HYDROACOUSTIC VELOCIMETER SYSTEM.

Abstract

The highly accurate acoustic velocimeter was designed to measure the velocity of sound in seawater, under laboratory conditions, at pressures up to 10,000 psi with an accuracy of (one one-hundredth of one percent). This velocimeter is ultimately intended as a standard device for calibrating other velocimeters. The following techniques comprise the basis of this system: (1) single-harmonic test signal method: the phase-difference changes of a high-frequency test signal (25 Mc) are observed and recorded while the distance between two transducers is changed by a known, precise amount and (2) Transient test signal method: a transducer is shock excited by a very short electrical pulse, and the propagation time of the wavefront to a second transducer, a known distance from the first, is determined. Use of the two methods results in a selfchecking system. Agreement of the results of the two methods confirms the precision of the measurement.

Document Details

Document Type
Technical Report
Publication Date
Aug 01, 1965
Accession Number
AD0621475

Tags

DTIC Thesaurus Topics

  • Accuracy
  • Agreements
  • Frequency
  • Frequency Bands
  • Measurement
  • Measuring Instruments
  • Precision
  • Pressure Measurement
  • Radio Frequency
  • Standards
  • Transducers
  • Velocimeters
  • Wavefronts

Fields of Study

  • Physics

Readers

  • Fluid Dynamics.
  • Radar Systems Engineering.