Dictionary says that a load cell is a weight measurement equipment needed for electronic scales that tend to display weight in digits. But load cells aren’t limited to the weight measurement when it comes to electronic scales. They are also known as load transducers. Load cell displays tend to implement many operating principles, namely:
- Load cells on the basis of fluid pressure
- Load cells on the basis of electricity
- Load cells on the basis of magnetostriction effect or the piezoelectric effect
But only the prevalent load cells are on the basis of the strain gauges. This is why load cells mean strain gauge based load cells. This is because of the famous adoption of the strain gauge based load cells and their features:
- Superbly precise and linear measurement
- Tiny influence because of temperature changes
- Tiny in size as compared with other kinds of load cells
- Long operating because of lack of moving parts or components that generate friction
- Ease in production because of small amount of parts
- Superb fatigue features.
Measurement Principles
- Spring material
The spring or the sensing element is the primary structural part of the load cell. The design of the element has a strain which is directly proportional to the load applied. When an external force is applied, the molecular force functions between the molecules that constitute the object and generating an internal force that avoids the deformation by the applied force. When the external and internal forces are balanced, the deformation stops. In this case, the internal force per unit area on the cross section of the object known as the stress and the variation in dimensions per unit is known as the strain. To improvise the load cell performance, the features of spring material are essential. To know more about Load Cell Signal Conditioning, get in touch with us today.
- Strain gauge
As resistance is determined on the basis of length, resistivity and cross sectional area of the material, the same wire will have different resistance on the basis of its elongation or contraction. The longer the string, the larger the resistance. The strain gauge uses this principle and is referred to as equipment whose resistance changes in proportion to the strain amount in the device. The metallic strain gauge entails a fine wire or a metallic foil arranged in a grid pattern. The cross sectional reduces the effect of shear strain and Poisson Strain.