A calculable, transportable audio-frequency AC reference standard

Abstract

A transportable ac voltage source is described, in which sinusoidal signals are synthesized digitally in the audio-frequency range. The rms value of the output waveform may be calculated by measuring the dc level of the individual steps used to generate the waveform. The uncertainty of this calculation at the 7-V level is typically less than +5 ppm from 60 Hz to 2 kHz and less than + l o ppm from 30 Hz to 15 kHz.

Analysis of the effect of DAC resolution on RMS value of the signal generated by the digital source of low-frequency standard AC voltage

“…The U B voltage can be determined by performing step calibration [6,10]. The error In the classical approach the effect of the DAC resolution on RMS value of the signal generated by the DSS is considered to be of random nature [11,12].…”

“…A typical DSS generates a stair-shaped sinusoidal signal of effective value from approximately 0.5 V to 10 V and in frequency range from 1 mHz to 1 kHz [6,7,8,9]. The ideal sinusoidal signal and its staircase approximation generated by the DSS are shown in Fig.1.…”

“…Determination of the changed effective voltage by performing new peak-to-peak calibration does not resolve the problem as the waveform is still characterized by the same maximum and minimum voltages. Of course it is possible to measure the new RMS value by, for example, step calibration method [6,10], but for large number of steps per period this can be time-consuming.…”

Analysis of the Effect of DAC Resolution on AC Voltage Generated by Digitally Synthesized Source

“…the problem as the waveform is still characterized by the same maximum and minimum voltages. It is possible to measure the new rms value by, for example, the step calibration method [9], [13], but for a large number of steps per period, this can be a time-consuming procedure. The goal of this paper is to analyze and estimate the effect of the limited DAC resolution on the rms value of the sinusoidal signal generated mainly by the DSS operating in the CST mode and calibrated using the peak-to-peak calibration method.…”

Programmable digitally synthesized source for low-frequency calibrations

“…The DSS described in this paper is an extension of an earlier source designed to provide a calculable ac voltage [2]. A simplified block diagram of the new DSS is shown in Fig.…”