One of the most widely used types of load cells is the strain gauge load cell. It’s a transducer that creates electrical resistance when under strain or pressure. The electrical resistance is directly proportional to the strain placed on the load cell to produce accurate measurements.
Electrical resistance from the strain gauge is linear and can be changed into a value for force or weight if needed. It’s comprised of four strain gauges in a Wheatstone bridge configuration. A Wheatstone bridge is a very simple electrical circuit that measures an unknown electrical resistance and provides incredibly accurate measurements. The strain gauges in the Wheatstone bridge are bonded onto a beam that moves or “strains” when weight is applied.
Three of the most popular strain gauge load cell types are Shear Beam load cells, S-Beam load cells, and Button load cells. Here we lay out the features of each as well as some factors you should consider when selecting the proper load cell for your application.
S-Beam Load Cells
S-Beams are a popular load cell type for general weight or force measurement applications. When pressure is applied, the middle beam of the “S” acts as a spring. It compresses or elongates proportionate to the weight applied and springs back to its original shape when the pressure is released. For this reason, the S-Beam load cell can measure both tension and weight.
These versatile load cells are available with AC or DC output and are a great choice for scales with small to medium load ranges, material fatigue testing systems, traction testing systems, or any application where tension needs to be measured.
They are commonly used in the automotive industry for performance testing on car components. These load cells help ensure your safety by making sure the hinges, latches, and handles used in your car doors, trunks, or hoods will hold up. When you need a high-performance load cell that’s cost-effective, S-beam type load cells are an excellent choice.
Shear Beam Load Cells
Compression load cells are unsuitable for dynamic applications. This means shear beams are one of the types of load cells that are commonly used in environments where stirrers or agitators are at work. When applied beneath a tank, thermal forces or lateral movements won’t sabotage its effectiveness.
Available for both AC and DC output, Shear beam load cells are great for weighing applications of medium or large capacity. From weighing tanks in factories or on vehicles to building multi-sensor scales, these types of load cells can withstand harsh environmental factors.
You’ll find these load cells being put to use in food packaging or bottling plants for applications such as platform, conveyor, or container scales. If you need to measure weight and torque, shear beam is the way to go.
Button Load Cells
Button (Round) load cells are popular load cell types for low capacity measuring applications. If you’re weighing materials from 25 to 300 pounds, these are a suitable option. They’re very cost-effective and easy to install, which is one factor for why they’re widely used.
You’ll also find analog or digital versions of these load cells testing the doors or trunk of your car and many other applications requiring weighing or quality control. These small but durable components can withstand intense heat, cold, moisture, pressure, and more.
Factors to Consider
With so many types of load cells to choose from, here are some factors to consider when making your selection.
- What are your non-linearity specs?
- What is the repeatability requirement?
- What are your hysteresis specs?
- What is your normal expected load?
- What are the maximum expected loads?
- What are the voltage requirements for your system?
- What type of connector will you be using?
- What are the size requirements for height or diameter?
- Will it need to withstand vibrations or agitation?
- Will there be pollutants such as dust, water, oil, food, chemicals, or others present?
- What will the minimum and maximum temperatures be?
- Is it a high humidity environment?
Finding Customized Solutions
Button, S-Beam, and Shear Beam load cells are so versatile and widely used. They can be utilized effectively in a variety of applications. P3 America has become an industry leader when it comes to providing top quality load cells nationwide.
Occasionally, engineers have specialized applications that require load cell types beyond the general use models. P3 America will work with you to create custom solutions for you. Browse our premium selection of load cells, and if you don’t find what you need, contact one of our knowledgeable team members for a free consultation.