Should I choose separate load cells or a complete weighing scale?

The weighing indicator is the display of the scale, but also its "brain". A scale works with load cells and an indicator. The indicator reads the signal from the load cells and uses it to calculate the weight, which then appears on the display.

To do this correctly, the indicator is calibrated using certified weights. This way, the indicator knows exactly which signal corresponds to which weight.

In a complete scale, the indicator is already built in or connected. A separate indicator is mainly of interest if you are building a weighing system yourself, for example with separate load cells under a silo or tank. Together with the load cells, the indicator then forms a complete weighing system.

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.