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How Load Cells Can Go Bad

Load cells are electronic devices that measure the force applied to them. Interface products are made to last, in fact we have many load cells that are in-market and being used for high-accuracy testing that were manufactured decades ago. Why do they last? Quality of design, material construction, build process, calibration, and regular maintenance prolong the life of a load cell.

Like any electronic device, load cells can go bad for a few reasons. It is also important to know that load cells can be repaired. Outside of complete destructive testing, the following issues are most common for how load cell can go bad.

Overloading: Load cells have a maximum capacity, and if they are subjected to a force beyond that limit, they can get damaged. Overloading can cause the load cell to deform or break, resulting in inaccurate readings or complete failure. Preventative options are to use overload protected load cells.

Mechanical and physical damage: Load cells are sensitive devices and can be damaged by impact, vibration, or shock. Mechanical damage can cause the load cell to deform or lose its calibration, resulting in inaccurate readings. Physical damage to devices is often because the load cells are dropped or mishandled during use.

Moisture: Load cells are often used in damp or wet environments, and prolonged exposure to moisture can cause corrosion or damage to the internal circuitry. Environmental exposure to moisture can also cause electrical shorts or create a conductive path between the components, resulting in inaccurate readings or complete failure. Review submersible options if testing in these environments is common.

Temperature: Load cells can be sensitive to temperature changes, and extreme temperatures can cause damage to the internal components. Thermal expansion or contraction can cause mechanical stress, resulting in deformation or damage to the load cell. Interface offers high-temperature and low-temperature load cells options.

Electrical noise: Load cells are susceptible to electrical noise, which can cause interference in the signals and result in inaccurate readings. Electrical noise can be caused by electromagnetic interference (EMI), radio-frequency interference (RFI), or other sources of electrical interference.

Aging: Not all load cells are made the same way. Interface load cells are designed to outlast any testing use for long-periods, we are talking millions of cycles. However, some load cells can wear out over time due to repeated use, exposure to the environment, or other factors. Aging can cause a decrease in sensitivity, accuracy, or stability, resulting in inaccurate readings or complete failure. All load cells need good health checks to stay working at optimal performance.

To avoid load cell failures, it is important to use them within their rated capacity, protect them from mechanical damage, and provide adequate protection from moisture, temperature, and electrical noise. Regular maintenance and calibration services, preferably every year, can also help ensure accurate and reliable performance over time.

What is the best way to determine if a load cell is bad or not working?

There are several ways to determine if a load cell is bad or not working. Here is a reminder of five quick checks:

#1 Visual Inspection: Start by visually inspecting the load cell for any signs of physical damage, such as cracks, deformations, or loose connections. Check for any corrosion or signs of moisture, as well as any visible wear and tear.

#2 Zero Balance Testing: A zero balance test is a quick and straightforward way to check if a load cell is functioning properly. With no weight applied, the load cell should read zero. If it does not, there may be an issue with the load cell or its connections.

#3 Load Testing: Load testing involves applying a known weight to the load cell and checking the reading. If the load cell is accurate, the reading should match the known weight. If there is a significant discrepancy, the load cell may be faulty.

#4 Bridge Resistance Tests: Load cells are typically constructed with a Wheatstone bridge circuit, which can be assessed for proper resistance values. If there is a significant deviation from the expected resistance values, there may be an issue with the load cell or its connections.

#5 Temperature Tests: Load cells can be sensitive to temperature changes, and extreme temperatures can cause damage to the internal components. Evaluating the load cell at different temperatures can help to identify any issues with temperature sensitivity.

Interface provides complete evaluations of any product we manufacture, to determine if the load cell is working properly. To request services, go here.

How does calibration help load cells from going bad?

Calibration is the process of adjusting a load cell to ensure its accuracy and reliability in measuring weight or force. Regular calibration is essential for maintaining the accuracy and reliability of load cells. Interface recommends annual calibration services as a preventative measure and for good maintenance of your force measurement devices.

Calibration helps to ensure that a load cell provides accurate and consistent readings. Over time, load cells can drift from their initial calibration due to environmental factors, wear and tear, and other factors. Regular calibration ensures that any deviations from the standard are detected and corrected, preventing inaccurate readings that can lead to errors in weighing and other measurements.

Load cells that are not calibrated regularly may experience premature wear and tear due to repeated use, leading to damage or failure. Calibration helps to identify any issues early on and prevent further damage, extending the lifespan of the load cell and saving on replacement costs.

Many industries and applications have strict standards and regulations for measuring weight and force. Regular calibration helps to ensure that load cells meet these standards and regulations.

