Accession Number : AD0621475

Title :   HYDROACOUSTIC VELOCIMETER SYSTEM.

Descriptive Note : Final rept.

Corporate Author : AMERICAN ELECTRONIC LABS INC COLMAR PA

Report Date : AUG 1965

Pagination or Media Count : 28

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.

Descriptors :   (*UNDERWATER SOUND EQUIPMENT, MEASURING INSTRUMENTS), (*SOUND, VELOCITY), SEA WATER, TRANSDUCERS, ACOUSTIC EQUIPMENT, QUARTZ, MEASUREMENT

Distribution Statement : APPROVED FOR PUBLIC RELEASE