What are the testing standards for gas detectors?
1. Appearance and functional inspection
1. Inspection of appearance and other items
Detect the appearance of the gas detector, which is to avoid minor problems during the transportation or production and assembly of the gas detector. We need to check whether the appearance of the gas detector is flawed, cracked or damaged, and check the entire structure of the gas detector components. whole. At the same time, check the machine model, label, manufacturer's name, and factory time on the gas detector body with the instructions or the information given by the manufacturer to ensure accuracy. At the same time, check the explosion-proof mark and measurement license of the gas detector. The contents of the logo and serial number must be complete and clear, and some certificates can be provided by the manufacturer.
2. Power-on inspection
The work of the gas detector requires a power supply, which is usually powered by the built-in battery. We need to turn on the switch to check whether the gas detector is powered on normally. Some gas detectors allow him to continue to work by replacing the battery. The detector is equipped with a charger. For the gas detector equipped with a charger, we need to test whether the charger is properly charged. When the power is normal, we need to check whether the display screen of the gas detector is normal.
3. Check whether the sound and light alarm of the instrument is normal
For the gas detector with sound and light alarm signal, because it is powered by battery, when the undervoltage is displayed, it should be able to send out sound or light indicating signal which is obviously different from the alarm signal.
2. Indication error
The gas detector we purchased is used to detect the gas concentration. The gas detector cannot be very good for the display of gas concentration. It has errors, but this error has a range. If it exceeds this range, it means that This gas detector is not in compliance with the standard, and its specified indication error is different for different gases. For example, it is normal for the indication error of oxygen to be within ±0 and 5% VOL.
3. Alarm error
We mentioned the error of the displayed value above, so there is a certain allowable error for the alarm value of the gas detector, because the instrument will be affected by various factors, and it is impossible to alarm at an accurate concentration every time. Therefore, the concentration of the alarm is allowed to have errors, as long as the error is within the standard range. For different gases, its alarm error is also different, for example, the alarm error of oxygen is within ±0, 1%VOL.
4. Response time
The response time refers to the time it takes for the gas detector's indication value to rise from zero to 90% of the stable indication value that the instrument should reach. This time also has standard requirements. This standard is the same as the indication error and the alarm error. Different gases have different response times.
5. Insulation withstand voltage
For gas detectors, there are also some insulation withstand voltage standards that must be met. Standard requirements: normal temperature: ≥100MΩ; after damp heat: ≥1MΩ. The dielectric strength should be able to withstand 500V AC voltage for 1min, and there should be no discharge and breakdown phenomena. Only after these are met will the gas detector meet the standard.
