Metrological evaluation of the interlaboratorial comparison of the ultrasonic flowmeter calibration

Abstract

8 f. : il.This work deals with the metrological evaluation of the same ultra-sonic flowmeter, when calibrated in two different calibrating systems, belonging, respectively, to two accredited laboratories, both operating according to the manufacturer’s installation technical specification, and following the minimum requirements, as specified in international standards and recommendations. The research investigated the effect in calibration of the installation of a valve and a long curve upstream of the measurement straight section, as dimensioned according to the applicable standards. It was concluded that longer straight sections should be specified, so that the influence of the installation in the calibration could be neglected. The development of the present work was motivated by the growing utilization of ultrasonic flowmeters by the oil industry, and by the urgent need to contribute to the advance of the technology and the applicable standardization. In this aspect, this work contributes to (a) a better understanding of the measurement technology and of the calibration procedure of ultra-sonic liquid flowmeters, (b) the advance of the technology standardization, since it includes a critical analysis of the minimum requirements, as specified by the standards, and (c) improving the laboratory accreditation criteria for flow meter calibration, because the influence of the installation in the calibration was experimentally shown