A load cell is the sensor in a scale that registers the weight. Inside the load cell is a strain gauge: a small resistor that changes as the load cell deforms.
This is how it works:
- A small electrical signal goes into the load cell, for example 10 millivolts.
- When you place weight on the scale, the load cell bends very slightly.
- As a result, the resistance increases and a smaller signal comes back, for example 5 millivolts.
- Thanks to calibration, the indicator knows which weight corresponds to that signal, for example 5 kilos.
In a scale, the load cell is often positioned between a bottom plate and a top plate. These plates do not touch each other; all the weight passes through the load cell.



















