First of all, before removing the load cell from the weighing system, the structure and sensor of the system should be carefully and carefully determined whether the following problems exist:
(1) Check if the limit device of the system is working and whether the gap meets the requirements;
(2) Check whether the system has damage, rust or obvious wear in the force transmission part; in winter, it should pay attention to whether there is ice formation in the force transmitting part of the sensor, which affects the transmission and reset of the system;
(3) Check if the system is transmitting force failure, which may be due to dust, mechanical parts misalignment, component transmission delay, etc., rather than sensor failure; sensor installation direction is correct.
(4) Check if the sensor cable is connected correctly with the junction box and the display instrument.
Whether there is a bad contact with the disconnected wire;
(5) Check the junction box and the instrument for faults, especially the potentiometer in the junction box.
(6) Check if the sensor is rusted (especially the area of the patch hole); the integrity of the sensor cable; the environment at the entrance of the sensor cable.
Problems with the appearance of the system structure and the sensor are excluded. The following methods can be used for step-by-step testing.
(1) Line rough check
The power supply line, signal line and shielded line of the sensor are coaxial cables, which can be tested with a multimeter (ie power line-signal line, power line-shield line, signal line-shield line), if there is a short circuit, open circuit or A decrease in insulation performance indicates that the sensor may be damaged.
(2) Check the impedance of the load cell
When checking, you need to cut off the power of the electronic scale, open the junction box, and disconnect the signal lines of each sensor. When there is no special detection device, the input impedance Zi and the output impedance Zo of the sensor can be measured with the ohmic file of the 4-digit multimeter, and the measured value is compared with the nominal value on the product certificate provided by the manufacturer. If the side value exceeds the allowable range, it indicates that the sensor may be damaged. (Note: The value of the multimeter used should be accurate, preferably after metering/calibration).
