Views: 0 Author: Site Editor Publish Time: 2022-10-18 Origin: Site
1. Weighbridge instrument failure
To find out where the instrument failure occurs, the easiest way is to find it with the aid of a simulator. Disconnect the signal cable from the junction box to the instrument, insert the plug of the simulator into the 232 interface of the instrument, turn on the power, and see if the instrument functions normally. If the instrument works normally, it means that the fault lies on the weighing platform. The fault lies in the meter. The most convenient and effective way to diagnose instrument faults is to use the substitution method. If it is suspected that there is a problem with the PCB, replace it with a good PCB, and then use the simulator to check or observe whether the failure phenomenon disappears. Note that after replacing the new PCB, you must perform parameter setting and weighing calibration again in accordance with the instructions. Normally, if there is a problem with the meter, return it to the factory for repair.
2. Signal line failure
There are many reasons for signal line failure, such as loose contact, false welding, and poor contact caused by cable damage. Typical examples are: (1) The connecting wire is clamped between the positioning base plate and the foundation. Two wires are broken due to compression, and the scattered cement solidifies. When the temperature is high, the two broken wires are short-circuited and cause failure. , When the temperature is low, it will shrink and lose contact, so that the meter will return to normal. (2) Welding or desoldering, use the "replacement method" and "wire pulling method" to find out that the fault is caused by a certain sensor. The signal line of the sensor may be bitten by a mouse. Sometimes it can be touched, it is normal, sometimes It is in the disconnected state, and the meter displays the load overload. Find the damage, cut the sensor signal line from the bite, and treat it with epoxy resin (or wrap it with waterproof tape) to make a joint, and the truck scale will return to normal. Since it is quite troublesome to find the damaged part of the signal line, the usual method is to use a spare signal line to directly connect the sensor and the junction box to judge.
3. The floor scale junction box failure
First check the junction box for moisture intrusion, if there is moisture, wipe it with alcohol, and then dry it with a hair dryer. Look for short circuits in the wiring. In the junction box, use a multimeter to measure the resistance of the shielded wire and other wires and the weighing platform to see if there is any leakage or short circuit. At the same time, check each wire and the ground wire or the outer stainless steel shield of the signal cable for leaks and short circuits.
4. Scale body failure
Observe with the naked eye whether there are foreign objects stuck in the bottom of the truck scale body, the scale body and the protective frame at both ends, the scale body is deformed, the scale body is shifted, the connection piece is broken (shear beam sensor), the level of the scale body is damaged, and multiple sections The connection between the scale bodies is loose and the sensor is shifted.