Semenikhin V. Improving calibration procedures of instruments for electrical resistance measurement and reproduction

Semenikhin V.S. Improving calibration procedures of instruments for electrical resistance measurement and reproduction. – Qualifying scientific work on manuscript rights. Dissertation for obtaining the scientific degree of Doctor of Philosophy in specialty 152 – Metrology and information-measuring technology. - Kharkiv National University of Radio Electronics, Kharkiv, 2024. The dissertation is devoted to the improvement of calibration procedures of instruments for electrical resistance measurement and reproduction by developing measurement uncertainty evaluation procedures based on the kurtosis method and generally improving the quality and efficiency of the results of calibrating insruments for measuring and reproducing electrical resistance, which is an important scientific and practical task. The object of research is the process of calibrating instruments for measuring and reproducing electrical resistance. The subject of research is procedures of calibrating instruments for measuring and reproducing electrical resistance. The purpose of the dissertation is to develop procedures for the measurement uncertainty evaluation at calibrating instruments for measuring and reproducing electrical resistance based on the kurtosis method. The introduction substantiates the relevance of the research topic, formulates the purpose, tasks, object, subject, reveals the scientific novelty, the practical significance of the results obtained, identifies the personal contribution of the applicant, provides data on testing and implementation of the research results into practice, presents the stages of the research, and lists the number of publications on the topic work. The first section analyzes existing methods for calibrating instruments for measuring and reproducing electrical resistance, considers the classification of these instruments for measuring and reproducing, provides the main stages of calibration, analyzes methods for measurement uncertainty evaluation, considers the basic GUM algorithm and its shortcomings, the implementation of the Monte Carlo method for measurement uncertainty evaluation and application kurtosis method to obtain reliable estimates of measurement uncertainty in measuring instruments (MI) calibrations. The second section presents developed procedures for measurement uncertainty evaluation at calibrating electrical resistance measures (hereinafter referred to as ERM) on the basis of the kurtosis method, namely: a procedure for uncertainty evaluation of direct measurements of the value of a ERM to be calibrated using a reference ohmmeter; procedure for uncertainty uncertainty when comparing the value of a ERM to be calibrated with the value of a reference ERM using a comparator; procedure for uncertainty evaluation of indirect measurements of the value of a ERM using a potentiometer. For each procedure, an uncertainty budget was compiled, an experimental study of measurement uncertainty at the calibration of ERM based on the kurtosis method was carried out, and the results obtained were compared with estimates of expanded uncertainty obtained by the Monte Carlo method. Validation of methods for calibrating ERM is considered. The third section presents procedures for measurement uncertainty evaluation at calibrating DC ohmmeters developed on the basis of the kurtosis method, namely: a procedure for uncertainty evaluation of direct measurements with an ohmmeter to be calibrated by a ERM. The features of calibration of analog ohmmeters whis a nonlinear scale, identification of a non-polynomial calibration dependence taking into account instrumental uncertainties of electrical resistance measuring instruments, validation of calibration methods for DC ohmmeters are considered. The fourth section discusses the reproduction of units of electrical resistance using the Ohm standard on the quantum Hall effect, the scaling of the unit of electrical resistance in the state primary standard of Ukraine, and the assessment of the compliance of electrical resistance MIs with metrological requirements based on the results of their calibration. A method for correcting the calibration intervals of the electrical resistance MIs is proposed.