EVALUATION OF THE CALCULABLE HIGH-FREQUENCY AC-DC STANDARD

A calculable, high-frequency (HF) ac-dc transfer standard has been dev eloped at NMi Van Swinden Laboratorium (VSL). An improved model which contains a more detailed description of the thermal element with the e nd disc, connecting leads, and the housing is presented together with the results of the ac-dc transfer measurements. The major result is a calculated shift of about 3400 mu V/V in the ac-dc difference at 100 M Hz of the 4 V HF ac-dc standard. Based on this model, a 2 V standard i s under development. The first results of this standard confirm the ne w modeling.