Structure and function of a load cell
A load cell is a precise force sensor that converts the weight of an object into an electrical signal . This signal can then be electronically evaluated, enabling precise weight or force measurements . Load cells are the core component of modern weighing systems in industry, laboratories, and commerce.
Construction of a load cell
The basic structure of a load cell consists of a mechanical spring body , usually made of aluminum , stainless steel , or steel . Strain gauges are firmly attached to this body and are usually protected by a potting compound .
As soon as a load or force acts on the load cell, the spring element deforms minimally. This microscopic deformation is detected by the strain gauges. The strain gauges are sensitive to any change in strain and change their electrical resistance proportionally to the applied force.
Function and measurement principle
The measuring principle of a load cell is based on the Wheatstone bridge , an electrical circuit that reacts to the smallest changes in resistance.
The change in resistance caused by the strain gauges generates a minimal change in voltage , which is processed by electronic amplifiers and converted into a precise measurement signal .
This signal can then be output as weight (in kilograms) or force (in newtons) . Modern weighing systems and digital measuring devices further process this data to deliver reliable measurement results – whether for filling, dosing, testing, or weighing.
Types and applications of load cells
Depending on the design and area of application, different types of load cells are distinguished:
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Bending beam load cells (bending bar load cells, single-point load cells) – measure forces via bending, frequently used in platform scales.
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Compressive load cells (pressure load cells) – high load capacity with space-saving design, ideal for vehicle, tank or silo scales.
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Shear load cells (shear beam load cells, double shear beam load cells) – Robust and insensitive to transverse forces, ideal for precise industrial applications.
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Traction load cells – measure forces that pull or hang at a point.
Thanks to their high sensitivity , long-term stability and reliability, load cells can be found in almost all industries – from the food industry to laboratory applications and automation technology .
Summary: Electromechanical sensor with precision
In short:
A load cell is an electromechanical sensor that converts mechanical deformation through strain gauges into an electrical signal . This signal is directly proportional to the applied load or force .
Whether in the weighing of raw materials, in automated production facilities or in high-precision laboratory scales – the load cell is the basis of every precise weight measurement .