Learn the common causes of load cell problems in industrial weighing technologies, and how WIKA engineers can customize sensors — even in small quantities — to reduce the chances of load cell failure.
Load cells and other industrial force transducers are sensitive yet robust measuring instruments. However, they will fail under certain conditions.
What is the main cause of load cell failures?
Most load cell problems occur due to operator misuse, namely overloading. End users might drop a load onto the weighing platform, which subjects the load cell to dynamic forces that exceed its designed parameters. Or they might not center the load properly; this creates side loads and off-axis loading that can lead to inaccuracy and physical deformation of the sensor.
SOLUTION: Because human errors are inevitable, system engineers and equipment manufacturers should always factor that in when choosing load cells. The right load cells should have:
- A sufficiently high force range for an application
- Built-in buffers for safe overload and ultimate overload
Safe overload is the range over the rated capacity where the load cell can function outside of accuracy specifications without suffering permanent damage. Ultimate overload is the maximum force that can be applied to a load cell; above this percentage, the load cell is very likely to experience structural failure.
Once a load cell begins to suffer from accuracy issues, that usually means its strain gauges have been damaged. Sometimes it’s possible to replace just the strain gauges and recalibrate the sensor. But for the greatest reliability and accuracy, our recommendation is to replace the entire load cell.
WIKA load cells are typically designed with a safe overload up to 150% and an ultimate overload of 150% to 300%. Determining the overload is a balance between output and the size of the load cell.
What are some other causes of load cell failure?
Besides overloading, common reasons for load cell problems include
- Electrical damage — faulty wiring, overvoltage, power surges, lighting strike (if outdoors)
- Cut cable or damaged connectors — usually from mishandling or human error
- Moisture ingress
- Temperature damages — operating outside the specified temperature range
Customizing to Avoid Load Cell Problems
Load cells can be customized in several ways to optimize their service life:
WIKA force sensors are available with approvals in accordance with ATEX, FM, CSA, UL, IECEx, and PL.
- Force ranges — operational (working range), safe overload (force limit), and ultimate overload (breaking force)
- Size and shape — should be engineered for the specific weighing technology and application
- Mounting hardware — threads, base plates, load buttons, keeper plates, bearings
- Electrical connections — connectors and cable type
Most sensor manufacturers require a high minimum quantity for customized load cells. WIKA does not. By leveraging our global supply chain and facilities across three continents, including North America, we are able to offer our customers virtually any quantity, including a single engineered load cell.
Standard and Custom Load Cells by WIKA
Located in central Ohio, WIKA Sensor Technology designs and manufactures robust force sensors and high-tech pressure instruments in a AS9100-certified facility. Contact us for expert advisory on how to select the optimal load cells for your specific applications.