2개의 기준유량계를 이용한 유량계 교정장치의 측정불확도 평가에 관한 연구

Abstract

Comparing to the gravimetric and volumetric method, the flowmeter calibration based on the master meter method is relatively economical and convenient, especially for high flowrate The uncertainty of flow quantity and flowrate using the master meter method was evaluated according to the GUM (Guide to the Expression of Uncertainty ill Measurement). In order to apply for the wider flow range, two master meters (electromagnetic flow meter) were employed as reference flowmeters. The uncertainty of the master meter was obtained by combining the statistical variation of the repeated measurements and the variation of fluid density and pipe material due to temperature and pressure changes were scrutinized For a practical application, the uncertainty of calibrator, whose measuring capacity of 1000 ㎥/h obtained by employing two 500 ㎥/h electromagnetic flow meters, was evaluated. The uncertainty budget shows the quantitative contribution of each uncertainty component to the overall uncertainty of the calibrator As a result, It was found that the dominant uncertainties were from the master meter, which was evaluated statistically, and from the process of least squares fitting On the contrary, the uncertainties arising from the variation of the fluid density and the pipe volume due to the temperature and pressure were negligible.