What Calibration is and why it's important

Un-calibrated weigh systems can have many hidden costs

What is Calibration?

Calibration is the comparison between an exact known weight and the measurement reading of an instrument such as a digital indicator to ensure the instrumentation and equipment is displaying the correct weight information.

Calibration is commonly carried out by a scale technician. A report is provided to show the measurement error before and after calibration. Calibrating measurement instruments not only checks the instrument accuracy but also regulates the traceability.

Why is Calibration important?

Changes in measuring system’s accuracy happen over time and can be due to a number of reasons. The main reason accuracy degrades is due to normal wear and tear. The rate at which the accuracy degrades depends on the environment and how frequent the weighing system is used. That said, other reasons include mechanical and/or electric shock or hazardous manufacturing.

A customer once sent a load cell back under warranty and we couldn’t find a fault. It turned out they had moved an electric motor closer to their weigh system and the electric frequency threw out the accuracy providing them with false readings.

Calibration is important as there can be many hidden costs if your system is inaccurate.

You may be selling more of your product than you think. If your weigh system is reading less than the true weight, you may be giving away product free of charge costing you money. Alternatively, if your weigh system is reading more than the true weigh, you may not be giving your customer enough product. This can damage your reputation and your relationship with your customer if they feel you’re not being honest.

Legal for trade — if your weigh system calibration isn’t correct you may get in legal trouble with the Government. Some weigh systems are required to be tested frequently due to local trading laws which ensure the system calibration is accurate.

Staff and/or machines may be required to backtrack and rework once your system has been calibrated. This can not only cost extra staff time and wages but also put you behind on your timeline.

How often should a weigh system be re-calibrated?

A calibration check using a known weight should be regularly performed on your weigh system to ensure accuracy. The known weight should ideally be 30% or more of the total capacity.

You should calibrate your weigh system when the following conditions occur:

A Load Cell is replaced

The digital indicator is replaced

After any major scale or weigh system reconfiguration or changes are made to the system

After a certain period of time, this varies depending on how often the scale or weigh system is used

After a power outage

After an electric or mechanical shock such as lightning strikes or if electric wielding has been performed.