An improved CCC and QHR system for resistance standards metrology

We have improved on the design of the integrated cryogenic current comparator (CCC) and QHR system used for the characterisation of standard resistors to the quantum Hall standard of resistance. Improved current sources are used with a larger and more sensitive CCC. The CCC is mounted in a separate cryostat so that both the CCC and QHR system can be used independently.