death within minutes of exposure; Carbon dioxide; And hydrogen sulfide). The use of sensors designed for gas detection in mines has evolved from miners' canaries to infrared sensors. Now we can use carbon monoxide sensors.

A miner's canary

Canaries (Serinus canaria) are commonly used by miners to alert them to the presence of toxic vapors, such as odorless carbon monoxide, in dangerous areas of underground mining pits. The Use of JXCT is a low-tech gas sensor solution designed to ensure the safety of miners in uncertain working environments.

If there was an explosion or fire in the mine, rescue workers would enter the mine with canaries in cages. Canaries are known to be sensitive to carbon monoxide poisoning, so any distress shown by canaries alerts miners to the toxic gas and gives them enough time to return to safety. Mice have also been used as carbon monoxide detectors; Canaries, however, showed more obvious signs of distress at small amounts of carbon monoxide. In the presence of toxic concentrations of carbon monoxide, for example, canaries will rock from side to side and then fall from their perch.

By 1987, the government had phased out the use of canaries in mines to help detect toxic gases. Canaries have been deemed ineffective and unsafe in detecting the presence of pollutants in the atmosphere. In addition, maintenance costs are high, which is not ideal in a narrow underground working environment. Modern techniques for detecting toxic gases developed quickly. They are considered a cost-effective long-term solution for mine gas monitoring.

Gas sensor based on infrared LED

Infrared (IR) LED gas sensor with dual beam design has become the preferred method for gas monitoring. The use of this modern technology helps to shape current practices in the mining industry, particularly when considering the safety of the mining environment.

Compared with the existing old gas monitoring methods, infrared based gas monitoring has certain advantages, such as:

Infrared gas sensors have a wide measurement range from a few parts per million to 100 percent of the gas concentration;The response speed is fast, from the gas into the analyzer to the measurement of gas concentration is about 0.1 seconds;
Background gas does not affect IR LED gas sensor; andIndividual gases can be accurately measured.

The development of gas sensors seems to have shaped the mining industry, enabling technologies such as infrared gas sensors to work effectively for five years and improve the accuracy of measuring toxic gases. Catalytic sensors  are more susceptible to contamination and struggle to compete with IR technologies due to limited detection principles.

Fixed CO2 gas sensor

Explosion-proof carbon dioxide gas alarms are specially developed and produced for harsh environments. The professional testing carbon dioxide concentration sensor probe is used as the core detection device; it has the characteristics of wide measurement range, high precision, good linearity, good versatility, convenient use, easy installation, long transmission distance and moderate price. Industrial-grade sensor for continuous monitoring of gas concentrations. The certificate is complete, there are a variety of options, and can be purchased on demand. There are a variety of options for the alarm controller, and the optional external control ports are rich.