What are the detection standards of gas detectors?
In large-scale industrial sites such as petroleum, chemical industry, power electronics, coal, medicine, metallurgy, pipe gallery, etc., various flammable and toxic gases will be produced, which not only endanger people's health, but also affect the production efficiency of factories and cause unnecessary losses. . .Gas detector can detect the concentration of toxic and harmful gases in real time and is the only safety equipment in the factory.
1. Appearance and function inspection
(1). Inspection of appearance and other items
Visual inspection is the first thing we do after purchasing a gas detector. This is to avoid the presence of gas detectors during transportation or production assembly. For small problems, we need to check the appearance of the gas detector for defects, cracks or damage, and check whether the entire gas detector assembly is structurally complete.
Also check the machine model, label, manufacturer's name and time of manufacture on the body of the gas detector. Check this information against the information provided by the manual or the manufacturer for accuracy. At the same time, check the explosion-proof mark, measurement license mark and serial number of the gas detector, which must be complete and clear. Some certificates can be obtained from the manufacturer.
(2). Power-on inspection
Gas detectors require a power source to work, typically powered by a built-in battery. We have to turn on the switch to check that the gas detector is powered properly. Some gas detectors are made by replacing batteries. Some gas detectors are equipped with a charger if they continue to work. For a gas detector equipped with a charger, we need to test whether the charger is charging normally. When the power supply is normal, we need to check the display of the gas detector. Whether the screen is displayed normally.
(3) Check whether the sound and light alarm of the instrument is normal.
For the gas detector with sound and light alarm signal, since it is powered by battery, when it shows undervoltage, it should be able to send out sound and light indication signal which is obviously different from the alarm signal.
2. Indication error
We purchased a gas detector to detect gas concentration. Gas detectors are not very accurate in displaying gas concentrations. There is an error, but this error has a range. If it exceeds this range, it means that the gas detector does not meet the standard. The specified indication error is different for different gases. For example, it is normal for the indication error of oxygen to be within ±0.5% VOL.
3. Alarm error
We mentioned the error of the displayed value above, so there is a certain allowable error in the alarm value of the gas detector. Because the instrument will be affected by various factors, it is impossible to achieve an accurate concentration low temperature alarm every time, and the alarm concentration is allowed to have errors. , as long as the error is within the standard range. For different gases, the alarm error is also different. For example, the oxygen alarm error is within ±0.1% VOL.
4. Response time
Response time is the time it takes for the gas detector's indication to rise from zero to 90% of the stable indication the instrument should achieve. This time is also required by the standard. The standard and indicated value error and alarm error are different for different gases. For example, the response time of oxygen is less than or equal to 20S.
5. Insulation withstand voltage
Gas detectors must meet some dielectric withstand voltage standards. Standard requirements: normal temperature: ≥100MΩ; after damp heat: ≥1MΩ. The dielectric strength should be able to withstand 500V AC voltage for 1min without discharge and breakdown. Only when these are met, the gas detector meets the standard.
The gas detector is the guarantee of safe production and the guard of the workshop. Once the gas leaks, the sound and light alarm will be issued immediately when the preset value is exceeded, so as to prevent the personal safety of workers and the safety of workshop property from being threatened. It is safety equipment in production and life
