How does a digital scale work?

A digital scale simply converts a force to a measured value, in Australia that is the metric kilogram.


Most (nearly all) scales have a load cell to convert the force into a signal that can be measured. The majority of digital load cells are just simple analogue load cells with an analogue to digital converter.

Simply the item is put onto the scale and the load cell beneath bends. On the load cell are small wire like gauges (strain gauges) glued to the surface which also bend with the load cell billet. Stretch and Contracting these wires in the strain gauge changes the resistance. This in turns changes the voltage through the strain gauge which the display (indicator) reads.

Clever but very simple.