RESEARCH AND APPLICATION OF METHODS FOR CALCULATING THE MEASUREMENT UNCERTAINTY OF INDUSTRIAL FLOWMETERS

Abstract

To create conditions for the recognition of Kazakhstani certificates of conformity and the results of product tests, an assessment of measurement uncertainty is required. In this regard, there has been an increase in the practical application in Kazakhstan of the concept of measurement uncertainty. The authors developed a physical stand for a mobile complex designed to verify electromagnetic flowmeters at the place of operation. To obtain verification results, programs were developed to calculate the uncertainty of an electromagnetic flowmeters using the NI LabView software. In addition, a model for estimating the uncertainty of the relative error of flowmeters was proposed, and the measurement uncertainty was estimated using three methods: standard, Monte Carlo and Kragten. Finally, a comparative analysis was conducted on the results of the estimation of the uncertainty of the relative error of the industrial electromagnetic flowmeter. All methods give standard uncertainty values that do not exceed the acceptable range of relative error (± 1%). However, Monte Carlo method gives better results for sufficiently large number of simulations. No significant differences between the results obtained using standard and Kragten methods were discovered. The Kragten method is preferable in the absence of the need to calculate the sensitivity coefficients when calculating the total standard uncertainty, which is important for complex measurement equations.