Experimental studies of the RF-DC differences of voltage standards

The RF-DC differences (d) of primary voltage standards have been determined by experimental and theoretical processes. Comparisons of five different types of voltage standards have been made. The RF-DC differences of some standards at frequencies from 10 Hz to 300 MHz, or even up to 1 GHz, are quite small, but the d value at frequencies from 0.1 to 50 MHz are not as small as they could be. The recommended method for determining d values is to derive an empirical formula and then to correct it from measured data. The uncertainties of primary voltage standards established by this method are ±0.007% at 1 MHz, ±0.01% at 3 MHz, ±0.02% at 10 MHz, ±0.07% at 30 MHz, ±0.15% at 50 MHz, and ±0.3% at 100 MHz