Metrological Properties Analysis of Portable Dc Voltage Calibrator with Errors Correction

It is shown that, it is expedient to use a DC voltage calibrator with automatic error correction by double switching inverting method and averaging the output voltage with a low frequency filter for operational monitoring and remote calibration of measuring channels was shown in this paper (Figre 1). A comparison of the dynamic and metrological characteristics of DC voltage calibrators with single- and two-period demodulation has been carried out and operator and time mathematical models have been proposed (Figure 2). Computer simulation of both structures of voltage calibrators in manual and automatic control modes was carried out. The results of experimental studies of a DC voltage calibrator model with single-phase demodulation and averaging by an active low frequency filter are described (Figure 3). Conclusions about the good convergence of experimental results with theoretical assumptions were made; the unadjusted value of the additive displacements in the manual control mode did not exceed ±1 μV. A certain frequency dependence of the additive displacements unadjusted value of the made model has been established and it is determined that its minimum value is at a frequency near 1.2 kHz. Conditions of practical realization of a DC voltage calibrator with automatic correction of additive displacements by the proposed method of switching inverting in the basis of programmable systems on a chip are discussed. Emphasized that in the future it will also adjust the multiplier and additional errors during the reproduction of DC voltage small values in working conditions. The scientific results, presented in this article, were obtained in the frame of research project number 0115U000446, 01.01.2015 - 31.12.2017, financially supported by the Ministry of Education and Science of Ukraine.