What is a Loadcell?

A Loadcell is a transducer that converts a physical force applied to it (weight, compression, tension) into a measurable electrical signal. It is considered the "electronic scale" of modern industry.

Working Principle: Strain Gauge

Inside a loadcell, there are thin conductive wires called Strain Gauges bonded to a metal body. When force is applied, the metal body flexes at a microscopic level. This flexing causes the wires on the Strain Gauge to stretch or compress, changing their electrical resistance.

This change in resistance is converted into a very small voltage difference (usually at the mV level) via a Wheatstone Bridge circuit.

mV/V Output: Loadcells typically output a signal proportional to the excitation voltage (e.g., 2mV/V). This means a loadcell at full capacity powered by 10V will output 20mV.

Industrial Applications

Tank and Silo weighing
Truck scales
Filling and packaging machines
Material testing devices

These sensitive mV-level signals must be processed by specialized devices like the GDT Digital Transmitter and converted into digital data or 4-20mA signals that PLCs can understand.