Common fault analysis and troubleshooting methods of gas detectors
During the use of the gas detector, it is inevitable that it will malfunction. Below are a few simple examples of troubleshooting methods. Of course, in case of instrument malfunction, the first thing to ensure is that the sampling system is in good condition, that the filter and other gas paths are not blocked, there is no condensate, and that the gas path is correctly connected and has the correct flow rate. Then check the detector and related equipment for looseness or disconnection of their power or pipeline connections. The following fault analysis points are hoped to be helpful to users.
1. During operation, the displayed value gets stuck on the screen, and adjusting the potentiometer zero position does not work. If the connector has poor contact or the wiring terminal is not properly connected, check and eliminate it. If necessary, replace the connector; Measure if there is an open circuit, short circuit or poor release in the bridge, identify and eliminate it. If there is a problem with the bridge arm inside the ring chamber, it needs to be sent to the manufacturer for repair.
2. The heating indicator light on the front panel of the gas detector does not light up for a long time: the heating plate is open circuit. Check the heating plate and its terminals to eliminate poor contact. If there is an internal open circuit in the heating plate, replace it; The heating indicator light is damaged and needs to be replaced; Open circuit of temperature control platinum resistor, check if the wiring terminal is reliable. If there is an internal open circuit in the platinum resistor, replace it; Loosen the terminal connection to the heating plate and tighten the terminal screw.
3. Unstable instrument display: The working current of the measuring bridge is unstable. Check whether the voltage at test terminals A and B on the power supply and signal amplification board is stable at a certain value between 1.2V and 1.3V. If it is unstable, replace N2 (adjustable voltage regulator block at terminal 3173); The voltage of the operational amplifier power supply is abnormal. Check if the 12V voltage is stable. If it is abnormal, replace the damaged component; Measure if there is poor contact in the bridge or related terminals, check if there is any virtual soldering or poor contact in the relevant components. If not, rule it out and replace the components if necessary.
4. After connecting the power supply, the digital display of the gas detector does not show: there is a fault with the power switch, replace the power switch; The power fuse is blown, replace the fuse; Remove the malfunction of the microcomputer power system and tighten the terminal screws; Microcomputer system malfunction, sent to the manufacturer for maintenance.
