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Constant frequency pulsed phase-locked-loop instrument for measurement of ultrasonic velocityA new instrument based on a constant-frequency pulsed phase-locked-loop (CFPPLL) concept has been developed to accurately measure the ultrasonic wave velocity in liquids and changes in ultrasonic wave velocity in solids and liquids. An analysis of the system shows that it is immune to many of the frequency-dependent effects that plague other techniques. Measurements of the sound velocity in ultrapure water are used to confirm the analysis. The results are in excellent agreement with values from the literature, and establish that the CFPPLL provides a reliable, accurate way to measure velocities, as well as for monitoring small changes in velocity without the sensitivity to frequency-dependent phase shifts common to other measurement systems. The estimated sensitivity to phase changes is better than a few parts in 10 to the 7th.
Document ID
19910069766
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Yost, William T.
(NASA Langley Research Center Hampton, VA, United States)
Cantrell, John H.
(NASA Langley Research Center Hampton, VA, United States)
Kushnick, Peter W.
(Continuous Electron Beam Accelerator Facility Newport News, VA, United States)
Date Acquired
August 14, 2013
Publication Date
October 1, 1991
Publication Information
Publication: Review of Scientific Instruments
Volume: 62
ISSN: 0034-6748
Subject Category
Instrumentation And Photography
Accession Number
91A54389
Distribution Limits
Public
Copyright
Other

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