2025-07-28
How to judge the quality of a weighing sensor?
Operation method for detecting good and bad:
1. The sensor manufacturer provides sensor output sensitivity and power supply voltage at the factory, and we detect the sensor output signal based on these two parameters. The strain gauge weighing force sensor outputs an analog signal in millivolts.
For example, the sensitivity of the sensor output is 2.0mVN, and the power supply voltage is DC10V. These two parameters can provide us with a linear relationship between the sensor excitation working voltage of DC10V and the sensor output signal corresponding to a 2.0mV excitation voltage output for every 1V.
For example, if the full range of the sensor is 50KG, then give the sensor a DC10V voltage and output 20mV at full range. Based on this relationship, we use a multimeter mV to measure the sensor output signal. The no-load output of the sensor is 0mV, which is normal. If it is greater than this value, but close to this value, the numerical change indicates that the sensor has zero drift. If the value is large, it indicates that the sensor is damaged or the internal bridge is a circuit with asymmetric bridge arm resistance.
2. Determine whether the sensor strain gauge is damaged based on the sensor parameters provided by the factory, input resistance, and output resistance. The input and output resistance values of sensors vary from manufacturer to manufacturer.
So this needs to be tested according to the manufacturer's labeling. Use a multimeter to measure the resistance of the power supply and power ground, as well as the resistance of the signal line to ground. If the resistance is greater than the factory resistance value, it indicates that the weighing sensor has been overloaded and the strain gauge is deformed. If the resistance is infinite, the sensor strain gauge is severely damaged and cannot be repaired.
3. Because the lead wires of the weighing sensor often break during use, and the outer layer of the protective sheath wire is intact, we visually inspected the integrity of the sensor wires. We used the ohm range of a multimeter to detect the continuity of the sensor wires. If the resistance is infinite, it is certain to break, and if the resistance changes, the contact is poor.
The above are common faults that can be easily detected by using a multimeter to check the weighing sensor.