What is the perfect Kilogram- And how do we know your scales are correct?

Who Checks the Checkers? How the UK chases the perfect Kilogram and how it can help you with your scale calibration.

Last week on site with a customer, one of our engineers was asked a very routine question, “How do you know your weights are correct?” Our engineer let them know our test weights are traceable to UKAS standard by a UKAS laboratory. However it was really the follow up question that had my engineer puzzled “But how do they know their weights are right?” A simple question with a somewhat complicated answer.

Take a deep dive on how your weight on your scales can lead a trail all the way to a metal cylinder in a vault in the French capital.

1. You have your scales calibrated by one of our calibration engineers with a 1kg Stainless steel weight - We issue your certificate of calibration and send you a Digital Copy.
2. Then once per year, our test weights are calibrated at a UKAS accredited weight calibration center.
3. The UKAS Laboratory checks their weights against standard held by the National Physical Laboratory in London England
4. The National Physics Laboratory is then in turn traceable to the international prototype Kilogram, which was a 1kg SS weight buried deep in a vault underneath the French Capital, Called ‘Le Grand K’ Which in 2019 was the standard for Weights and Measures- however this has since changed.

Moving away from ‘Le Grand K’ The Kilo that changed the world.

Le Grand K was a great movement for the world of weights and measures, however it was fundamentally flawed: It gathered dust and changed mass over time ever so slightly due to natural wear.

So how did the world solve this?

The Planck Constant, A rather uninspiring name compared to Le Grand K, However a very intriguing equation which defines the very smallest amount of mass found and everything is now derived as a multiple of that amount creating a constant measure of weights without need for the use of a metal cylinder.

So how can this help you?

The story of ‘Le Grand K’ ‘Planck's constant’ outlines a very substantial need for traceability, so make sure you have your scales calibrated by an accredited party- such as the team here at Oakleyweigh and make sure they are as accurate as possible Get in contact via the link below to make sure your scales are as accurate as possible.

https://www.oakleyweigh.co.uk/scale-calibration