The last remaining prototype

Measurements haven't always been standardised. The original inch was the width of a man's thumb, a yard was the length of his belt, and a foot was also aptly named.

Over time, measurements have become regulated and today, the kilogram is the only unit determined by a physical prototype. This might not be the case for much longer either, because metrologists have noticed that the original kilogram – a metal cylinder kept in France – has been getting lighter since the 1980s. We explore the importance of standardised measurements here, and why you need customised, accurate solutions for your business.

What could be affected by inaccurate units of measure?

The race to replace an international prototype

The prototype for the kilogram is made of platinum-iridium and kept under lock and key in Sèvres, France. When replicas from around the world were sent to Sèvres for verification, metrologists found they were all slightly heavier than 1 kilogram, which meant that the prototype had likely lost mass.

It's unclear why 'Le Grand K' – as metrologists call it – is losing mass, but scientists are seeking a way to replace the cylinder, and have come close with a solution that measures the kilogram in relation to the Planck constant and other verified units, or by counting the atoms in a 1 kg silicon ball. The new standard will be settled at the 2018 General Conference on Weights and Measures.

Why international standards are essential

Le Grand K is just 50 micrograms lighter than it is meant to be, which is smaller than the mass of a single particle of dust. This might seem marginal, but consider how many units are underpinned by the kilogram, including the microgram, milligram, gram and tonne.

Accurate measures are essential for safety, industry and trade. Medicine dosages, for example, are measured in milligrams and micrograms. Even the slightest variation could have major ramifications on a drug's effectiveness.

When it comes to trade, accuracy is essential in ensuring that customers are truly getting what they pay for. Before measures were standardised, trade was a free for all, with no way of determining whether a manufacturer was being truthful. It's not just food labelling either. Extremely valuable items, such as jewels are measured using metric units based on the kilogram.

At SRO, we know the importance of accurate measurement. Everything from computer systems to transportation rely on precise measurements, and we have been a leader in instrumentation across several industries since 1988. The only way you can ensure accurate instrumentation is to buy from a trusted provider and have your tools calibrated and serviced regularly by a licensed technician. See how our expert team can ensure the quality of your work today.