>When the International Committee for Weights and Measures announced that it would reconsider the kilogram definition, it said it would require three measurements with uncertainties below 50 parts per billion, and one below 20 ppb. But with the new NIST measurement, the world now has at least three experiments below 20 ppb — another was conducted by a Canadian team using a Kibble balance, the third by an international group that calculates the Planck constant based on the number of atoms in a sphere of pure silicon.
>The weights and measures committee will meet this month to establish a global value for Planck's constant by averaging the values calculated at NIST and other labs. And in 2018, at the next General Conference on Weights and Measures, the scientific community will draft a resolution to redefine kilogram based on this constant.
Looks like the current title "NIST to redefine the kilogram based on a fundamental universal constant" is confusing because it implies that NIST defines kilogram but it's International Committee's for Weights and Measures job.
>The weights and measures committee will meet this month to establish a global value for Planck's constant by averaging the values calculated at NIST and other labs. And in 2018, at the next General Conference on Weights and Measures, the scientific community will draft a resolution to redefine kilogram based on this constant.
Looks like the current title "NIST to redefine the kilogram based on a fundamental universal constant" is confusing because it implies that NIST defines kilogram but it's International Committee's for Weights and Measures job.