Assessment of Errors of a Voltmeter Prototype Based on ATmega8 Microcontroller and its Virtual Model in Proteus

The article considers the development features of prototypes and virtual models of measuring instruments. The measurement errors of two DC voltmeters are investigated: a prototype on a prototyping board and its virtual model. The voltmeter prototype is implemented on the ATmega8 microcontroller with a four-bit indicator; the virtual model is developed in the Proteus environment and completely repeats the prototype schematic diagram. The GW Instek GPC power supply and the VOLTCRAFT MXD laboratory multimeter were used as reference tools for calibrating voltmeters. The absolute and relative errors of the voltmeter prototype and its virtual model in the range of 0–6 V have been assessed. It has been established that in the range of 0–1 V the high relative error of measuring voltage by the voltmeter prototype is due to the influence of the error in setting the power supply voltage, as well as deviations from the nominal values of the actual values of the circuit elements parameters. The minimum relative error of measuring voltage by the voltmeter prototype was less than 1% in the range of 5–6 V. A comparative analysis of the results of assessing the errors of the voltmeter prototype and its virtual model has been carried out and a conclusion about the comparable accuracy of the virtual model and the real prototype with equal power quality parameters has been made. The results obtained will be useful in voltage quality studies at the stages of developing prototypes and virtual models of other types of measuring instruments.