The principle of electronic truck scales: Electronic truck scales mainly consist of load-bearing devices, multiple load cells, junction boxes, electronic weighing instruments, large display screens, and foundations, etc. The working principle of an electronic truck scale is that after A heavy-duty truck drives onto the scale platform, the load-bearing device transmits the weight to the weighing sensor. When the weighing sensor is subjected to force, it deforms, causing the strain gauge composed of the Huisideng bridge to lose balance and output an electrical signal to the electronic weighing instrument. The electronic weighing instrument amplifies the signal and converts it into a digital signal via A/D After the CPU normalizes the weight signal, it directly displays the mass value of the heavy-duty truck and transmits the weighing data to the computer management system for processing. Common faults of electronic truck scales include: the instrument does not display or shows negative numbers (underload), unstable and fluctuating display values, inaccurate values, large indication errors, etc. The following analysis will be conducted from several aspects, including external factor faults, mechanical faults, electronic circuit faults, and foundation deformation. The main external factors are the influence of power supply, vibration, external lightning, strong current, etc. on electronic scales. Mechanical faults include deformation of the load-bearing and limit
The device malfunctions or foreign objects are blocking the bearing. Faults in electronic circuits include those occurring in various parts such as weighing display instruments, weighing sensors, junction boxes, signal cables and connectors. There are also faults caused by foundation deformation, subsidence or collapse.
2.1 Faults caused by external factors
In accordance with the principle of "external first, then internal", when an electronic truck scale malfunctions, the influence of external factors should be ruled out first. Changes in the external environment will have a direct impact on the weighing of electronic scales. Changes in the power supply, vibrations and lightning can all cause unstable operation of electronic scales. Therefore, it is necessary to take good lightning protection measures and grounding protection for electronic scales. The power supply is unstable. This problem can be solved by laying a separate power cord for the electronic scale or installing a power stabilizer.
Case One: An electronic truck scale of a certain company has unstable numerical display, with fluctuations ranging from 60 to 80 kilograms. Through an investigation of the external environment, it was found that an excavator was working beside the electronic truck scale. It was intuitively judged that this factor was related. To verify this judgment, the maintenance personnel retrieved the computer weighing historical curve for observation and found that the fluctuation time of this electronic truck scale was consistent with the operation time of the excavator. Therefore, it can be concluded that the main cause of this fault was the strong vibration caused by the excavator's excavation operation. On-site personnel, through coordination, have taken measures to stop the excavator's excavation operations during the weighing process on the vehicle's load-bearing device. It is also stipulated that any construction of civil engineering and other infrastructure near the electronic truck scale must be reported to the functional management department or corresponding protective measures must be taken. Construction can only proceed after a comprehensive technical assessment is approved to ensure the stability and accuracy of the electronic truck scale values.