Email Document Reference

Enter your email address below and the reference for this document will be sent to shortly from webmaster@ceesi.com.

Title: Advances In Precision Clamp-On And Clamp-On Spool Transit-Time Ultrasonic Flowmeters
Author: Joseph Baumoel
Source: 1999 International Symposium on Fluid Flow Measurement
Year Published: 1999
Abstract: Until recently, the universe of Transit-Time Ultrasonic Flowmetering has been divided into the worlds of Clamp-On and Insert Spool Section instruments. The obvious convenience, higher reliability, lower installation and maintenance cost advantages of Clamp-On instruments was tempered by the security in having transducers pre-installed on a flow profile conditioned and factory calibrated Insert Spool. Advances in Clamp-On Transit-Time Flowmeter and Wide Beam transducer design have now permitted development of Custody Transfer capable field installed Clamp-On (Refractive Beam) ultrasonic flowmeters, and pre-calibrated Wide Beam Clamp-On Spool Section instruments with superior performance to that achievable by the Wetted Transducer (Orthogonal Beam) Spool Section. This has been made possible by advances in Clamp-On Transducer technology which permit matching the transducer to the Sonic Waveguide parameters of the Spools pipe, so that the pipe now becomes an integral part of the ultrasonic flowmeter, rather than an uncertain interposition into the sonic beam. Liquid Signal to pipe Noise ratios exceeding 1000 to 1 has been achieved permitting calibration stability of better than 0.1%. Advances in Sonic Signal Analysis, such as the development of MultiPulse transmission, have resulted in extremely high flow detection sensitivity and calibration stability. Injection of Phase Markers in the MultiPulse sonic transmission signal permits precise measurement of the actual sonic Transit-Time, essential to accurate flowrate computation. Accordingly, Dual Beam Clamp-On Spool Sections now achieve accuracy better than 0.25% of actual flow over flow ranges as high as 100:1. Custody transfer accuracy is also maintained despite substantial variation in the sonic properties of the liquid, as is frequently encountered in actual applications. The paper describes these Wide Beam based Transit-Time instruments, and provides experimental and field data in support of their accuracy and stability. Also presented is data testifying to the accuracy of Wide Beam Clamp-On Transit-Time ultrasonic flowmeters installed in multiple Site Station pipeline management systems.

In order to prevent spam and automated file downloads for documents within the Measurement Library, please follow the instructions below and then you will be able to email a reference to this article.