DCV-Josephson / Primary Josephson Voltage Standard

Voltage characterization is based on primary Josephson voltage standard. It is a complex system that uses a superconductive integrated circuit chip (two superconductors separated by a thin insulator) to generate stable voltages that depend only on the applied microwave frequencies and fundamental constants. The technique is based on the Cooper pair tunnelling quantum effect, operating at 4 K within a liquid helium Dewar and it is the most accurate method to generate or measure voltage. By international agreement in 1990, is the basis for voltage standards around the world. In the lab we calibrate any voltage-related set-up based on this primary voltage standard.