Why should I know about load cells?
Load cells are at the heart of every scale system and make modern weight data possible. Load cells come in as many types, sizes, capacities and shapes as the applications that use them, so it can be overwhelming when you first learn about load cells. However, understanding load cells is a necessary first step in understanding the capabilities of all types and models of scales. First, learn how load cells work with our short overview, then learn 10 facts about load cells – starting with load cell technology all the way to the many different applications you can use them in!
10 Facts
1. The heart of every scale.
The load cell is the most important component of the scale system. Without load cells, a scale cannot measure the change in force caused by a load or weight. The load cell is the heart of every scale.
2. Enduring origins.
Load cell technology dates back to 1843, when British physicist Charles Wheatstone created an electrical bridge circuit to measure electrical resistance. He named this new technology Wheatstone’s bridge, which is still used today as the basis for load cell strain gauges.
3. Use of resistance.
Strain gauges use the theory of resistance. A strain gauge consists of a very thin wire that is woven back and forth in a zigzag grid to increase the effective length of the wire when a force is applied. This wire has a certain resistance. When a load is applied, the wire stretches or compresses, thus increasing or decreasing its resistance – we measure the resistance to determine the weight.
4. Measurement diversity.
Load cells can measure more than just the cantilever force, or the force generated at one end of the load cell. In fact, load cells can measure resistance to vertical compression, tension and even suspended tension.
5. Three major categories.
Load cells fall into three major categories: Environmental Protection (EP), Welded Sealed (WS) and Hermetically Sealed (HS). Knowing which type of load cell you need will effectively match the load cell to your application and thus ensure the best results.
6. The importance of deflection.
Deflection is the distance a load cell bends from its original rest position. Deflection is caused by the force (load) applied to the load cell and allows the strain gauge to do its job.
7. Load cell wiring.
Load cell wiring excitation, signal, shielding and sensing color combinations can be very broad, and each manufacturer is developing their own wiring color combinations.
8. Custom scale solutions.
You can integrate load cells into pre-existing structures such as hoppers, tanks, silos and other containers to create custom scale solutions. These are excellent solutions for applications that require inventory management, recipe batching, material unloading, or prefer to integrate weighing into an established process.
9. Load cells and accuracy.
High accuracy scale systems are typically considered to have a system error of ±0.25% or less; less accurate systems will have a system error of ±.50% or greater. Since most weight indicators typically have a ±0.01% error, the primary source of scale error will be the load cell and, more importantly, the mechanical arrangement of the scale itself.
10. The right load cell for you.
The most effective way to build a high precision scale system is to select the right load cell for your application. It is not always easy to know which load cell is best for each unique application. Therefore, you should always engineer and load cell expert.
Post time: Apr-04-2023
