Infrared radiation happens everywhere at all times, and the energy of infrared radiation can be absorbed by certain gases or compounds. 

Optical Gas Imaging technology (OGI) is an effective method to detect the leak of gases. It works with a narrowband window (filter) designed for gas with  specific absorption peaks. 

By identifying the relative temperature difference between gas and background, and through specialized image filtering and enhancement processing algorithm, the gas is visualized and thus can quickly detect the presence of leaked gas and accurately locate the leak source.

Volatile Organic Compounds (VOCs) refer to organic compounds that can evaporate into the air at room temperature and pressure, and are a major source of air pollution. 

There are many types of VOCs, including formaldehyde, benzene, toluene, xylene, ether, acetic acid, etc., and their characteristic absorption peaks are mainly located at 3.2-3.4 μm. They are widely present in natural environments and industrial production, causing serious impacts on the environment and human health. Timely and accurate detection of VOCs leaks is of great significance for environmental protection work.

In VOC gas detection, when gas leaks, the temperature around the leak point often changes, forming an abnormal temperature area. Optical gas imaging device captures these infrared radiations and converts them into thermal images, which can visually display the location and size of gas leakage points.

CO is a toxic gas with a characteristic absorption peak located at 4.5-4.7 μm, mainly from vehicle exhaust and industrial emissions. High concentrations of CO can pose a threat to human health and the atmospheric environment. 

In industrial production, especially in situations involving gas, coal, and other substances that may produce CO, infrared technology can be used to monitor temperature changes around equipment or pipelines and detect CO leakage hazards in a timely manner.

CO2 is a greenhouse gas, with its characteristic absorption peak located at 4.2-4.4 μm. The increase in CO2 concentration will lead to global warming. Infrared technology is widely used to detect CO2 leakage in fields like environmental protection and chemical engineering. For example, in the detection of natural gas pipelines and equipment, infrared technology can quickly locate CO2 leakage points and help workers take timely measures for repair. 

SF6 is a gas widely used in fields such as power transmission and distribution, insulation, semiconductors, and healthcare etc. It is also a powerful greenhouse gas with a global warming potential 23500 times higher than CO2. Therefore, it is crucial to detect and repair SF6 gas leaks. 

SF6 has strong absorption of infrared radiation at 10.6 μm. The application of infrared thermal imaging technology in SF6 leakage detection is mainly reflected in its ability to quickly and accurately locate and detect the leakage point of SF6. 

This method can achieve non-contact, long-distance, fast and accurate positioning of the leakage location of electrical equipment in operation, providing sufficient information support for the formulation of status maintenance of leaking equipment.