Kilogram
New Zealand metrologists prepare to redefine the kilogram
22 May 2018
The kilogram is getting an overhaul. 'The Big K' is a lump of metal kept away under glass in Paris that has defined the measurement for more than a hundred years. Audio
When is a kg not a kg?
4 Feb 2017
The measurement of a kilogram is currently based on a hunk of metal kept under lock and key in France - but that's about to change. We find out why. Audio
'Le Grand K' not so grand anymore
21 Oct 2015
The definition of a kilogram is likely to change as years of research across the world comes to fruition. Audio
Perfect Kilo
15 Oct 2011
The official kilogram weight - a lump of metal carefully stored under a bell jar in a Parisian vault - is getting lighter. So scientists are working on new ways to define it. Jonathon Keats has… Audio