By definition a load cell is an electronic device (a transducer) that is used to convert a force into an electrical signal. What does this mean? A load cell is a transducer which converts force into a measurable electrical output.
How does this work? The conversion of the force into an electrical current is indirect and happens in two phases. A load cell can consist of one, two or four strain gauges depending on the type of cell, and it is the strain gauge that converts the force into the electrical current. Now not all cells use strain gauges, there are many different types such as hydraulic, pneumatic, fibre optic, button and washer load cells to name a few.
What can you do with the electrical output? Well before the electrical current can be used the electrical signal output usually requires amplification by an instrumentation amplifier and then it can be used. Load cells are primarily used as a weighing apparatus. The strain gage-based load cell has become the method of choice for industrial weighing applications.
Which applications use load cells? To name a few they can be found in electronic crane scales, finding the center of gravity of an object by weight, force measurement, force gauge, onboard weighing, railcar weighing, structural health monitoring, and tension measurement.
Examples of Digital Load Cells and Their Applications
There is a massive variety of cells today, all of which are better used in certain applications and circumstance than others for example the new compression load cell is used for applications in tough environments. The new beam load cell is great for belt scales, platform scales, filling machines, and process equipment. The single point load cells are usually found in applications such as multihead weighers, checkweighers, filling machines, belt scales, platform scales, and bench scales. Depending on your requirements and the type of weighing you are conducting will depend on the type of cell you should use.