The zero point output signal value of the electronic scale load cell is generally between -3mv and 2mv. If it is far beyond the range of this standard, it may be that the load cell is overloaded during use and the elastic body is plastically deformed, making the load cell unusable. If there is no zero point signal or the zero point output signal is very small, it may be caused by the strain gauge in the load cell having fallen off the elastic body or there is a support to support the scale body.
Electronic scale replacement electronic scale load cell steps are as follows:
1) Open the upper cover of the load cell (damaged), lift the weighing platform with a jack, and remove the load cell ground wire.
2) Open the junction box and disconnect the damaged load cell cable from the junction box. Pull out the cable at the load cell end. Note: When drawing the wire, attach a lead to pass through the scale body, so that when replacing a new load cell, the cable will pass through the scale body and enter the junction box.
3) Refer to the second method above, and pass the load cell cable through the scale body into the junction box.
4) According to the wiring diagram, fix each core wire of the cable to the corresponding terminal of the junction box.
5) Loosen the jack, level the weighing platform, and close the cover.
6) After replacing the load cell, the truck scale must be reset and calibrated.
7) After the load cell is installed, the excess cables should be bundled and placed, and not directly placed on the foundation ground.
8) In order to ensure the consistency and interchangeability of the load cell, the load cell cable shall not be cut off at will.
9) During installation and disassembly, no scratches or bumps on the load cell shall occur, and the cables shall be protected.
The following phenomena occur in the electronic scale, which should be suspected to be the fault of the load cell:
(1) The electronic scale does not display zero, and the display keeps flashing.
(2) After the electronic scale displays zero, the weight is added and the weighing number is not displayed.
(3) When the electronic scale is empty or loaded, the displayed number is unstable, drifts or jumps.
(4) The electronic scale weighs inaccurately, and the displayed weighing number is inconsistent with the number of added weights.
(5) The repeatability of the electronic scale is not good. If the same weight is added, sometimes the weighing is accurate, and sometimes the weighing is not accurate.
The above phenomena may be the fault of the load cell. The load cell that needs to be judged is removed from the system separately, and the input impedance and output impedance are measured separately. The normal value of input impedance is 380Ω, and the normal value of output impedance is 350Ω. If the measured data is not within this range, the load cell has been damaged. If there is an open circuit in the input impedance and output impedance, first check whether the load cell signal cable is disconnected. When the signal cable is intact, the strain gauge of the load cell is burned out, usually because a large current enters the load cell. When the measured input impedance and output impedance are unstable, it may be that the insulation layer of the signal line is broken, the insulation performance is reduced, or the load cell is damp, which makes the bridge circuit and the elastomer poorly insulated. The zero point output signal value of the load cell is generally between (-3mv~2mv). If it is far beyond the range of this standard, it may be that the load cell is overloaded during use and the elastic body is plastically deformed, making the load cell unusable. If there is no zero point signal or the zero point output signal is very small, it may be caused by the strain gauge in the load cell that has fallen off the elastic body or there is a support to support the scale body.