Towards a Calibration-free Ultrasonic Clamp-on Flow Meter: Pipe Diameter Calibration using a Matrix Array

Activity: Talk or presentationTalk or presentation at a conference

Description

Current ultrasonic clamp-on flow meters are manually calibrated. This process is based on manual placement of two single-element transducers along a pipe wall. Due to the usually unknown pipe properties and inhomogeneities in the pipe geometry, the axial distance of the transducers needs to be manually calibrated to align the location of the emitted beam on the receiver. In this work it is presented an automatic calibration procedure, based on matrix transducer arrays, to provide calibration information that would normally be entered into the instrument manually prior to ultrasonic clamp-on flow measurements. The calibration consists of two steps: First, along the axial direction of the pipe, Lamb waves are excited and recorded. Then, the measured time signals are combined with the Rayleigh-Lamb dispersion equation to extract pipe wall thickness and bulk wave sound speeds. Second, along the circumferential direction of the pipe, a specific Lamb wave mode is excited and recorded, from which the pipe diameter is estimated. The potential of both calibration procedures is shown, and the necessity of a matrix transducer array (i.e. small elements) is highlighted
Period2 Dec 2019
Event title178th Meeting of the Acoustical Society of America
Event typeConference
LocationSan Diego, United States