How to Ensure You Have Calibrated Weighing Scales

Whatever the application, calibrated weighing scales are essential if you want to weigh accurately.

All scales supplied by Inscale come calibrated and ready to use (with some minor assembly for the larger scales!) so there’s no need to worry about calibration ‘straight from the box.’ But a year or more down the line – will they need re-calibrating? How do you ensure you have correctly calibrated weighing scales? In this blog post, we explain all. 

What is weighing scale calibration?

Weighing scale calibration is the relationship between the weight placed on a scale and the measurement that appears on the display. If the scale does not display the correct weight reading, adjustments may be required to ensure the scale is within ‘tolerance’ (the minimum accuracy required for the scale to be able to reliable show the correct weight reading on the display).

Why is it important to have calibrated scales?

There are a number of very important benefits to having correctly calibrated weighing scales. The first benefit is the fact that your scale will be providing an accurate, reliable weight reading.

The second benefit is that in most cases it will be cheaper to ensure your existing scales are calibrated than buying brand new weighing scales.

The third benefit is that, should you be using your scale for buying or selling, if it is correctly calibrated you will be providing value for money to customers (if you’re selling), or getting what you are paying for (if you’re buying).

The fourth – and possibly the most critical benefit for some – is that, for trade approved applications, an incorrectly calibrated scale could result in, at best, complaints and, at worst, fines or even lawsuits. Trading Standards representative could visit your premises at any time and check the accuracy of your weighing scales.

For peace of mind, we’d always recommend having calibration certificates for your weighing scales – these show when the last calibration check was performed on a scale, and the results.

How are weighing scales calibrated?

Weighing scales are typically calibrated using calibration weights. These are placed on the scale and the display checked to see if the reading is correct (some balances have internal calibration – you can read more about internal calibration here.

The calibration process will usually involve a number of calibration weights being added to the scale in succession until its capacity is reached, with the display being checked to ensure that the weight reading is correct. These weights will then be removed from the scale in turn to ensure that the scale shows the correct value throughout the weighing range from capacity down to zero. The result from this process is known as linearity: if you drew a graph of the results, you should have a straight line from zero to capacity and back again.

Repeatability (checking the scale’s consistency in showing readings) is also tested, by repeatedly adding the same weight to the scale and removing it.

How can I ensure I have calibrated weighing scales?

Putting scales and balances with internal calibration to one side, there are two ways you can test your weighing scales: by using calibration weights, or by requesting a qualified engineer.

Whilst checking calibration yourself is useful, it may not be possible to make adjustments to accuracy, and for this reason we recommend having your scales serviced by a qualified engineer. They will be able to perform a calibration check, make any adjustments, and also make any other repairs to your scale that may be needed.

How often should a calibration check be performed?

How often your scales are checked for accuracy will depend on how frequently they’re used, and what they are used for, but we generally recommend that a calibration check is carried out at least once a year.

It’s worth bearing in mind that, although brands like Adam Equipment and Kern manufacture weighing scales to last many years, accuracy can decline over time – and therefore, regular calibration checks will prevent you from getting inaccurate results.

How can I find out more?

Given the importance of ensuring you have calibrated scales, we’re more than happy to provide help and advice.

All weighing scales on this website are despatched fully calibrated for immediate use; if your scales are a year old or more, and you’re unsure about how to check if they are still accurate, or how to correct them if you know they’re not accurate, Get In Touch with us.