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Independent calibration of structure and load cell?

  1. Mar 11, 2015 #1

    I have a load cell which must be placed onto a piece of vehicle structure. In an ideal world I would attach the load cell to the structure and calibrate both together to ensure a very accurate calibration, and that accurate loads are measured. However a problem arises if I need to replace the load cell (i.e. due to failure), as it is impractical to calibrate the new load cell and structure together once installed on the vehicle, instead I would like to replace just the load cell. Is it possible to 'calibrate' a piece of vehicle structure so that when I attach a new calibrated load cell, I can combine the structure’s calibration data with that of the new load cell’s to obtain accurate loads?
     
  2. jcsd
  3. Mar 11, 2015 #2

    CalcNerd

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    The load cell is merely strain gage so to speak. Once loaded, and you replace the load cell, you now have to recalibrate. You cannot attach the load cell to the loaded part and get the same strain. You either have to remove the stress on the part, attach the load cell (strain gage) and put load back on unit.

    Or accept the fact that you will just recalibrate the strain gage. If you had data from the earlier load cell, you might be able to mimic the original output.
    Recalibration should not be that hard, but you will have introduced some error in comparison to the original load cell. Often this error would be small and you would measure a min value and a max value and a few points in between and hopefully it would be very linear.

    Most load cells are meant to replace previous cells, and recalibration is the only proven way to assure you have the same (or reasonable) accuracy (most industries accept 0.5% full scale).
     
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