Load cells are a low-cost and durable solution in most weight measurement applications. These precision force measuring instruments find countless applications in industrial weighing, agriculture, and quality control fields.
These innovative instruments are typically used in weighing applications owing to the accuracy and consistency that they provide. This blog covers all the ins and outs of load cells in detail. With this information, you will be able to identify what makes different load cells unique and how you can use these in different applications so keep on reading till the end.
- What is a Load Cell?
- Design and Working of a Load Cell
- Types of a Load Cell
- Single Point Load Cell
- Beam Load Cells
- S-Type Load cells
- Shear Web Load Cells
- Single-Column Load Cell
- Multi-Column Load Cell
- Uses of Load Cells
What is a Load Cell?
A load cell is a highly sensitive and accurate mechanical transducer that can convert the force resulting from tension, pressure, compression, and torque into quantifiable output.
Load cells made from different materials utilize their specific physical properties to create measurable results. The output generated is in direct proportion to the force experienced by the load cell. The force is processed by an electronic circuit which can then be displayed or stored based on the application.
Design and Working of a Load Cell
Most load cells are used to measure weight in the inner workings of an apparatus or mechanism. These cells come with a spring usually made of steel and a strain gauge.
This spring is minimally elastic and it can detect even the smallest variations in the weight. When the weight is applied to the load cell the strain gauge experiences a force that leads to internal deformation. This deformation is the measure of the strain of the object which is then converted into an electrical signal to get the right value of weight.
Within a strain gauge, there is an electrical conductor linked with a thin film. This film can elongate or contract based on the applied force and that changes the resistance in the conductor.
Basically, it is this resistance that a load cell converts into digital readings giving you an accurate value of weight, pressure, or force.
Types of a Load Cell
Following are the main types of load cells that you normally find in most applications
1. Single Point Load Cell
Single point load cells are low-capacity compression load cells that are the most common. What makes these load cells ideal for small scales and check weighing systems is their ability to measure off-center loads with high accuracy.
These load cells are in the shape of a horizontal long beam. In these cells, the loading axis is perpendicular to the horizontal axis and the placement of strain gauge is done at the top and bottom of the beam on the outer surface.
2. Beam Load Cells
There are three main types of beam load cells i.e., Bending (Bellows) Beam, Shear Beam, and Shear Beam Double-ended.
Bending (Bellows) Beam
These are horizontal rectangular beam-shaped cells that are ideal in low-capacity vessel weighing and checkweighing applications. In these cells, the loading axis is perpendicular to the horizontal axis. The strain gauges are placed at the outer top and bottom ends to measure bending strain.
Shear Beam
These compression load cells are also horizontal beam shaped and they are ideal for mid-range capacity weighing and low-profile process applications. The loading axis in this case is also perpendicular to the horizontal axis and the force is applied to the end of the beam that is opposite to the fixed end.
In this case, the strain gauges are bonded at 45-degree angles on either side of the beam.
Shear Beam Double Ended
The previous shear beam load cell is secured at one end but in this case, both ends are fixed and secure while the load is applied right in the middle. These find applications in truck weighing, tank weighing, and other high-capacity weighing applications.
These are also horizontal beam-shaped where the loading axis is perpendicular to the horizontal axis. The load acts at the center of the beam and the strain gauges are bonded at 45-degree angles on either side of the beam.
3. S-Type Load cells
The S-Type load cells are in the shape of an S and they belong to the low to mid-capacity tension load cell category. These cells work in both tension and compression which makes them ideal in hanging scales. These load cells are fitted with eye bolts at the top and bottom which allows you to easily suspend these from shackles.
In this case, the loading axis is the geometric center and the force acts on the horizontal axis. The strain gauges are placed inside a machined-out circle in the interior so that they are parallel to one another.
4. Shear Web Load Cells
These load cells are ideal in applications where weighing needs to be done on a tapered base with an integral threaded rod installed. These load cells are relatively less sensitive to off-axis loading. Typically, these are ideal for applications ranging from 100 lbf to 100,000 lbf.
5. Single-Column Load Cell
In this type, the spring element is designed for axial loading. It comes with four strain gauges where two are in the longitudinal direction while the other two are oriented transversely.
6. Multi-Column Load Cell
In this case, the load is carried by four or more columns each having its own set of strain gauges. The gauges from each of the columns are connected in a series in the form of bridge arms. These load cells offer enhanced discrimination against off-axis loading.
Uses of Load Cells
Following are the main applications of load cells
- These are used in the food processing sector to ensure proper distribution of ingredients as well as products during manufacturing and packing.
- Industrial warehouses use these to determine the precise weight of a loaded pallet.
- These are used to test building materials like beams for structural sturdiness.
- These are used in material research and pharmaceutical labs to weigh samples and calibrate equipment.
- These are used to weigh trucks and railroad cars in the transportation and logistics industry.
Conclusion
Load cells are a key component in security systems, digital weighing scales, thermometers, and high-end applications like industrial automation and submarine pressure sensing.
These devices are responsible for measuring force or pressure applied on a surface to a quantifiable output in the form of an electrical signal. Load cells are available in different types and you need to pick one that suits your application. This can ensure you are able to get accurate weight measurements every single time.
Visit Accurate Meezan today to order our top-quality load cells to use in all industrial and general applications.