Gas detector purchase knowledge

1) Confirm the type and concentration range of the gas to be tested:

The types of gases encountered in each production department are different. All possible situations should be considered when selecting a gas detector. If methane and other less toxic alkanes are the most common, the LEL detector is the most suitable. This is not only because the LEL detector is simple in principle 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 select a specific gas detector to ensure the safety of workers. If there are more organic toxic and harmful gases, considering the lower concentration of people who may cause poisoning, such as aromatic hydrocarbons, halogenated hydrocarbons, ammonia (amines), ethers, alcohols, fats, etc., you should choose the light introduced in the previous chapter. Ionize the detector and never use the LEL detector, as this can cause casualties.

2) Determine the use occasion:

The type of gas detector is different depending on the industrial environment.

A) Fixed gas detector:

This is the use of more detectors on industrial plants and in production processes. It can be installed at a specific inspection point to detect specific gas leaks. Yiyang fixed detector is generally two-body type. The detection head consisting of sensor and transmission is installed in the inspection site. The secondary instrument consisting of circuit, power supply and display alarm device is installed in a safe place for easy monitoring. Its detection principle is the same as that described in the previous section, but it is more suitable in the process and technology for the continuous and long-term stability required for fixed detection. They are also selected according to the type and concentration of the gas on site, and care should be taken to install them where the specific gas is most likely to leak, such as selecting the most effective height for sensor installation based on the specific gravity of the gas.

B) Portable gas detector:

Because the portable instrument is easy to operate and compact, it can be carried to different production sites. Yiyang electrochemical detector is powered by alkaline battery and can be used continuously for 1000 hours. The new LEL detector, PID and compound instrument use rechargeable battery ( Some have used non-memory nickel-metal hydride or lithium-ion batteries, so that they can generally work continuously for nearly 12 hours, so as such instruments are used more and more widely in various factories and health departments.

If it is open, such as an open work shop using such instruments as a safety alarm, you can use a diffused gas detector that you wear, because it can display the concentration of toxic and harmful gases in the field continuously, in real time and accurately. Some of these new instruments are also equipped with vibration alarm accessories - to avoid audible alarms in noisy environments, and computer chips to record peaks, STEL (15 minutes short-term exposure levels) and TWA (8-hour statistical weights) Average) - Provides specific guidance for worker health and safety.

If it is entering a confined space, such as a reaction tank, storage tank or container, sewer or other underground pipeline, underground facilities, agricultural closed granary, railway tanker, shipping cargo bay, tunnel, etc., it must be tested before personnel enters. And to test outside the confined space. In this case, you must select a multi-gas detector with a built-in sampling pump. If there are multiple gases in the environment, choosing a hybrid gas detector can achieve twice the result with half the effort.

C) Composite gas detector
The multi-gas detector can be equipped with multiple gas detection sensors on one instrument, so it has the characteristics of small size, light weight, fast response and multi-gas concentration display. More importantly, the price of the Yiyang compound multi-gas detector is cheaper than that of multiple single-diffusion gas detectors, and it is more convenient to use. It should be noted that when selecting such detectors, it is best to select instruments with individual sensor functions to individually switch to prevent other sensor usage from being affected by one sensor damage.

Gas detection instruments are often used in environments where harmful gases endanger personal safety or may have adverse consequences. Gas detection equipment is often used. The gas detection instrument is an indispensable detection instrument for preventing environmental pollution at an early stage and ensuring human life safety. Gas detectors are usually used for the detection of toxic or flammable gases. Toxic gas detectors are commonly used in biochemical, pharmaceutical, construction and other industries, while flammable gas detectors are commonly used in gas environment testing in coal, petroleum, chemical, fuel and other industries. . The testing standards for different industries are different, and the testing standards for different gases are not the same. When selecting a good gas detection instrument, please choose the instrument according to the purpose and occasion of use. First, determine the type of gas to be tested and the concentration criteria:

The gases to be detected in different environments are different. Before choosing which gas detector to use, the first thing to do is to determine which gas to measure, which is more suitable for the concentration range, and even Consider all the conditions that may occur.

For example, in the environment where methane or other less toxic alkane gas is more abundant, it is better to choose the LEL detector; and the environmental test of toxic gases such as CO and H2S should ensure the testers and the personnel of the environment, so choose Specific gas detectors; for environments with more organic harmful gases (such as aromatic hydrocarbons, ammonia, *, etc.), it is necessary to choose a photoionization detector to not only obtain more accurate detection results, but also avoid The possibility of casualties using the LEL detector. Finally, if a variety of gases are likely to be present in the environment, it is best to choose a hybrid detector.

Second, consider the application of different detectors:

The fixed gas detector is a relatively large-scale detection instrument used in industrial production and installation. It is an instrument that is installed at a fixed monitoring point to detect a fixed gas. The circuit, sensor and alarm device jointly complete the gas monitoring. And the height position of the sensor installation is selected according to the density of the gas. As the name suggests, portable gas detectors are small in size, easy to carry, easy to carry to different environments, and because their power supply is powered by alkaline batteries, the working time is longer, so its application is more and more extensive.