How do professionals go about choosing the right load cell for a specific application?
This is a short guide on choosing the correct load cell for your application. We will cover the basic questions when selecting a product, as well the most important factors affecting your load cell choice.
Key Factors Influencing Load Cell Accuracy
It’s important to understand how your application and the load cell will be affected by each of these factors as this will affect accuracy. This includes:
- Mechanical – Dimensions and Mounting
- Electrical – Output and Excitation
- Environmental – Temperature and Moisture
Specifications of a measurement sensor define the design capabilities and capacities, including the amount of measurement that can be used for a particular device before you exceed the limits.
The major difference in strain gages is in the manufacturing process. Varied materials are used when a load cell needs to perform optimally in a variety of temperatures, humidity levels, and elevations. Matching the correct strain gauge and a load cell to the application is critical to accuracy.
A load cell starts as a raw piece of steel, aluminium, or other metal. It is machined, gaged, wired, finished, and calibrated by experts in load cell production and quality engineers.
When shopping for a load cell it is important to know the type of force that you need to measure, the size of the application, the environment in which you will be measuring the application, the accuracy of data needed, the type of communication output that will work with your current test system or if there are extreme or hazardous conditions.
The field of force measurement has the same types of constraints as any other discipline. It has considerations of weight, size, cost, accuracy, useful life, and rated capacity. This also means considerations for extraneous forces, test profile, error specifications, temperature, altitude, pressure and environment.
Basic questions to ask:
- What are the expected loads? What is the minimum and maximum load you’ll be measuring?
- Is there any potential for higher peak loads than what you intend to measure? What are these expected peak forces? Is it tension, compression, or both?
- Will there be any off-axis loads? If so, what is their geometry? Do you want to measure them too?
- Will it be a static, dynamic or fatigue measurement?
- What is the environment in which you’ll be conducting your test? Will the load cell need to be sealed?
- How accurate do your measurements need to be? Do they need to be at the highest accuracy of ±0.02-0.05% or within ±0.5-1%?
- What additional features, accessories and instrumentation does your application require to complete a test?
- Do you need standard electrical connectors or customised options? What about additional bridges or amplifiers?
- How are you planning to collect and analyse the data output from the load cell?