The way that the combustible gas detector works
Combustible gas detectors are detectors installed in industrial and civil buildings that respond to single or multiple concentrations of combustible gases. The working principle of the combustible gas detector In the design of the combustible gas detector, the sensor and the microcontroller are the core components of the instrument. The flammable gas concentration signal converts the toxic and flammable gas concentration signal into a voltage signal through the gas sensor. After passing through the preamplifier circuit, it directly outputs a digital signal or outputs a voltage signal suitable for the single-chip microcomputer through A/D conversion, and then sends it to the single-chip microcomputer. , the analog voltage signal needs to be processed by the linearized data, and then the voltage signal is converted into the corresponding hexadecimal concentration value. Send the concentration value to the LCD display for display. When the detected concentration of toxic and combustible gas exceeds the upper limit alarm setting value, the alarm will sound and light alarm, and the display screen will display the corresponding status. The work of the combustible gas detector 1. Strengthen the verification of the gas. Before performing the error verification of the indication value according to the provisions of the verification regulations, the range calibration should be carried out with a standard gas with a concentration of 60 full scale. Some alarms use a potentiometer to adjust the indication value, while others The calibration point has been set in the internal program of the alarm when it leaves the factory. Generally, it is set at 50 of the full scale according to the Chinese standard. At this time, the calibration point should be modified according to the manual, and then calibrated. After 3 times a set of concentration value measurements, the gas in the tube must be exhausted before the next set of concentration value measurements can be performed, otherwise the verification result will be affected. Sometimes because the pressure reducing valve is not enough, the pressure reducing valve that has just passed the gas is directly disassembled and installed on the gas cylinders of different concentrations of gas, because there is a part of the "dead volume" in the inside of the pressure reducing valve and the spring tube of the pressure gauge, which will still occur. There is a certain amount of residual gas, and the residual gas needs to be evacuated at this time. The specific method is to connect the pressure reducing valve to the gas cylinder of the next set of gas, close the valve of the pressure reducing valve, open the valve of the gas cylinder, and fill the pressure reducing valve with gas. Then close the valve of the gas cylinder, quickly open the valve of the pressure reducing valve, and release the gas quickly, and repeat the above operation 3 to 5 times. 2. Implement metrological verification management In order to implement metrological verification management, it is also necessary to divide the measurement management responsibilities of combustible gas detectors, so that fire protection, quality inspection and security inspection departments can do a good job in the health use management and metrological verification of alarms. Specifically, the construction department is required to supervise the supply department, the gas production department and the construction unit to do a good job in the measurement and verification of the alarm. At the same time, the fire department is required to do a good job in the supervision and inspection of the setting and use of the alarm. Furthermore, the government should require the quality inspection department to do a good job in the supervision of the measurement and verification of alarms, and strengthen the publicity and education of verification management. In addition, it is necessary to ask the safety supervision department to do a good job in the health inspection of the alarm. 3. Strengthen product quality management In the aspect of measurement management of combustible gas alarm devices, we should ensure the healthy use of alarm devices by strengthening product quality management of alarm devices. For enterprises that install and sell combustible gas detection alarms, they need to issue corresponding qualification certificates and make records. Before using the alarm, the device needs to be verified by the legal metrology technical institution, and can be put into use after passing the test. Once the device verification fails, it is necessary to rectify the unit using the device, and then perform the device verification again. In addition, once it is found that there is a problem in the device manufacturer, it is necessary to cancel the business license of the enterprise, so as to carry out the quality management of all the detector products. In short, with the continuous progress of the research and development technology of combustible gas detectors, more and more alarms with beautiful appearance, clear display interface, simple operation, modular structure design and easy maintenance have been applied to chemical, pharmaceutical and other fields to reduce the hidden danger of accidents. probability of occurrence.