Regular calibration can help load cells from going bad in multiple ways. It can help to prevent inaccurate readings, extend the lifespan of load cells, improve efficiency, and ensure compliance with standards and regulations. Accurate measurements are critical, and calibration helps to ensure that load cells is working properly. Request a repair or calibration service online.

ADDITIONAL SERVICES

Load Cell 101 and What You Need to Know

Load Cell Sensitivity 101

Can Load Cells Be Repaired?

Services & Repair

Mechanical Installation Load Cell Troubleshooting 101

How Do Load Cells Work?

Regular Calibration Service Maintains Load Cell Accuracy

Can Load Cells Be Repaired?

Load cells are very resilient. Most are constructed with sturdy materials that can withstand long and arduous cycling and multitudes of testing projects. In fact, with proper treatment, regular calibration services and use within specifications, load cells can last many years. Even with such high quality and durability, it is important to perform regular diagnostic checks of a load cell to maintain the health of any force measurement device.

FACT: Interface has load cells that are in use today that we manufactured several decades ago. As the saying goes, Interface load cells are built to last.

A load cell can be damaged or lose accuracy. Load cells can be repaired depending on the extent of damage. Some common issues such as cable damage, electrical faults, or environmental factors can be repaired by replacing parts or recalibrating the load cell. However, more severe damage such as physical damage to the load cell itself may make it beyond repair and require replacement.

What is the most common type of damage to a load cell?

Most often, a load cell is damaged by overloading or exceeding its rated capacity. This can result in physical deformation or strain on the load cell, leading to permanent damage and reduced accuracy.

Other common causes of damage to load cells include exposure to harsh environmental conditions such as extreme temperatures, moisture, or corrosive substances, as well as electrical faults such as voltage spikes or short circuits. Additionally, mechanical stress from improper installation or handling can also cause damage to load cells.

What steps should be taken to evaluate a load cell that might be damaged?

  • Visual Inspection: Ensure that the physical installation, correct interconnection of components and the system are all intact. For example, has the load cell been dropped or have any damage to connectors or adapters? Reference the installation and operation manuals available with each product.
  • Electrical Testing: Use an Ohmmeter to check the bridge circuitry and zero balance. Evaluate the resistance and output of the load cell. If there is a notable change in resistance or output, it may indicate that the load cell is damaged. This is also a good time to check the troubleshooting guide.
  • Test Loads: Apply a range of test loads to the load cell and observe if the readings are consistent and within the expected range.
  • Calibration: If the load cell is not functioning correctly, recalibrate it using a weight calibration system or load cell calibrator to see if the readings are within the expected range.
  • Professional Evaluation: Request a thorough inspection of the device to determine the load cell can be repaired or needs to be replaced.

It is important to follow safety protocols and to use proper equipment and techniques when evaluating a load cell to avoid causing additional damage.

After a thorough physical inspection along with mechanical and electrical installation checks, it is determined that a load cell is not performing to specifications it is time to contact the manufacturer for Services & Repair to schedule a return of the product for further evaluation and potential load cell repair.

Use Cases for Frequent Calibration Services and Repair Evaluations

  • Harsh environmental conditions can cause corrosion and electrical failures
  • Loading forces that exceed the load cell rated capacity can cause shifting of the zero-load output of the load cell
  • Moment loading of the load cell can cause zero shifts and other undesirable behavior
  • High cycle rates or fatigue applications can cause premature failure

Many of these symptoms can be repaired or mitigated if they are identified early during appropriate evaluation and calibration cycles. In addition, load cells are prone to losing accuracy through normal wear and tear and ageing. There are times when loading conditions and use case environments necessitate the need for more frequent evaluation and calibration cycles. The process of calibration can include adjusting the measuring instrument to bring it in alignment with the standard specifications.

It is always recommended that users consult an application engineer or user’s manual to avoid situations where a load cell can be damaged or degrade accuracy too quickly. Interface has deeps expertise in repair and calibration, built and proven over 55 years in the business of making and calibrating load cells.

Interface provides repair evaluation and services on load cells we make and from other manufacturers. Repairs include a complete evaluation of the device prior to repair and calibration upon completion. Our standards for calibration are world-class. Our calibration labs are managed by experts in diagnostics, testing and repair with engineering and metrology grade equipment designed by the leaders in force measurement.

If you’re already a load cell user and have not had your products calibrated in some time, we recommend scheduling your calibration service online here. Load cells can provide years and years of quality data as long as they are properly taken care of. Put your trust In Interface to make that happen.

Additional Resources

Services & Repair

Mechanical Installation Load Cell Troubleshooting 101

How Do Load Cells Work?

Regular Calibration Service Maintains Load Cell Accuracy

System Level Calibration Validates Accuracy and Performance