A load cell refers to a transducer that transforms a force into an electrical output that can be measured. There are several force sensors available in load cell systems and the strain gauge load cells are the most commonly used type. Apart from many labs where precision mechanical balances are still in use, strain gauge load cells tend to dominate the weighing industry. Sometimes pneumatic load cells are also used where intrinsic safety and hygiene are a must. They are also ideal for remote locations as they don’t need a power supply. Strain gauge load cells are most commonly used because they provide accuracies from within 0.03 percent to 0.25 percent full scale and are ideal for almost every industrial application.
How does it work?
A load cell transforms the mechanical force into digital values where it can be read and recorded by a user. The inner functioning of a load cell may vary based on the load cell you prefer. There are many variants of load cells like button load cells, pneumatic load cells, hydraulic load cells, and strain gauge load cells. The strain gauge load sensors are the most commonly used of all. It comes equipped with strain gauges within them that send the voltage instabilities when it is under load. The degree of voltage variation is then recorded as digital reading as weight.
Load cell measures mechanical force and mainly the weight of the objects. Nowadays, all electronic weighing scales make the use of load cells for measuring the weight. They are most commonly used due to the accuracy it provides when measuring the weight of the subject. Load cells are used in many applications that need accuracy and precision. There are many classes to the load cells too, like Class A, B, C, and D, and each class comes along the variation in accuracy as well as capacity.
Types of Load Cells
- Hydraulic load cells
They are force balance devices that measure weight as a change in pressure of the filling fluid. When a load or force acts on a loading head, it is transferred to a piston that compresses a filling fluid kept in an elastomeric diaphragm chamber.
- Pneumatic load cells
They also work on force balance principle. They use multiple dampener chambers for higher accuracy than a hydraulic device. They measure small weights in industries where cleanliness and safety is a must.
- Strain gauge load cells
This is where strain gauge assembly is placed inside the load cell housing for transforming the load into electrical signals. The weight is measured by voltage fluctuation caused when it goes deformation.