Failure analysis and countermeasures of combustible gas detectors used by users
(i) Improper use by users
Users use the detector process, the air conditioning and heating equipment near the combustible gas detector installation, when the use of air conditioning and heating equipment in the process, if the cold, warm airflow directly blowing through the combustible gas alarm, it may cause the combustible gas alarm platinum wire resistivity change error, so the combustible gas alarm should be away from the air conditioning, heating equipment, to avoid improperly set up to cause failure. Users should also pay attention to the process of combustible gas detector to prevent electromagnetic interference. Combustible gas alarm installation location, installation angle, protective measures and system wiring should be anti-electromagnetic interference. Electromagnetic environment on the combustible gas alarms have three main ways of influence: air electromagnetic interference, power supply and other input and output lines of the narrow pulse group and the human body static electricity. For example: combustible gas alarm close to the air-conditioning installation, will cause the detection of the system deviation; detection lines and power lines, lighting lines and other strong power lines with small spacing, without adding anti-electromagnetic interference measures, the system will also produce detection deviation. Users should pay attention to the factors that are easy to cause malfunction in the process of using the combustible gas detector, such as: dust, high temperature, humidity, rain and so on. When installing combustible gas alarms need to install exhaust fans, exhaust fans, such as combustible gas detector and combustible gas detector adjacent to the set, the leakage of combustible gases will not be able to fully diffuse to the vicinity of the combustible gas alarms, resulting in the detection of the time can not be missed, Yee missed the opportunity to fight. Users should also pay attention to the combustible gas detector settings in explosion-proof places, such as the distribution of combustible gases in Category A plant should be used explosion-proof combustible gas alarms, the explosion-proof level should not be lower than the current specification of the corresponding explosion-proof level requirements. Users should also pay attention to the use of combustible gas detector to avoid high temperature, high humidity, vapour, fumes can reach the place. Do not place objects or hang objects on the detector. The installed combustible gas detector should not be moved arbitrarily. Users use combustible gas alarms try to choose the sensor probe can be replaced to facilitate the use of the product.
(B) construction process is not standardised
Construction process is not standardised in the use of combustible gas detector detection failure. Such as combustible gas detector is not located in the equipment is easy to leak combustible gases near, or installed with the exhaust fan set up adjacent to the leak of combustible gases can not be sufficiently diffused to the combustible gas detector nearby, so that the leakage of dangerous situations can not be detected in time by the combustible gas detector. For residential combustible gas detector should be installed in the kitchen gas piping, cooker nearby, when households use natural gas, gas detector suction ceiling installation from the ceiling within 300mm of the place; when households use liquefied petroleum gas, gas detector should be installed from the ground within 300mm of the place. Combustible gas detector if not reliable grounding, can not eliminate electromagnetic interference, will affect the voltage, the detection data is not allowed to appear fault. Therefore, the combustible gas detector should be reliably grounded during construction. Combustible gas detector and terminal set in easy to suffer collision or easy to enter the water, resulting in electrical circuit breakage or short circuit. Welding must use non-corrosive flux, otherwise the joints corrode off or increase line resistance, affecting the normal detection. Do not drop or throw the detector to the ground. Debugging should be carried out after construction to ensure that the combustible gas alarm is in normal working condition.
(C), maintenance
Combustible gas detector to detect combustible gas information, must make the detector and detection of environmental communication, so the environment of a variety of contaminating gases and dust into the detector can not be avoided, the detector caused by the working conditions of the damage is the objective existence of combustible gas detector working environment is relatively harsh, there are many installations in the outdoors, poor maintenance will lead to combustible gas alarms detecting errors or non-detection. Poor maintenance will lead to errors or non-detection of combustible gas alarms. Therefore, regular cleaning and maintenance of the combustible gas detector is an important work to prevent failure.
Grounding should be regularly tested, grounding is not up to standard requirements, or not grounded at all, will also make the combustible gas detector susceptible to electromagnetic interference, resulting in failure. Prevent component aging. From the reliability considerations, while practice has proved that combustible gas detector service period of more than 10 years of the system by the aging of the components caused by the failure tends to increase, so the service period of more than the use of the requirements of the regulations, should be replaced in a timely manner.
