How to judge the quality of 4-wire weighing sensor
This article is edited by Shenzhen Huanan Hengtai Industrial Co., LTD., if reproduced, please indicate the source
To judge the quality of the 4-wire load cell, the following methods can be used:
1. Resistance measurement method:
- Use a multimeter to adjust to the appropriate range under the resistance gear.
- Connect each of the four wires on the sensor board to the electrodes of the multimeter. Typically, the red line is connected to the positive terminal (EXC+), the black line is connected to the negative terminal (EXC-), and the white and green lines are connected to the two measurement ports (SIG+ and SIG-) respectively.
- Read the resistance value on the multimeter without an object on the sensor board. This value should be close to the nominal resistance value of the sensor plate. If the resistance value deviates significantly, there may be a problem with the sensor.
- In standard measurement, the resistance at the end of measurement 1 and 4 should be 380Ω±5Ω; The resistance at the end of measurement 2 and 3 should be 350Ω± 3ω; The resistance of measuring ends 1 and 2 and measuring ends 1 and 3 should be equal, about 300Ω± 3ω; The resistance of the measuring ends 4 and 2 and the measuring ends 4 and 3 should also be equal, about 300Ω±3Ω.
2. Output signal judgment method:
- After powering the instrument, remove the output lines of the sensor one by one. Note that special care must be taken during the disconnection process to prevent electric shock, and do not short circuit the output line and the input drive line.
- In no-load condition, use the DC mV file of the multimeter to measure the mV value of its output line. According to the rated excitation voltage, sensitivity and rated capacity of the sensor, the output mV value of each sensor can be calculated in the case of no load. If the calculated value or the rated output of the sensor is exceeded and the output is unstable, the sensor may have a fault.
3. Simple circuit test method:
- Prepare a simple circuit consisting of a battery, a light, and a wire.
- Connect the positive electrode of the battery to the positive electrode of the lamp with a wire.
- Connect the negative electrode of the lamp to the white and green lines (SIG+ and SIG-) on the sensor board.
- Connect the negative electrode of the battery with the black and red lines (EXC- and EXC+) on the sensor board.
- If the circuit can work properly and the light can come on, then the sensor is normal.
4. Elimination method:
- If the faulty sensor cannot be determined using the above methods, you can consider removing the connections of all sensors, and then connecting the sensors one by one to observe the display. If a sensor is unstable after being connected, it is a faulty sensor.
The above method is for reference only, and the specific operation should be carried out according to the actual situation and the sensor manual. At the same time, developing the habit of regularly checking and maintaining the load cell can ensure the normal operation of the sensor.
