Understanding Winter Temperature’s Effects on Load Cells and Weigh Systems

Winter’s temperature extremes and fluctuations can present multiple challenges to your weighing equipment’s proper function. From material expansion and contraction to conductivity changes, temperature effects on strain gauge load cells can seriously alter measurement system accuracy and reliability. This article explores these temperature effects and what you can do to mitigate potential issues.

Why Temperature Matters to Load Cells

Temperature extremes affect strain gauge load cells, in a nutshell, because they are made of metal. In cold temperatures, most metals have reduced ductility and increased conductivity. They also contract, altering a metal element’s shape. Since strain load cells leverage all three of these attributes of metal (load cell body’s shape and ductility and the strain gauge’s ductility and conductivity), temperature will clearly affect their performance. Moreover, cold temperatures can cause condensation on the load cell surface. This can cause moisture intrusion in lower-quality load cells.

Both the extreme cold and rapid temperature changes of winter can affect a load cell’s accuracy and durability. This, in turn, impacts the consistency and efficiency of any manufacturing process that relies on them. Quality load cells, such as those we carry by ANYLOAD, incorporate circuitry that compensates for temperature swings. However, outside of their rated temperature (most are rated for -10⁰ C to +40⁰ C / 14⁰ F to +104⁰ F), even quality load cells may begin to experience issues. As climates experience increasing temperature extremes, some outdoor systems may easily be exposed to heat or cold outside these limits.

Common Temperature-Related Load Cell Performance Issues

When load cells undergo exposure to cold winter temperatures while in service, their output may get “wonky” in the following ways.

• Zero Drift: Zero drift occurs when the load cell’s zero balance shifts. In colder environments, each of a load cell’s internal strain gauges may respond slightly differently from each other in terms of ductility and conductivity, altering the zero point and leading to inaccurate measurements.
  
• Output Sensitivity Variations: Recall that load cell sensitivity is defined as its millivolt output per volt of excitation at its maximum rated load. This value on its datasheet shows its tested output when calibrated within specific temperature ranges. Outside these ranges, the relationship between the force applied and the output signal may change due to changes in sensitivity, causing unreliable measurements.
  
• Increased Noise: Temperature changes can introduce or exaggerate electrical noise, affecting output signal conditioning results.
  
• Mechanical Stress: Sudden temperature shifts can cause materials within the load cell body to contract or expand unevenly. Over time, this can lead to physical stress and, ultimately, premature failure. Note that this is an issue not only when the load cell is in service, but also when it is stored improperly.

Design Features to Combat Temperature Effects

High-quality load cells, like those from ANYLOAD, have design features that minimize temperature-related issues.

• Temperature compensation: Modern load cells often include built-in temperature compensation circuits.
  
• Robust materials: Load cells made from stainless steel or other thermally stable materials are less susceptible to expansion and contraction.
  
• Sealed enclosures: IP-rated enclosures protect against condensation and environmental moisture, common in cold or humid environments.

Load Cell Best Practices for Winter Operations

Even with advanced load cells, taking proactive steps can improve performance during the winter months. These steps include looking at the whole weighing system, not just the load cells themselves.

1. Monitor Temperature Ranges: Ensure the operating environment stays within the load cell’s specified temperature range. If your facility experiences extreme cold, consider adding insulation or localized heating to protect sensitive equipment.
   
2. Calibrate Regularly: Winter is a good time to recalibrate your load cells. Calibration compensates for any shifts caused by temperature changes, ensuring accurate readings.
   
3. Inspect and Maintain the Entire System:
   • Check for signs of condensation or frost.
   • Ensure that all cables and connections are secure and free from moisture.
   • Look for any physical damage to load cells or mounting systems that might have been exacerbated by temperature-related stress.
     
4. Use Suitable Mounting Hardware: Proper mounting reduces the impact of uneven thermal expansion. Materials with similar thermal coefficients as the load cell can help maintain alignment and performance.
   
5. Consider Environmental Shields: Use protective covers or enclosures to shield load cells from direct exposure to cold air, snow, or ice. This can also reduce temperature fluctuations.

Troubleshoot Cold-Related Load Cell Issues

If your weighing system exhibits irregularities this winter, here are some steps to identify and address the problem:

1. Check Calibration: Perform a test weight verification to ensure your load cell is still within acceptable tolerances.
   
2. Inspect Connections: Loose or corroded connections can introduce errors. Verify that all connections are tight and free from moisture.
   
3. Review Temperature Logs: If your facility tracks environmental conditions, compare temperature fluctuations with periods of erratic readings to determine if there’s a correlation. Even if the readings seem steady, make sure they are within acceptable differences to past ones during similar environmental conditions.
   
4. Consult the Manufacturer or Distributor: If problems persist, contact us or the manufacturer for guidance. High-quality suppliers like ANYLOAD offer technical support to help diagnose and resolve issues.

Conclusion

Temperature fluctuations, particularly during the winter months, can pose challenges for load cells in weighing systems with climate exposure. However, understanding the effects of temperature and taking proactive steps can help maintain accuracy and reliability. By investing in quality equipment, implementing best practices, and performing regular maintenance, you can ensure your weighing systems continue to perform optimally for their expected lifespans—no matter the weather.

If you have questions about winterizing your load cells or need assistance with selecting the right equipment, our team is here to help. Feel free to contact us for expert advice tailored to your situation.