Investigation of Two Different Techniques for Accurate Measurements of Sinusoidal Signals

In this paper, two different techniques for the determination of the rms value of sinusoidal AC voltage at the range of 2V are practically compared: non-thermoelectric technique (via the direct measurement using a precise high sensitive digital voltmeter, and the comparison method using a precise AC voltage calibrator) and thermoelectric technique (via the null thermoelectric technique, and the algorithmic thermoelectric technique using a calibrated multijunction thermal converter (MJTC)). A series of comparisons between the four methods have been discussed and evaluated at frequencies from 20 Hz to 100 kHz to investigate the level of performance and competitiveness. The comparison results showed that the four applied methods agreed within values of 80μV ± 15μV/V and 68μV ± 11μV/V at frequencies of 20 Hz and 100 kHz, respectively. KeywordsAC voltage measurement, AC-DC thermal transfer, uncertainty budget, proficiency test.