The troubleshooting method of electronic weighing instrument
Electronic weighing instrument troubleshooting method-repair method for the detected faults, such as: abnormal power supply, fuse damage, limit gap is too loose or too tight, junction box is damp, there is debris between the scale body and the foundation, connecting cables Failures such as damage and joint welding points can be dealt with on site. Electronic weighing instrument troubleshooting method-replacement For unrepairable parts such as sensor damage, instrument damage, junction box damage, cable damage, etc., you can only replace them with good ones. The troubleshooting method of electronic weighing instrument-debugging. After repairing the faulty truck scale, especially after replacing the components, it must be calibrated and debugged. Attachment: Steps for fault judgment 1. Method to judge whether the meter is good or bad: If the meter is faulty, the following methods can be used to judge. Method 1: Connect the meter with a simulator and observe the change of the displayed value, such as whether there is drift, whether there is display, etc. If the displayed value is stable, the meter is good. Method 2: Replace with a spare PCB board, input the original parameters into the new PCB board, use the same method to observe the change of the indication value, so as to judge whether the instrument is faulty. 2. The method to judge whether the sensor is good or not (1) The method of judging the analog sensor (the following sensors are represented by LC) measuring resistance value: between ±EX (780) ±5Ω, ±Si between (700) ±2Ω, The resistance value of the sensor is subject to the nominal resistance value of the sensor actually used. Measured voltage value: the range between ±Si is generally 0-25 mV, after power-on, the empty scale is generally 0-5 mV. Test the insulation performance of the sensor: set the digital multimeter on the 20MΩ gear, put one end of the meter rod on the shell or shielding wire, and the other end on any one of {±EXC, ±SI}, if the multimeter displays 1, it means that the insulation resistance is infinite , The sensor is good, and vice versa is bad. Observe whether the sealing cover of the sensor has fallen off. Check whether the sensor wire is broken, wire-bonded, etc. Check each corner of the scale for four-corner errors, if so, whether it can be adjusted, and if there are four-corner errors after adjustment, replace the sensor. Disconnect the sensors of the scale one by one, and observe the change of the indicated value. For example, if the original display is drifting, and the current display is stable, it means that the disengaged sensor is damaged. 3. Junction box failure. First open the junction box and observe whether it is damp or dirty? If it is damp or dirty, use a hair dryer to dry the junction box, and wipe the junction box clean with an alcohol cotton ball. After the above treatment, if the problem cannot be solved, replace the junction box. 4. Limit Open the sensor cover on the scale body and check whether each LC limit is dead. The horizontal limit gap is ≤2mm, and the longitudinal limit is ≤3mm. 5. System maintenance (1) After the weighbridge is installed, the manual, certificate, installation drawing and other materials should be properly kept, and it can be put into use only after it has been verified by the local measurement department or an approved measurement department. (2) Before the system is powered on, the grounding device of the power supply must be checked for reliability; after get off work stops, the power supply must be cut off. (3) Before using the weighbridge, check whether the scale body is flexible and whether the performance of the supporting parts is good. (4) The weighing display controller must be turned on and warmed up first, usually about 30 minutes. (5) In order to ensure the accurate measurement of the system, there should be anti-lightning facilities. It is strictly forbidden to use the weighing platform for neutral grounding when welding near the weighing instrument to prevent damage to electrical components. (6) For the ground scale installed in the field, the drainage device in the foundation pit should be checked regularly to avoid blockage. (7) Keep the junction box dry. Once moist air and water droplets enter the junction box, use a hair dryer to dry it. (8) In order to ensure the normal measurement of the weighing instrument, it should be calibrated regularly. (9) When hoisting and weighing heavy objects, there should be no impact; when weighing on-board heavy objects, the rated capacity of the system should not be exceeded. (10) The axle load of the truck scale is related to the sensor capacity, the distance of the sensor fulcrum and other factors. Generally, truck scales prohibit the over-balance of short-wheelbase vehicles such as forklifts that are close to the weighing. (11) Squad operators and instrument maintenance personnel must read the manual and related technical documents before they can work. 6. Fault inspection and troubleshooting (1) Find the location of the fault: If the truck scale fails to work, first find out where the fault occurred. The easy way is to find it with the help of an emulator. The steps are as follows: Disconnect the signal cable from the junction box to the instrument, insert the socket of the simulator (9-pin D-type flat socket) into the weighing display controller interface J1, turn on the power, and see if the weighing display controller is working properly. It means that the fault lies in the weighing platform. If the weighing display controller does not work normally, the fault lies in the weighing display. The troubleshooting must be carried out by specialized inspection personnel. The above is a troubleshooting method for the electronic weighing instrument to share for everyone. I hope it can help everyone.