Analysis and troubleshooting of common faults of gas detectors!
During the use of the detector, the gas detector will inevitably fail. The following are some simple examples of troubleshooting methods. Of course, if the instrument fails, the first thing to do is to ensure that the sampling system is in good condition, to make sure that the gas path such as the filter is not blocked, there is no condensate, and the gas path is properly connected and has the correct flow. Then check the detector and related equipment for looseness or disconnection of their power connections or plumbing connections. The following points of failure analysis, I hope to help users:
1. During operation, the displayed value is stuck on the screen, and adjusting the zero position of the potentiometer does not work: the connector is in poor contact or the terminal is not properly connected, check and eliminate it, and replace the connector if necessary; the measuring bridge has an open circuit , short circuit or poor release, find out and eliminate it. If there is a problem with the bridge arm in the ring, 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, and the discharge contact is not good. If the inner circuit of the heating plate is open, replace it; if the heating indicator is damaged, replace it; If the platinum resistance resistance is open circuit, check whether the terminal is reliable. If the platinum resistance resistance is open circuit, replace it; the connection of the terminal connected to the heating plate is loose, and tighten the terminal screw.
3. The instrument display is unstable: the working current of the measuring bridge is unstable, and check whether the voltage of the two test terminals A and B on the power supply and signal amplifier board is stable at a certain value between 1.2V and 1.3V. If it is unstable, replace it. N2 (adjustable voltage stabilizing block at 3173 end); the power supply voltage of the op amp is abnormal, check whether the 12V voltage is stable, if not, replace the damaged components; measure the poor contact of the bridge or related terminals, and check whether the related components are empty Welding and poor contact, if not, eliminate it, and replace the components if necessary.
4. After the power is turned on, the digital display of the gas detector has no display: the power switch is faulty, replace the power switch; the power fuse is blown, replace the fuse; the microcomputer power supply system is not released properly, tighten the terminal screws; overhaul.
