Comparison of Nonquantum Methods for Calibration of the Digital Source of Very-Low-Frequency AC Voltage

This paper presents methods of calibration of digital sources of ac voltage of very low frequency (0.001-100 Hz) and of effective value from 0.5 to 5 V. This work deals primarily with the calibration methods of the digital source of the sinusoidal signal [digitally synthesized source (DSS)] which is approximated with the staircase waveform. The construction of the DSS and the calibration system is presented. The calibration methods are divided into dynamic and static. Of the dynamic methods, the thermal method and integrating sampling method are briefly presented. Of the static methods, the step and the peak-to-peak methods of calibration are briefly presented. The potential applications, basic features, and accuracy of all four methods are discussed. This paper also presents a comparison of results obtained using the methods of calibration described in this paper.