3rd ICAI 2024

International Conference on Automotive Industry 2024

Mladá Boleslav, Czech Republic

The use of the Cp index as a criterion for the selection of measurement tools used in MSA analysis Jerzy Feliks AGH University of Krakow Faculty of Management al. Mickiewicza 30, 30-059 Krakow Poland e-mail: jfeliks@agh.edu.pl

Abstract In product quality control various instruments are used to determine the measurable value or to evaluate the so-called alternative properties of the product. In the evaluation of a measurable value, where a numerical measurement result is obtained, it is important to select the right measurement tools in terms of their ability to distinguish measurement results, i.e. their resolution or uncertainty. This paper presents the criteria for the selection of parameters of measuring devices used in the implementation of statistical control of the SPC process and the analysis of MSA measurement systems that is a part of SPC. Examples of determining the parameters of analog and digital measuring instruments depending on its resolution or execution in a specific accuracy class are presented. Keywords: Measurement Systems Analysis MSA, Statistical Processes Control SPC JEL Classification: C190, L620, C690 1. Introduction Limited accuracy of measuring tools, variability of physical conditions in which measurements are carried out, insufficient knowledge of all circumstances related to the studied phenomenon cause that the value obtained as a result of measurement differs from the actual value of the measured value. When developing measurement results, the recommendations of the International Standard for the Evaluation of Uncertainty in Measurement should be followed. This standard, agreed in 1995 is used in various fields of science and technology [6]. The International Standard recommends the use of the term measurement uncertainty, defined as a parameter that characterizes doubts about the value of a measurement result. The measurement uncertainty is the range of values symmetrically distributed with respect to the measurement result, in which the measurement error is contained with a certain probability. The measurement uncertainty value allows you to determine two values between which the actual value of the measured quantity is contained. A measure of measurement uncertainty can be a standard deviation, called standard uncertainty, or an interval with a specific confidence level, called expanded uncertainty. The theory presented in the “Guide to the Expression of Uncertenity in Measurement” [6] shows that the measurement result is a random variable with realizations (values) in such a way that the expected value of the random variable is equal to the true value (the guide uses the name “true value”),

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