About 20 or so years ago, maybe more, I read that NIST was working of an electrical standard for MASS using a giant coil as an electro-magnet.....
I wonder if they ever succeeded?...................
In order to redefine the kilogram, a change that will be implimented on May 20, 2019, the General Conference on Weights and Measures required at least three experiments to calculate the Planck constant to an uncertainty of no more than 50 parts per billion, one of which must calculate the value to within an uncertainty of 20 parts per billion.
The international silicon sphere effort has become precise enough to achieve an uncertainty of only 10 parts per billion, and four Kibble balance measurements also produced values within the required uncertainty.
And as a result of all these measures, much more than the kilogram is about to change.
The New International System of Units
More than redefining the kilogram, the 26th meeting of the General Conference on Weights and Measures (CGPM) is setting a fixed value for the Planck constant, and as a result, enacting the largest transformation of the International System of Units since its inception in 1960.
Previously, Planck’s constant was measured incessantly, averaged with other measurements across the world, and a list of new values was delivered to research institutions every few years.
“No one will measure the Planck constant once this [vote] has passed, because its value will have been defined,” Davis says.
In addition to the Planck constant, the Avogadro constant will be set at a fixed value, as will the elementary charge (e, the charge of one proton), and the triple point of water (the temperature at which water can exist as a solid, liquid or gas, to be defined as 273.16 degrees Kelvin, or 0.01 degrees C).
By setting the Planck constant as an absolute value, scientists are turning away from conventional mechanical measurements and adopting a suite of quantum electrical measurements to define our fundamental units. Once the constant is defined, it can be used to calculate a range of masses from the atomic level to the cosmic, leaving behind the need to scale the IPK down into smaller measurable parts, or up to enormous masses.