Virtually every type of scale relies on load cells. If you’re getting inaccurate readings, load cell damage could be the cause. But how do you know if a load cell is bad? Read on to learn what damages a load cell, how you can prevent it, and how to check if a load cell is bad.

Causes of Load Cell Damage

Most load cells use strain gauges to measure weight accurately. This small but powerful component is the “brain” of your scale. To prevent damage, it’s crucial to use the correct weighing system for your specific needs, considering factors like temperature, humidity, environment, and application.

Some common causes of load cell damage include:

Overloading

Overloading is the most common cause of load cell failure. Excessive weight or sudden shocks can damage internal components. To prevent overloading, ensure operators are aware of weight limits and display them clearly. Using mechanical stops or limiters can also help.

Nearby Impacts or Vibrations

Vibrations from nearby machinery or sudden impacts, such as dropping heavy objects, can damage the strain gauge and internal wiring or cause other mechanical damage. Install your weighing system in an area free from physical shocks, and consider using shock absorbers or isolation pads.

Corrosion or Chemical Damage

Harsh conditions like construction dust, moisture/humidity, and chemicals can cause load cell failure due to rust or corrosion and damage to electrical components. If this is a problem for you, be sure to purchase corrosion-resistant or weatherproof load cells and regularly perform a visual check for any damage.

Electrical Issues

Wiring damage, internal shorts, or grounding problems can cause faults in the bridge circuit and electrical connections. Regularly inspect your equipment and properly shield cables. If you suspect a serious electrical issue, you should stop using your weighing system and contact an expert like UniFide CST for service.

Extreme Temperatures

Extreme temperatures can cause the strain gauge’s resistance to change, resulting in “drift,” where the displayed weight doesn’t stay steady. It’s important to buy load cells for your conditions and consult with an expert on load cells for your temperature needs. Insulation or climate control may be a potential solution for you to explore.

Misalignment

Misalignment during installation or shifting during use can cause damage over time. Be sure to use a reliable seller experienced in installation and ensure your load cell is level and properly mounted. Misalignment can occur from wear and tear, especially in truck or hopper scales. Periodic inspections should be performed to ensure your load cell remains level.

Overuse & Aging

Load cells can degrade over time, often due to excessive, rapid use beyond their rated capacity. If you plan on using your scale equipment in a rapid cycle, be sure to select a load cell designed for high-cycle applications. Wear and tear are to be expected, so regular visual checks and service are key to extending the life of your system.

At UniFide CST, our scale experts can help you select the best load cells and scale equipment tailored to your needs. Reach out today, and our experienced team can offer durable solutions backed by comprehensive support and warranty.

Troubleshooting & Preventative Maintenance

Proper maintenance will help extend the life of your load cells, prevent breakdowns, and ensure you are receiving accurate weight data. How often you perform these suggestions varies depending on your usage and manufacturer recommendations. If you’re currently troubleshooting an issue, also consider performing these steps:

  • Visual Checks: Look for any signs of damage, such as cracks, rust, or corrosion. Make sure the scale is properly leveled and the load cells are aligned.
  • Electrical: Check wiring for any cuts, fraying, or loose connections. Tighten any loose connections to avoid signal loss. If you suspect a serious electrical issue, you should immediately stop using your weighing system and contact an electrician or other expert.
  • Environment: Protect your scale from vibration and use shock absorbers or isolation pads if necessary. Install protective enclosures if exposed to moisture, chemicals, dust, or other potentially damaging environments.

Testing Your Load Cell

Testing your load cell regularly as part of preventative maintenance is essential, but you may also need to test it if you’re troubleshooting an issue. Follow these general steps, but always refer to the manufacturer’s documentation for specific guidelines.

1. Check Load Cell Output:

  • Disconnect the load cell from the scale system.
  • Using a multimeter, measure the resistance of the strain gauges. This should be 120 ohms but can vary between 100 and 350 ohms depending on specific uses. Refer to manufacturer documentation for specific values.
  • With no load the output voltage should be close to zero.

2. Check a Known Weight:

    • Place a known weight on the load cell.
    • Measure the output voltage and compare to cell capacity. For example, if the load cell’s capacity is 100 lbs and you apply 50 lbs, the output voltage should read 50% of the maximum value.
    • Continue increasing weight gradually to check and make sure the output voltage increases as expected.

If your load cell is not working properly you may need to recalibrate, service, or replace it. While damage to the load cell can be prevented it can easily happen. UniFide CST has knowledgeable experts with decades of experience who can help you with service, repair, and selecting load cells that meet your unique needs. Contact us today!