the kilogram, the ampere, the kelvin and the mole

New definition of kg and K, and its realization.

Picture description:

New definition of Kilogram is defined as the Plank constant, h. The realization of it is the X-ray-crystal-density(XRCD) method. The mass of the Si-sphere is determined by counting the number of atoms in a Si28-enriched sphere.

New definition of Kelvin is defined as the Boltzmann constant, k. The realization of it is the acoustic gas thermometry method. The thermodymanic temperature T is determined by measuring the speed of sound and combing with the average atomic mass in a monatomic gas inside an acoustic resonant chamber.

 

 New definition of A and mole, and its realization.

Picture description:

New definition of Ampere is defined as the Elementary charge, e. The realization of it is the Ohm's law. It uses the Josephson voltage standard and the quantum hall resistance standard.

New definition of mole is defined as the Avogadro constant, NA. The realization of it is the XRCD method. The mole of Si-sphere is determined by measuring the mass of the Si-sphere and divided by the molar mass of Si.

                                                                                                                                                      Posted Date: 2019/03