Load Cell Accuracy: 5 Factors Affecting Load Cell Precision
Efficiently determining load cell accuracy is a surprisingly accessible task for anyone. However, each cell model has a different specification and default for various measurements.
Finding the best one for you is important to ensure that regular weighing is efficient. You must also note when your cells first show signs of having difficulty with weighing accurately so that you can troubleshoot, make repairs, or order replacements as necessary.
Fortunately, with Arlyn Scales, you aren’t alone. With this guide, we’ll help you understand load cell accuracy and the factors that affect it, which empowers you to determine precision and find resolution of your load cell.
What is Load Cell Accuracy?
Load cells are used to measure weight or force. They are very accurate and can measure weight down to the milligram.
Load cell accuracy is affected by a variety of factors, including the type of cell, the environmental conditions, and the installation. In order to ensure accurate measurements, we have to consider how these cells measure input.
How Do Load Cells Work
Generally, when a force is applied to a load cell, the metal of the cell changes shape as a result. The strain gauges on the load cell will change in resistance, creating a signal that converts into a unit of measurement.
This is either mass or weight. Even so, sometimes obstacles and circumstances interfere with the signal, reducing potential accuracy.
Five Factors that Affect Load Cell Accuracy
While people can calculate accurate load cell output in theory, in real life there have to be accommodations for error. Due to the strain gauges being extremely sensitive, they can easily be damaged or skew the results.
Some basic factors include the weight indicator and how it is used, the environment in question, and the other control systems within the same area. Temperature extremes and damp environments, for example, can cause damage to the load cell if not monitored.
The interaction can interfere with the signal, especially if radio or electromagnetic waves are close in range. That’s why you need to properly ground and shield your load cells.
1. Load Cell Repeatability
Repeatability means that you consistently receive the same output when the same item is weighed on a regular basis. This is of particular importance for check weighing, which involves moving weights along an assembly line, such as with mail and luggage.
2. Percent of Rated Output (%RO)
The Percent of Rated Output indicates the margin of error, or variance. For example, if you have a 10,000-kilogram scale and the %RO is .10%, then the ideal resolution would be +/-10 kilograms.
3. Identify The Temperature Range As Well.
Some scale series, like our new Arlynguard S, are designed to handle extreme heat and cold in a variety of environments. When load cells aren’t built to endure, it can become a problem as mass expands when exposed to heat, and contracts as it cools.
In the case of water, it expands when cold, so the temperature affects water droplets as well. There is a temperature effect on output, which causes various fluctuations. The same goes for temperature condensation ranges, in which the cell is maintained.
When you work in temperature extremes, the condensation range can help you calculate the margin of error due to fluctuations from heat or cold. You can use it to measure the shifts in the load cell’s sensitivity as well as the amount of zero shift during weighing.
4. Load Cell Creep
If you are weighing the same item continuously over a long time, factor in potential load cell creep. Load cell creep is when output fluctuations happen as the same load is applied to a strain gauge over a long amount of time.
The intervals, in this case, are thirty minutes, and the creep errors are represented by percentages FSO. You can use the percentages of the error to calculate the correct amount.
This isn’t as important when you remove the items and loads immediately. However, it is if the items are weighed for more than thirty minutes.
5. Output & Input Voltage
Many load cell signals involve electrical currents that come through cables. Excitation fluctuation may vary, and this will also affect the readings from the cell. A proper load cell that matches the voltage should have a more consistent output.
Find Your Full-Scale Load Cells At Arlyn Scales
At Arlyn Scales, we believe that all weighing equipment should have precision and accuracy for regular business operations. You can trust us to ensure that each product is top-of-the-line and designed for your specific business need.
Our engineers have redesigned strain gauges so that load cells can handle potential shock overload. With our diverse catalog and advanced manufacturing, you’re empowered to decide which in our newest series is right for you, with the proper temperature range or the hazards involved in the workplace.
Best of all, we can help regardless of the load specifications involved or the loads applied to the weighing systems. To find out more about our load cells and how to determine their accuracy, reach out to our team today.