No abstract

The volt has been determined to high accuracy using a liquid electrometer. The representation of the volt maintained by the Josephson effect using the value of 2 e/h = 483.594 THz/V recommended by the Consultative Committee on Electricity of the International Committee of Weights and Measures in 1972 has been measured to be smaller than the SI volt by (8.09 ± 0.27) ppm. This implies that the SI value of 2 e/h is (483.59791 ± 0.00013) THz/V. Full experimental details are given.

No abstract

Since December 1992, CSIRO and BHP have been field trialing rf HTS SQUID magnetometers for mineral prospecting applications. Ten field trials in widely varying environments (from -16°C to +4OoC ambient temperatures) in mostly remote locations saw the development of a system which can be operated in many configurations including ground based and airborne Transient ElectroMagnetics (TEM). The magnetometer system has been developed to a point where, at late times in TEM applications, the SQUID system has a higher signal-to-noise level than the competing traditional coil technology. In some trials, a SQUID magnetometer detected anomalies at later times than were observed with the coil system, indicating an enhanced ability to detect highly conductive targets. This paper reviews development of our 3-axis SQUID magnetometer. SQUID systems as B field sensors have advantages over coils which are dB/dt type sensors. We will discuss the importance of these advantages for mineral prospecting in regions with a conducting soil cover or overburden typical of the Australian landscape.