Why Scales Need Calibration
Even top quality scales need routine maintenance. This will ensure you get a great performance from your scale consistently.
A key part of the routine maintenance is scale calibration which should done about once every three months. Now you may want to know why a scale needs to be calibrated after a few months of use.
For this we need to understand how the scale works. At the heart of a digital scale are load cells ate the heart of the load cells are strain gauges. A strain gauge in simple terms is a long wire placed in a zig zag pattern on an alloy base. The zig zag pattern is to enable a long wire to be mounted on a fairly small area.
When a load is placed on the scale the strain gauge gets distorted and its resistance changes. This change is in proportion to the load. The electronics of the scale can then compute the weight and display it on the indicator. Then the load is lifted off the scale and the strain gauge returns to its original shape.
However with repeated use the strain gauge does not return back to its original state exactly and some residual deformation becomes permanent. This does not mean that the scale has become damaged though. This slight variation from the original shape is what the scale is adjusted for when the calibration is done as part of the maintenance. And once a proper recalibration is done the scale will continue to give a great performance.
You can do this calibration yourself if you have a set of calibration weights required for the purpose. However if your weight measurement accuracy is critical then it is best to get it done by a professional.