When connecting a multimeter to a non-defective load cell and applying a load, the signal should increase in proportion to the load and return to the initial signal read on the display when the load is removed.
Overloading or shear load can cause a defect inside load cells which can not be detected with the naked eye.
A defective load cell does not transmit a stable electronic signal that can be translated into a weight by the display. A scale with a damaged load cell can therefore not be recalibrated.
Load cell function test:
- Loosen the two screws on the top of the platform.
- Open the box on the left (not the Xtrem module):
- For each load cell you will find one terminal block (4x) and one connection to the Xtrem module.
- Check the contacts
- Check the supply voltage (Vdc) of each load cell by measuring between +EXC and EXC with a multimeter. This should be between 4.7 Vdc and 5.0 Vdc.
- Disconnect the load cells and connect them one after the other. Mark the respective cables to ensure you reconnect them in the original position later. LC1 → C02 LC2 → C03 LC3 → C04 LC4→ C05
- C01 is the output for the connection to the Xtrem module.
- If you have only connected one load cell, your display unit may no longer show the weight correctly and report an error. Use a multimeter to test the response of the load cell, which would be 15 mV at full load (i.e. if the load cell has a capacity of 1000 kg, the signal you measure between the +SIG and -SIG terminals should be about 15 mV).
- This signal should be proportional to the applied force. If you apply 100 kg, the measured signal is ~ 1.5 mV.
