On May 20, the kilogram joined other standard units of measure such as the second, metre, ampere, Kelvin, mole and candela that would no longer be defined by physical objects. The kilogram now hinges on the definition of the Planck Constant, a constant of nature that relates to how matter releases energy. “A Kibble Balance capable of measuring at least a kilogram takes about ₹50 crore to manufacture. The NPL itself will be relying on the kilogram maintained in the U.S.-based National Institutes of Standards and Technology to calibrate its one-kilogram weight. “With our own Kibble Balance capable of measuring a kilogram, we can be fully independent,” Dr. Aswal said.

Source: The Hindu May 20, 2019 14:54 UTC