APMP International Comparison of AC-DC Transfer Standards at the Lowest Attainable Level of Uncertainty

The paper presents preliminary results of the APMP.EM-K6a key comparison of ac-dc transfer conducted during 2000-2003. The ac-dc voltage transfer difference of the travelling standard was measured at 3 V and selected frequencies from 1 kHz to 1 MHz that included those of the CCEM-K6a key comparison. Also discussed are the methods used to compare TVCs with different input connectors, and to link the results to the parent CCEM comparison