Taking the first steps of what would be a major historical advance in the science of measurement, the U.S. National Institute of Standards and Technology is participating in a worldwide effort to ...

All change: work on the redefinition of the kilogram was carried out using a Kibble balance. (Courtesy: BIPM) The redefinition of four units of the International System of Units (SI) will come into ...

Single-electron flow measured in bid to overhaul SI base unit. You have full access to this article via your institution. Physicists have tracked electrons crossing a ...

Weighty matters: a platinum-iridium kilogram belonging to the US National Institute of standards and Technology. (Courtesy: J.L. Lee/NIST) Metrologists and policy-makers from 60 countries around the ...