News

Outlines the recent development of the “QuantW”, an affordable, portable quantised Hall resistance (QHR) standard that uses as its measuring component a room temperature DC current comparator bridge. We describe the characteristics of the QHR devices developed for this system, and give details of the refrigerator and integrated 8 T magnet which can be top-loaded as a single unit into a transport dewar. We discuss the measurements required to ensure an accurate transfer from a QHR device to a wire resistor, and show that the QuantW can be used to meet these requirements.