Analysis of metrological properties of DC voltage calibratolrs
Students Name: Dubchak Marian Petrovych
Qualification Level: magister
Speciality: Quality, Standardization and Certification
Institute: Institute of Computer Technologies, Automation and Metrology
Mode of Study: part
Academic Year: 2020-2021 н.р.
Language of Defence: ukrainian
Abstract: In the master’s qualification work the analysis of metrological properties of DC voltage calibrators showed that the limit of permissible values of their errors should be at the level of several hundredths of a percent, the unit of reproducible voltages at the level of tenths of a microvolt. Traditionally, such metrological characteristics of calibrators at the place of operation are provided by adjusting them by the operator after a certain time for their entry into operation. It is also shown that in operating conditions the additive component of the error can change significantly during changes in environmental conditions, supply voltages and over time and must be adjusted for each set value of codes. It is noted that in multiband DC voltage calibrators with automatic switching of playback subbands there is an additional additive component of the error due to the residual parameters of the switching elements of the scalable coded voltage divider. It is shown that in the known structures of DC voltage calibrators with auto- offset bias there are limited functionality due to DC voltage reproduction in only one subband of reproduction, long enough time to set calibrated voltage values due to use of low frequency filters with high time constant and complexity of technical implementation of portable structure. calibrators for unipolar power supply. The value of the uncorrected additive component of the voltage calibrator with self-correction of displacements is estimated, which for the selected modern element base for the practical implementation of the calibrator will be only hundreds of nanovolts. It is shown that the error of reproducible values of direct voltage by portable calibrators with auto correction of displacements will be practically determined only by the multiplicative component, which is proportional to the sum of errors of reference voltage source, coded voltage divider and scalable coded voltage divider.