range finder


range finder
any of various instruments for determining the distance from the observer to a particular object, as for sighting a gun or adjusting the focus of a camera. Also, rangefinder.
[1870-75]

* * *

Instrument used to measure the distance from the instrument to a selected point or object.

The optical range finder, used chiefly in cameras, consists of an arrangement of lenses and prisms set at each end of a tube. The object's range is determined by measuring the angles formed by a line of sight at each end of the tube; the smaller the angles, the greater the distance, and vice versa. Since the mid-1940s, radar has replaced optical range finders for most military targeting, and the laser range finder, developed in 1965, has largely replaced optical range finders for surveying and radar in certain military applications.

* * *

      any of several instruments used to measure the distance from the instrument to a selected point or object. One basic type is the optical range finder modeled after a ranging device developed by the Scottish firm of Barr and Stroud in the 1880s. The optical range finder is usually classified into two kinds, coincidence and stereoscopic.

      The coincidence range finder, used chiefly in cameras (camera) and for surveying, consists of an arrangement of lenses and prisms set at each end of a tube with a single eyepiece at its centre. This instrument enables the user to sight an object by correcting the parallax resulting from viewing simultaneously from two slightly separated points. The object's range is determined by measuring the angles formed by a line of sight at each end of the tube; the smaller the angles produced, the greater is the distance, and vice versa. The stereoscopic range finder operates on much the same principle and resembles the coincidence type except that it has two eyepieces instead of one. The design of the stereoscopic instrument makes it more effective for sighting moving objects. It was widely used for land-gunnery ranging during World War II.

      Since the mid-1940s, radar has supplanted optical range finders for most military target-ranging operations. This nonoptical ranging device determines the distance to a target by measuring the time it takes radio pulses to reach the object, bounce off, and return.

      Advances in laser technology led to the development in 1965 of another kind of ranging instrument known as the laser range finder. It has largely replaced coincidence range finders for surveying and radar in certain military applications. The laser range finder, like radar, measures distance by timing the interval between the transmission and reception of electromagnetic waves, but it employs visible or infrared light rather than radio pulses. Such a device can measure distances of up to 1 mile (1.61 km) to an accuracy of 0.2 inch (0.5 cm). It is especially useful in surveying rough terrain where remote points have to be located between rocks and brush.

* * *


Universalium. 2010.

Look at other dictionaries:

  • Range finder — Range Range, n. [From {Range}, v.: cf. F. rang[ e]e.] 1. A series of things in a line; a row; a rank; as, a range of buildings; a range of mountains. [1913 Webster] 2. An aggregate of individuals in one rank or degree; an order; a class. [1913… …   The Collaborative International Dictionary of English

  • range finder — any of various instruments for determining the distance of a target or object from an observer, or from a gun, camera, etc.: also rangefinder n …   English World dictionary

  • range finder — noun a measuring instrument (acoustic or optical or electronic) for finding the distance of an object • Syn: ↑rangefinder • Hypernyms: ↑measuring instrument, ↑measuring system, ↑measuring device * * * noun 1 …   Useful english dictionary

  • range-finder — tolimatis statusas T sritis Gynyba apibrėžtis Prietaisas atstumams iki objektų nustatyti. Reikalingas šaudant iš pabūklų, mėtant bombas, fotografuojant, geodezijoje, astronomijoje ir kt. Tolimačiai skiriami pagal naudojamų elektromagnetinių bangų …   Artilerijos terminų žodynas

  • range finder — tolimatis statusas T sritis fizika atitikmenys: angl. distance meter; range finder; telemeter vok. Entfernungsmeßgerät, n; Entfernungsmesser, m rus. дальномер, m; измеритель дальности, m pranc. distancemètre, m; télémètre, m …   Fizikos terminų žodynas

  • range finder — range′ find er or range′find er n. opt any of various instruments for determining the distance from the observer to a particular object …   From formal English to slang

  • range finder — n. device for measuring distance or range …   English contemporary dictionary

  • range finder — noun Date: 1872 1. an instrument used in gunnery to determine the distance of a target 2. a surveying instrument (as a transit) for determining quickly the distances, bearings, and elevations of distant objects 3. a usually built in adjustable… …   New Collegiate Dictionary

  • range finder adjustment — artilerijos ugnies koregavimas tolimačiu statusas T sritis Gynyba apibrėžtis Sprogimų nuokrypiai nustatomi tolimačiu, o korektūros skaičiuojamos t. p., kaip ir įsišaudant į taikinį. atitikmenys: angl. range finder adjustment; range finder… …   Artilerijos terminų žodynas

  • range finder spotting — artilerijos ugnies koregavimas tolimačiu statusas T sritis Gynyba apibrėžtis Sprogimų nuokrypiai nustatomi tolimačiu, o korektūros skaičiuojamos t. p., kaip ir įsišaudant į taikinį. atitikmenys: angl. range finder adjustment; range finder… …   Artilerijos terminų žodynas


Share the article and excerpts

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

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.