Fundamental uncertainty analysis of flowrate measurement using the ultrasonic Doppler velocity profile method

• An uncertainty analysis of flowrate measurement using UVP is performed based on GUM.
• The relative expanded uncertainty due to internal factors estimated at 0.34%.
• The final expanded uncertainty is estimated to be from 0.42% to 2.13%.
• Actual flow calibration is carried out to validate the uncertainty analysis.

The present paper describes a fundamental uncertainty analysis for a flowrate measurement in a pipe using an ultrasonic Doppler velocity profile method and an evaluation of the estimated uncertainty by an actual flow calibration. The uncertainties are estimated for internal factors originating from the measurement equipment; UVP provided by Met-Flow sa. and external factors depending on on-site measurements, such as the inclination angle of the ultrasonic transducer. The relative expanded uncertainty due to internal factors is estimated to be 0.34% with a coverage factor of 2. The relative external uncertainty including external factors is estimated to be from 0.42% to 2.13% depends on the inclination angle of the transducer. The results of the actual flow calibration under the same condition as the uncertainty analysis are within the range of uncertainty considering the internal factors.