Uncertainty Estimation of Flowrate Measurement Using UVP

Abstract

We introduce the uncertainty estimation of flowrate measurement using ultrasonic Doppler velocity profiler (UVP). A fundamental uncertainty analysis for a flowrate measurement in a pipe using UVP and an evaluation of the estimated uncertainty by an actual flow calibration are described. The relative expanded uncertainty due to internal factors is estimated to be 0.34% with a coverage factor of 2. In addition, experiments are carried out in a disturbed flow. Flowrate measurement is based on a multi-path measurement using three ultrasonic transducers. To generate the disturbed flow, obstacle plates are installed upstream of the test section. The maximum difference from the reference flowrate given by the national standard calibration facility of water flowrate is over 2% when the measurement is performed at 8D downstream of the obstacle plate. At 25D downstream of the obstacle plate, the deviation is within the fundamental uncertainty level.