Load cell calibration 101

Whether you use them for occasional testing or continual monitoring, load cells need to be accurate throughout their lifespan. Calibration ensures that your load cells are accurate against set standards and and functioning correctly.

What is load cells calibration?

Think of calibration as a MOT for your load cells! Calibration involves comparing the accuracy of your load cells against a recognised standard, whether national or international. It’s also an opportunity to adjust each load cell if required so that it meets the standard if its performance has slipped.

 

Why do load cells drift?

Load cells are sensitive equipment, and their accuracy can deteriorate (drift) over time due to external factors, as well as their level of use. Factors that affect deterioration rates include:

• electrical influences
• mechanical effects
• instrumentation faults
• build up of dirt or dust
• adverse operating conditions such as excessive damp and extremes of temperature (if load cell not designed for these environments)
• their level of use
• mistreatment or misuse
• ageing

 

How often should I calibrate my load cells?

This depends on various factors such as usage, age of the load cells. The ISO9000 standard requires calibration every two years, but load cells in heavy or continual usage might require calibration once a year to maintain their accuracy.

 

What are load cell calibration standards?

There are a range of standards, including:

• UKAS (formally NAMAS)
• ASTM E74
• ISO 376

Successful calibration and compliance results in the issue of Certified Calibrations Certificates. Full traceability to a National Standard is often a compliance requirement for those businesses aiming for ISO9000 status.

 

How accurate are load cells?

Correctly installed, well maintained and fully calibrated load cells should provide accuracies of around 0.03 to 1%, depending on the type of load cell used.

 

What happens if I overload my load cells?

At Richmond Industries, we build our load cells tough! For example, our 100 series Low Profile load cells can be overloaded by 150% with no loss in calibration (and 200% with no structural failure, although of course we don’t recommend you overload in the first place!)

 

Why should I compare results before and after calibration?

This is a really useful way to assess how much drift your load cells have experienced since their last calibration. It’s also a useful indication of how often you should recalibrate in the future, as it may be required every six months rather than a year.

 

Do new load cells need calibrating?

Yes, all load cells need calibrating after manufacture and before installation. This is to ensure they operate at the required standard from first use.

 

Can The Load cell Shop calibrate my load cells?

Of course! We offer a comprehensive service including:

• Calibration of new load cells and instruments
• Re-calibration of your existing load cells
• Recalibration of your current load links
• Full calibration by UKAS accredited lab
• Proof testing
• Load cell output rationalisation

 

Do you offer a load cell checking service?

We certainly do! Our experienced team can check your load cells, report any that are faulty or that need replacing. They can also suggest improvements to your load cell systems, and talk you through the advantages of wireless upgrades.

 

For all your load cell calibration needs, call us on +44 (0)1189 310 396 during office hours.