Experimental studies of the RF-DC differences of voltage standards

The RF-DC differences (d) of primary voltage standards were determined by experimental and theoretical procedures. The voltage standards, with different operating principles and designs, have been compared with CTVCs (coaxial thermal voltage converters) at frequencies from 1 to 100 MHz. The method recommended for determining the d values is to derive an empirical formula and then to correct if from measured data. The uncertainty of primary voltage standards established by this method is +or-0.007% at 1 MHz, +or-0.01% at 3 MHz, +or-0.02% at 10 MHz, 0.07% at 30 MHz, +or-0.15% at 50 MHz, and +or-0.2% at 100 MHz. This specification is shown to be reliable while leaving sufficient margin for error.<>