The International System of Units the SI provides the foundation for all measurements in
science engineering economics and society. The SI has been fundamentally revised in 2019.
The new SI is a universal and highly stable unit system based on invariable constants of
nature. Its implementation rests on quantum metrology and quantum standards which base
measurements on the manipulation and counting of single quantum objects such as electrons
photons ions and flux quanta. This book explains and illustrates the new SI its impact on
measurements and the quantum metrology and quantum technology behind it. The book is based on
the book ?Quantum Metrology: Foundation of Units and Measurements? by the same authors. From
the contents: -Measurement -The SI (Système International d?Unités) -Realization of the SI
Second: Thermal Beam Cs Clock Laser Cooling and the Cs Fountain Clock -Flux Quanta Josephson
Effect and the SI Volt -Quantum Hall Effect the SI Ohm and the SI Farad -Single-Charge
Transfer Devices and the SI Ampere -The SI Kilogram the Mole and the Planck constant -The SI
Kelvin and the Boltzmann Constant -Beyond the present SI: Optical Clocks and Quantum Radiometry
-Outlook
