depth finder

depth finder

▪ measurement device
also called  echo sounder 

      device used on ships to determine the depth of water by measuring the time it takes a sound (sonic pulse) produced just below the water surface to return, or echo, from the bottom of the body of water. Sonic depth finders are in operation on practically every important class of ship, naval and merchant, and are also used on small craft.

      Sonic pulses are also sent out to detect underwater objects by the same principle. During World War II the name sonar (q.v.) was applied in an analogy to radar, and the device was used extensively to detect submarines. In addition to protecting ships from shoal water, peacetime uses include locating fish, measuring the thickness of ice in Arctic regions, and oceanographic charting. Sonic depth finders can be operated repetitively, recording thousands of soundings per hour, to prepare a profile of the ocean floor. Hydrographers use echo sounders in charting the oceans and in survey work to discover underwater pinnacles and shoals.

      One of the first practical depth sounders, the so-called Hayes sonic depth finder, developed by the U.S. Navy in 1919, consisted of (1) a device to generate and send sound waves to the ocean floor and receive the reflected waves and (2) a timer calibrated at the speed of sound in seawater that directly indicated water depth. About 1927 a similar device was manufactured under the trade name Fathometer. The basic principles used in these early devices have not been significantly changed.

      In the modern system a transmitter supplies a powerful pulse of electrical energy, and a transducer converts the pulse into an acoustical pressure wave in the water and receives its echo, converting it back into electrical energy, which can be amplified and applied to an indicator. Audible frequencies of less than 15 kilohertz are commonly employed.

* * *


Universalium. 2010.

Игры ⚽ Нужен реферат?

Look at other dictionaries:

  • Depth finder — A depth finder could mean any of the following: Sonar: use of underwater sound propagation to measure depth Fathometer or fishfinder: a device to locate fish at various water depths Echo sounding: a technique using sound pulses to measure depth… …   Wikipedia

  • depth finder — noun navigational instrument used to measure the depth of a body of water (as by ultrasound or radar) • Hypernyms: ↑navigational instrument • Hyponyms: ↑sonic depth finder, ↑fathometer …   Useful english dictionary

  • depth finder — /ˈdɛpθ faɪndə/ (say depth fuynduh) noun → depth sounder …  

  • depth finder — a sonar device used to determine depth and bottom structure and to locate fish …   Dictionary of ichthyology

  • sonic depth finder — noun depth finder for determining depth of water or a submerged object by means of ultrasound waves • Syn: ↑fathometer • Hypernyms: ↑depth finder * * * noun : an instrument for determining the depth of a body of water or of an object below the… …   Useful english dictionary

  • acoustic depth finder — akustinis gylmatis statusas T sritis Standartizacija ir metrologija apibrėžtis Apibrėžtį žr. priede. priedas( ai) Grafinis formatas atitikmenys: angl. acoustic depth finder; acoustic depthometer vok. Echomesser, m rus. акустический глубиномер, m; …   Penkiakalbis aiškinamasis metrologijos terminų žodynas

  • sonic depth finder — n. FATHOMETER …   English World dictionary

  • depth sounder — /ˈdɛpθ saʊndə/ (say depth sownduh) noun a device for estimating the depth of water beneath a vessel by emitting sonic waves and measuring the time it takes for their echoes to return from the sea floor. Also, depth finder …  

  • sonic depth finder — a sonar instrument that uses echolocation to measure depths under water. Cf. Fathometer. [1925 30] * * * …   Universalium

  • Finder (software) — Infobox Software name = Finder caption = Screenshot of a Mac OS X v10.5 Finder window developer = Apple Inc. latest release version = 10.5.6 latest release date = September 15, 2008 latest preview version = latest preview date = operating system …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”