[en] Propagation of inherent inhomogeneities or tracers in flowing liquids is used to measure flow. The peak value obtained from a cross-correlation analysis of downstream and upstream sensor signals is used to determine the tracer transit time and hence the flow. Performance of a 'clamp-on' ultrasonic cross-correlation flowmeter developed by Canadian General Electric under contract from Atomic Energy of Canada Limited (AECL) was evaluated at the Chalk River Nuclear Laboratories of AECL. During this work, the effects of: (1) cross-correlation parameters, (2) filtering of correlator output and (3) use of an add-only polarity coincidence correlator on the standard deviation of transit measurements were investigated both theoretically and experimentally. Comparison of ultra-sonic cross-correlation flowmeter readings against gravimetric flow measurements gave a standard deviation of 2% of reading. (author)

[en] An ultrasonic cross-correlation flowmeter, developed to assist in improving performance of heavy water plants, was evaluated. Overall performance of the flowmeter is satisfactory. The flowmeter is ideally suited to industrial applications and has an accuracy and repeatability comparable to many laboratory instruments. An accuracy of 3% is readily obtainable. This new 'clamp-on' portable flowmeter should prove useful in applications which provide flow measurements in systems where pipe penetration is too costly or not practical, verify or replace existing flowmeters, and measure flows in lines not previously instrumented to provide better control or to verify performance of systems

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