Standard apparatus for the volt realization in the frequency range from 20 Hz to 1500 MHz

The standard apparatus used to calibrate ac voltmeters in the USSR is described. The test system uses 2 sets of thermoelectric voltage converters rated for voltage values of 0.3, 1, 3, and 10 V over the frequency range of 20 Hz to 30 MHz. The high-frequency converters use vacuum single-components with metal-film resistors. Techniques used to establish the accuracy and precision of the test apparatus are discussed and the results of these investigations are then presented.