UKAS AC voltage measurement accreditations 1966-1997

UKAS AC Voltage calibration accreditations have evolved progressively in the last 30 years. For the majority of this time UKAS electrical calibration accreditations have relied on one or two well known AC-DC Thermal Transfer Standards. However in recent years Electronic Reference Standards have been developed and the previous monopoly of thermal transfer standards is now challenged. Improved uncertainties of measurement are being sought from the National Physical Laboratory (NPL) by UKAS accredited laboratories so that they can improve their capabilities