Contributors to Load Cell Accuracy

Accurate force and torque, down to a decimal of a pound of force, is a detail that cannot be overlooked in the design of load cells. Engineers, innovators, product designers, component manufacturers, and testing professionals all depend on the accuracy of load cells for measuring force, weight and torque.

Load cells are used in the design of products to determine quality and reliability through measured frictional losses and fatigue life. They are also installed on products or systems that are already complete to enhance and modernize the design. Load cells are also used to track factors of force in real-time and over long periods to help with preventative maintenance or to collect data for future product development.

Interface load cells come in many model shapes and sizes. They are used to measure everything from forces in IV bag fluid dispensing for medical applications, to the thrust power and structural tests of rockets. If measurements are even a tiny bit off in either of these examples, either patient health is at risk or the enormous investment into a rocket engine is in jeopardy. Simply stated, failure is not an option.

Accuracy by Design

By definition, accuracy is the quality or state of being correct or precise. In test and measurement, accuracy is the difference between a solid, sturdy and quality product, and a product that becomes a liability to its user. Depending on the application, inaccurate designs or stress tests can lead to product failure or worse.

How does an engineer ensure that the tools they use to design a product are providing them with the most accurate data possible? Accuracy of is dependent on the on several key contributors to precisely measure force and torque values. It all starts with the load cell and how it is designed.

Contributing Factors of Load Cell Accuracy

There are many additional factors that contribute to poor data and bad accuracy when working with load cells. These are the primary considerations to take into account.

Creep: This term used to describe the change in load cell output occurring with time while under constant load and with all environmental conditions and other variables also remaining constant. Creep occurs because materials very slowly deform over time when under constant load.

Side and Eccentric Load: Most load cells are designed to measure force in one certain direction, which is determined by the way the load cell is mounted. Inappropriate loading will cause side and eccentric load, which risks reducing the life of load cells and distorting measurement results.

Mounting Process: This is one of the most important factors for load cell accuracy. A loadcell that is mounted off-center will significantly decrease the accuracy of the load cell because the mating process between the product you are measuring, and the load cell determines the sensors ability to perform accurate readings. Always make sure to follow the mounting instructions that come with the load cell to ensure accuracy.

Temperature: Change in temperature during the measurement process is a significant factor in determining accurate load. The temperature in the air can affect the sensitivity of the load cell and provide inaccuracies if not accounted for in defining your testing protocols and device you use to gather the measurement data.

Humidity: Similar to temperature, humidity also plays a factor in measurement accuracy in certain load cell designs. The effect humidity has on the load cell is a slower process; however, over time it can skew the data. If your environment includes high humidity levels, work with you load cell provider to ensure the correct design is selected for this environment.

Interface always includes the worst-case accuracy values on its product spec sheets, unlike others who often include average or nominal values. We feel confident that our products will never measure at the worst-case; however, it is important to be transparent about the lowest possible value. It is also true that Interface products’ worst case accuracy routinely beats our competitors’ best-case.

For almost every situation in product development and testing, there is a load cell to fit the precise need. It is advisable to work with an experience applications engineer to get the precise load cell model and capacity to meet your exact requirements.

Additional Resources

How Do Load Cells Work?

Regular Calibration Service Maintains Load Cell Accuracy

Interface White Paper Highlights Contributing Factors to Load Cell Accuracy

Specifying Accuracy Requirements When Selecting Load Cells

Interface's Essential Load Cell Field Guide - Free Copy

#loadcell #sensor #sensorsolutions #InterfaceIQ #didyouknow #loadcells #accuracy #testing #engineer #measurement #measurewhatmatters #metrology #product #producttesting #productdesign #forcemeasurement #ForceLeaders #Interface #InterfaceNewsletter