1. Confirm the type of gas to be detected

The types of gases encountered by each production department are different, and when selecting a gas detector, all possible situations should be considered. If methane or other less toxic alkanes are present in the environment, choosing a combustible gas detector is undoubtedly the most appropriate choice. If there are toxic gases such as carbon monoxide, hydrogen sulfide, ammonia, chlorine, etc., a specific toxic gas detector must be selected to ensure the safety of on-site personnel. If there are more organic toxic and harmful gases, considering their lower concentrations that may cause personnel poisoning, such as aromatic hydrocarbons, halogenated hydrocarbons, ammonia (amines), ethers, alcohols, lipids, etc., photoionization detectors should be chosen instead of combustible gas detectors. In areas with few personnel and inconvenient maintenance, or with unpredictable gas leaks (such as in enclosed spaces such as tanks), choosing an infrared gas detector is a good choice. If the gas types cover the above types of gases, a composite gas detector needs to be selected.

2. Confirm the concentration range of the gas to be detected

All types of gas detectors have their fixed detection range, and only by measuring within their measurement range can the accuracy and reliability of instrument measurement be guaranteed. If the measurement exceeds the measurement range for a long time, it may cause long-term damage to the sensor. For example, a combustible gas detector (with a measurement range of 0-100 percent LEL) may effectively burn out the sensor if accidentally used in an environment exceeding 100 percent LEL. Toxic gas detectors, such as carbon monoxide detectors (measurement range 0-1000 μ Mol/mol), prolonged use at high concentrations can also cause damage.

3. Confirm the intended use occasion

If entering a confined space, such as reaction tanks, storage tanks or containers, sewers or other underground pipelines, underground facilities, agricultural enclosed granaries, railway tankers, shipping cargo holds, tunnels, etc., before personnel enter, it is necessary to detect whether there are harmful gases or flammable and explosive gases present, and it is required to conduct testing outside the confined space. At this point, it is necessary to choose a multi gas detector with a built-in sampling pump. Because the gas distribution and type in different parts (upper, middle, and lower) of a confined space are closely related. For example, the specific gravity of combustible gases is relatively light, and most of them are distributed in the upper part of enclosed spaces; Carbon monoxide has a similar specific gravity to air and is generally distributed in the middle of enclosed spaces; Gases with high specific gravity, such as hydrogen sulfide, exist in the lower part of enclosed spaces. At the same time, oxygen concentration is also one of the types that needs to be tested.