Daily Operation Precautions for Gas Detectors
1, Installation of gas detector: Firstly, wiring: Highly shielded wires should be used to prevent interference with electrical signals. The wires should be arranged properly and the top cover should be opened. Gas detectors generally use a three wire transmission system. The positive terminal of the power supply (marked as "VCC" terminal), the signal line (marked as "SIG" terminal), and the negative terminal of the power supply (marked as "GND" terminal) are connected to a set of terminals labeled as "4-20mAIN" in the channel module, corresponding to "24V, mA, and GND". The chassis ground (shielding network of the cable) is well grounded, and after connecting the wires, the chassis is fastened. Start: Wiring completed, power supply to detector. After startup, the reading will go from over range to stable, which takes about 15 minutes. The second is to install the gas detector in an area where there may be gas leakage. The installation of the gas detector must be firm, and the installation position is determined by the specific gravity of the measured gas relative to air. As the specific gravity of the measured gas is smaller than that of air, the detector should be installed at a distance of 30-60cm from the ceiling. Fix the detector on the wall with a Φ 8 expansion screw. To properly use the detector and prevent its malfunction, please do not install it in the following locations:
Places directly affected by steam and oil fumes; Places with high airflow, such as air vents, ventilation fans, and doors; Places with high levels of water vapor and droplets (relative humidity: greater than 90%); Places with temperatures below -40 ℃ or above 70 ℃.
2, Factors to consider before using a gas detector: Before entering confined spaces and/or containers, it is necessary to check whether the work area is safe and whether corresponding arrangements need to be made, such as equipping a set of ventilation equipment. Are there any toxic or explosive substances in the area? If so, what are they? What is the oxygen level there? If the security level measurement can be implemented correctly, then these two questions can be answered. If the container has been completely emptied, it still plays an important role in risk assessment, regardless of whether there are pollutants releasing gases or hazardous substances entering.
3, How to maintain a gas detector: Whole machine inspection: The detector should be checked regularly, and its signal current is DC4mA in clean air; Sensor maintenance: Generally, re inspection and calibration are required after six months to one year of installation and use, and a testing report should be issued by the testing party; When the sensor of the gas detector loses sensitivity, it needs to be replaced. Regular calibration will determine whether the sensor has failed. When the calibration value does not reach the standard gas value, the sensor needs to be replaced.
