When A Load Is Applied, The Body Of The Load Cell Will Bend Due

• Posted by liheng huzhou April 23, 2021 - Filed in Business - #weighing transducer，bending beam load cell  - 753 views

  　　Work criteria

  　　Like all other modern weighing transducers, beam load cells are essentially sensors that convert force or weight into electrical signals through strain gauges. When a load is applied, the body of the load cell will bend due to the elasticity of the metal material it is made of. Strain gauges strategically positioned and fixed on the surface of the load cell will also stretch or compress along the body. This changes its resistance and causes the voltage across the circuit to change. This effect is proportional to the initial force or weight, so it can be calculated.

  　　design

  　　The shear beam load cell has a variety of shapes and sizes, which can be adapted to a wide range of applications. Generally, they all have a relatively low vertical profile relative to their length. This is in contrast to certain cylindrical compression load cells, which usually have the opposite ratio and are narrower than their height.

  　　The design of the shear beam load cell should make certain parts of the load cell body bend or bend in response to the applied load. They tend to provide large amounts of strain or deflection under relatively small forces, which makes them suitable for low-volume applications.

  　　A strain gauge placed on a convex surface will stretch, while a strain gauge placed on a concave surface will shrink. This means that there are always two surfaces subject to the same and opposite strain, which is very convenient for implementing a full-bridge circuit or for temperature compensation.

  　　Although the shear beam load cell looks similar at first glance, the working principle is different. A groove is machined on each side of the load cell, and a relatively thin vertical web is left in the middle. This makes the cross-sectional appearance of the load cell resemble the structural I-beam seen in the structure, and like them, most of the shear strain is concentrated on this thin vertical web. Strain gauges are installed on the side of the web at an angle of 45 degrees to detect strain. At the same time, the top and bottom flanges help resist any moment or bending.

  　　The shear beam load cell has become very popular in medium and high volume applications, with excellent lateral force resistance. Due to the difficulty of making the webs thin enough to obtain the necessary strain level, they generally cannot be made into low-volume products. Bent beams and single-point load cells will be more suitable for such use cases.