Test results of an automatic calibration system for AC-DC thermal voltage converters and AC voltage sources

An automatic calibration system has been developed for testing ac-dc thermal voltage converters (TYC's) and ac voltage sources. Precision, repeatability, and systematic errors are investigated using the data gathered from 100 mV to 1000 V over a frequency range of 10 Hz to 1 MHz. The ac-dc difference of a TVC is determined by the least-square fit to the characteristic equation E = k(V∗) with ac and dc inputs. A mathematical formalism incorporating the systematic errors and the ac-dc difference, or deviation, caused by the ac input source is developed for data analysis.