OUTLINE OF GAS MEASURING AND GAS DETECTORS
- In the development trend of the industry in general, the issue of safety and accuracy is increasingly appreciated, in which fire safety and health safety have been and are taken care of to a certain extent.
- To contribute to the prevention of fire and explosion hazards caused by flammable gases and to prevent deadly hazards or health effects caused by inhalation of toxic gases or insufficient oxygen concentrations in the working environment, gas measuring equipment, also known as gas detectors, gas detectors were born.
Classification of gas detectors:
In this series, I only limit the line of handheld gas detectors used in fire safety and health, so the classification of machines can be classified in the following ways:
1. Purpose of use: When asking about the machine, manufacturers or suppliers often ask the user to buy a gas detection machine for Personal monitoring or for Confined space which means that the gas detector is used for wear while at work or the type used to check the area before entering the work. For empty areas, if there are risks of flammable gases, toxic gases or oxygen gases, just use the type of personal monitoring gas detection device worn on the person (can be worn in front of the chest, belt or chest, depending on the design of each company), outstanding, there is a Crowcon gas machine with a pretty good design , the top side is very convenient to look at when worn on the body. But for enclosed areas, it is necessary to check that area before going to work (after entering, it is still necessary to wear the machine), often the gas detection machine manufacturers of the G7 to have enough capacity and technology to integrate the suction pump into the machine (China has not yet) , but depending on the machine, the suction capacity may vary, for example, the BW gas detection machine has a suction pump capacity of more than 20m with Dia straws. 6mm should be quite comfortable for most applications. More specifically, the Gasalertmax XT II type BW gas detector also has 2 features in 1 – can be used as Confined space, and can be used as Personal monitoring.
Bộ Confined space kit của Bw Technologies
2. Gases to measure: There are many gases to measure due to or detect but there are this gas measuring instrument that can be divided into 4 main types for easy distinguishing.
2.1. Combustion gas detectors, also known as methane detectors: The machine can measure and detect hydrogen carbon gases (CH4 methane measurement, Propan gas C2H2….) at the same time but will display a burning gas concentration of %LEL or %Vol. When a specific gas measurement is required, some machines will have the option to display the gas name correctly on a screen like %CH4, for example. In this series, there are exceptions to the Hydrogen H2 gas detector, and the volatile bio-gases are also flammable gases but there are my own characteristics that I will say in another post.
2.2. Oxygen Gas Meter: Everyone knows oxygen is very important, in addition to being important for life, in measuring gas, some gases will not be measurable if there is no oxygen in the air (this is a bit meaningless in this article, :D). O2 concentration in the air meets the normal standard of 20.9%Vol, humans will work normally, O2 is so important but it is ottery that humans do not react when oxygen levels gradually decrease but just naturally faint, and how much % is high alarm , how much % is a low alarm, then how many % faints or withstands how many minutes it must depend on the standards that the parties are following.
2.3. Toxic gas detector or toxic gas detection machine: Some commonly used types such as H2S meters, CO meters, NH3 detectors, CO2 detectors …
2.4. Other machines: Some machines used to detect other gases other than O2, non-flammable, non-toxic, and for research or experiments are not mentioned in this article.
3. Classification by measured gas: In fact, if classified according to the measured gas, manufacturers have naming ways such as single-gas detector, multi-gas detector, 2-gas detector, 4-gas detector depending on the amount of gas that the machine measures.
4. Classification by gas measurement sensor: This classification is unther classified but still has little use and is classified into:
4.1. PID Gas Meter: PID stands for Photo-Ionization Detection, which can be referred to as photoeenscent i-type gas detection, which detects VOC gases
4.2. IR Infrared Gas Meter: The machine uses infrared sensors, which are commonly used only for CO2 measurements.
4.3. Gas meters using electrolysed or other catalyst sensors: Use to measure the remaining gases.