The spring elements attached to a strain gauge material (usually foil meshes or semiconductors) will most commonly be made from either steel or aluminium, giving them the property of being very strong but also very slightly elastic. They will therefore deform to some extent under sufficient pressure, be it a downward force from above (compression) or a pulling force from below (tension), before returning to their original form and shape.
The strain gauges are able to measure the exact extent of this deformation in the spring elements to an extremely precise degree. In a typical load cell, it’s this micro deformation analysis that is then converted electronically into a highly accurate weight readout. Directional pressure thus creates an electrical signal in a load cell transducer, and the magnitude of this signal is directly proportional to the force being measured.
In operation, load cells are generally subject to a range of outside influences that must be carefully controlled, monitored and adjusted for. These include overall temperatures - which can affect the structure (and therefore the electrical resistance) of any material - as well as a broad array of other environmental challenges, including inclement weather, moisture and dust ingress, and changes in ambient conditions from one location to another.
Another factor to consider when purchasing these components is the type of load cell housing material they’re built from, with certain varieties being better suited to specific application environments. Common load cell housing materials include:
- Aluminium load cells
- Nickel plated load cells
- Polyethylene plated load cells
- Stainless steel load cells