1. The theory of errors and processing of measurement results

1 Introduction The purpose of measurement is to obtain a result, i.e. estimates of the true value of a physical quantity. For this measurement it is necessary to carry out with the greatest possible reliability and accuracy. But no matter how accurate and perfect the means and methods of measurement may be and how carefully the measurements may be carried out, their result always differs from the true value of the measurand, i.e. determined with some error. Errors arise because of the imperfection of the applied methods and measuring instruments, the variability of the quantities and individual characteristics of the operator (experimenter) affecting the measurement result, etc. Since any measurements are almost always accompanied by the appearance of various errors, including random ones, the processing of measurement results must contain operations on random variables. These operations are performed by the methods of probability theory and mathematical statistics. Statistical processing of measurement results - processing of measurement information in order to obtain reliable data. The set of problems solved with the help of measurements determines the diversity of the types of statistical processing of their results. If a direct measurement of a physical quantity is carried out once (the so-called one-time direct measurement), then the result of the measurement is a direct reading of the measuring instrument. In this case, the error of the measurement result is often taken as the error of the measuring instrument. By the way, when using the term “measurement result”, it is necessary to clearly indicate what it refers to: the indication of the measuring instrument, the corrected or uncorrected result, and whether the results of several measurements were averaged. It should be noted that the corrected measurement result is the value obtained by means of the measurement value and refined by introducing the necessary corrections into it for the effect of the assumed systematic errors. In the case of multiple observations, the measurement result and its error are found by various methods of statistical processing of all performed observations.