Determination of the frequency dependence of the AC-DC voltage standard at IEN

This paper reports on the procedures and devices, some of them of a new type, developed at Istituto Elettrotecnico Nazionale "Galileo Ferraris" (IEN) for the determination of the frequency dependence of the ac-dc transfer standard. The group of multijunction thermal converters used as primary reference standards has been associated with a special converter whose transfer difference has been reduced and evaluated as a function of frequency. A step-up procedure has been introduced for higher voltages, and special range resistors, whose characteristics can be adjusted to be as close as possible to that of a compensated divider, have been designed and tested for voltages higher than 100 V.