Two precautions for the selection and purchase of gas detectors
1) Confirm the type and concentration range of the gas to be detected:
Every production sector encounters different types of gases. When choosing a gas detector, all possible situations must be considered. If there are a lot of methane and other less toxic alkanes, it is undoubtedly the most appropriate to choose an LEL detector. This is not only because the principle of the LEL detector is simple and widely used, but it also has the characteristics of convenient maintenance and calibration. If there are toxic gases such as carbon monoxide and hydrogen sulfide, it is necessary to choose a specific gas detector first to ensure the safety of workers. If there are more organic toxic and harmful gases, considering the low concentration that may cause personnel poisoning, such as aromatic hydrocarbons, halogenated hydrocarbons, ammonia (amines), ethers, alcohols, fats, etc., you should choose the light gas introduced in the previous chapter. Ionization detectors, and never with LEL detectors, as this could result in personal injury or death.
If the gas types cover the above types of gases, choosing a composite gas detector may achieve twice the result with half the effort.
2) Determine the use occasion:
Different industrial environments require different types of gas detectors.
A) Fixed gas detector:
This is a detector that is widely used in industrial devices and production processes. It can be installed on a specific detection point to detect specific gas leaks. Yiyang fixed detector is generally two-body type. The detection head composed of sensor and transmitter is installed on the detection site as a whole, and the secondary instrument composed of circuit, power supply and display alarm device is installed in a safe place as a whole, which is convenient for monitoring. Its detection principle is the same as that mentioned in the previous section, but it is more suitable for the characteristics of continuous and long-term stability required by fixed detection in terms of process and technology. They should also be selected according to the type and concentration of the on-site gas. At the same time, attention should be paid to installing them in the part where the specific gas is most likely to leak. For example, the most effective height of the sensor installation should be selected according to the specific gravity of the gas.
B) Portable gas detector:
Because the portable instrument is easy to operate and small in size, it can be carried to different production sites. The Yiyang electrochemical detector is powered by alkaline batteries and can be used continuously for 1000 hours; the new LEL detector, PID and composite instruments use rechargeable batteries ( Some have adopted memoryless Ni-MH or lithium-ion batteries), so that they can generally work continuously for nearly 12 hours, so the application of such instruments in various factories and health departments is becoming more and more extensive.
If this type of instrument is used as a safety alarm in an open place, such as an open workshop, a wearable diffusion gas detector can be used, because it can continuously, real-time, and accurately display the concentration of toxic and harmful gases on site. Some of these new instruments are also equipped with vibration alarm accessories-to avoid hearing the audible alarm in noisy environments, and install computer chips to record peak, STEL (15-minute short-term exposure level) and TWA (8-hour statistical weighting). mean) -- provides specific guidance for worker health and safety.
If entering a confined space, such as reaction tanks, storage tanks or containers, sewers or other underground pipes, underground facilities, agricultural closed granaries, railway tank cars, shipping cargo holds, tunnels and other workplaces, inspections must be carried out before personnel enter , and the detection should be carried out outside the confined space. At this point, it is necessary to choose a multi-gas detector with a built-in sampling pump. If there are multiple gases in the environment, choosing a composite gas detector may achieve twice the result with half the effort.
C) Compound gas detector
The composite multi-gas detector can be equipped with the required multiple gas detection sensors on one instrument, so it has the characteristics of small size, light weight, fast response, and multi-gas concentration display at the same time. More importantly, the price of Yiyang composite multi-gas detector is cheaper than multiple single-diffusion gas detectors, and it is more convenient to use. It should be noted that when choosing this type of detector, it is best to choose an instrument with the function of switching each sensor separately to prevent the damage of one sensor from affecting the use of other sensors.
