Load cell is a transducer which converts force into a measurable electrical output. There are many varieties of force sensors now, but strain gauge load cell is the most commonly used type.Load cells are used to measure weight. They are an integral part of our daily life.
How does the load cell work?
A load cell works by converting mechanical force into digital values that the user can read and record. The inner working of a load cell differs based on the load cell that you choose. There are hydraulic load cells, pneumatic load cells, and strain gauge load cells. Strain gauge load sensors are the most commonly used among the three. Strain gauge load cells contain strain gauges within them that send up voltage irregularities when under load. The degree of voltage change is covered to digital reading as weight.
When to use the load cell?
A load cell measures mechanical force, mainly the weight of objects. Today, almost all electronic weighing scales use load cells for the measurement of weight. They are widely used because of the accuracy with which they can measure the weight. Load cells find their application in a variety of fields that demand accuracy and precision. There are different classes to load cells, class A, class B, class C & Class D, and with each class, there is a change in both accuracy and capacity.
Types of the load cell
There are different types of load cells for different applications. Commonly used ones include:
- Single point load cells: a load cell is located under a platform that is loaded with a weight from above
- Bending beam load cells: several load cells are positioned under a steel structure and are loaded with a weight from above
- Compressive force load cells: several high-capacity load cells are positioned under a steel structure that is loaded with a weight from above
- Tensile load cells: a weight is suspended from one or more load cells
Many load cells also feature special properties such as a special design or material properties. That may be important depending on the application, for example if systems need to be thoroughly cleaned every day. Some load cells can withstand this type of stress without difficulty, others cannot.
Load cells can also be categorized based on the type of signal transmission: Digital load cells have built-in electronics used to process the measurement results and present them in prepared format. For analog load cells, an additional device – a measuring amplifier – is required.
Four strain gauges are positioned on the load cells below at the point where the greatest deformation occurs when force is applied. The arrow is pointing the direction of force application.
Load cell applications
Load cells represented the first major design change in weighing technology. In today’s processing plants, electronic force sensors are preferred in most applications, although mechanical lever scales are still used if the operation is manual and the operating and maintenance personnel prefer their simplicity.