goniometer

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goniometer

[‚gō·nē′äm·əd·ər]
(electromagnetism)
An instrument for determining the direction of maximum response to a received radio signal, or selecting the direction of maximum radiation of a transmitted radio signal; consists of two fixed perpendicular coils, each attached to one of a pair of loop antennas which are also perpendicular, and a rotatable coil which bears the same space relationship to the coils as the direction of the signal to the antennas.
(engineering)
An instrument used to measure the angles between crystal faces.
An instrument which uses x-ray diffraction to measure the angular positions of the axes of a crystal.
Any instrument for measuring angles.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Goniometer

 

(1) In physics, an instrument for measuring the angles between the planes of crystals, and also for measuring the angles of various prisms. Crystals can be distinctively characterized by the angles between their facets. Before the discovery of X-ray structural analysis, the method of measuring crystals with a goniometer was the main means of diagnosing crystalline substances. It was later superseded to a considerable degree by X-ray structural analysis.

Goniometers may be of the contact or reflecting types. The simplest contact goniometer consists of a protractor attached

Figure 1. Single-disk reflecting goniometer: (a) overall view; (b) diagram. C is the collimator, T is the viewing tube, L is the limb, ν is the vernier, and N1 and N2 are normals corresponding to facets a and b. to a ruler; it permits measurement of angles with an accuracy of 0.25°-0.5°. A more precise reflecting goniometer is shown in Figure I.

A crystal attached to a rotating axis is illuminated by a collimated beam of light, and the rays reflected from its facets are observed in sequence by looking into a viewing tube T (a single-circle goniometer). The angles of rotation of the crystal are read from a scale. In more advanced two-circle goniometers (developed by Fedorov, Gol’dshmidt, and Chapskii), the crystal or the viewing tube can be rotated about two axes. The precision of measurement is to within l’ to 10’-20’.

REFERENCES

Flint, E. E. Prakticheskoe rukovodstvo po geometricheskoi kristallografii, 3rd ed. Moscow, 1956.
Flint. E. E. Nachala kristallografii, 2nd ed. Moscow, 1961.

M. P. SHASKOL’SKAIA

(2) In anthropology, a goniometer is an instrument for measuring angles of curvature of the spine, the facial angle, the angle of the nose, and so on. A contact goniometer consists of a graduated metal plate in the form of an arc; its ends are joined by a transverse plate with a rotating pointer with a plumb bob attached to its center. The goniometer is attached to dividers (for example, of the sliding type), and the size of the angle being measured is determined by the distance of deflection of the pointer from the vertical.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.

goniometer

i. A direction-finding device commonly used in radio location and radio navigation. It has a fixed antenna, and the direction response is varied electrically. Using a method called phase comparison, it senses the angle between a fixed reference point and the direction from which a radio signal is being received. See automatic direction finder.
ii. A motor-driven instrument used with four stationary aerials to a deliver rotating signal field for VOR (very high frequency omnidirectional radio-range).
An Illustrated Dictionary of Aviation Copyright © 2005 by The McGraw-Hill Companies, Inc. All rights reserved
References in periodicals archive ?
To round out the picture, it is to be noted that Adolf B/it tried to give new impetus to the principle of contact through his investigations of "new contact goniometers for measurement, calculation and drawings of crystals" in 1933.
The study goals were to: (1) compare measurements obtained using a universal plastic goniometer and an electrogoniometer with those obtained by radiographic assessment, (2) determine the repeatability of the measurements, (3) present descriptive statistics for joint measurements obtained during this study to serve as a species reference, and (4) compare measurements obtained from anesthetized animals to those obtained from frozen-thawed carcasses to determine whether they could serve as a potential model for future goniometry studies in avian species.
Universal Goniometer. Two observers measured all subjects' ROM three times independently with an UG.
sitting with a straight leg on the table as part of the goniometer measurements, as will be described.
Hansson, "Improving goniometer accuracy by compensating for individual transducer characteristics," Journal of Electromyography and Kinesiology, vol.
The goniometer can be paired with either a photometer (goniophotometer), for angular luminous intensity measurements only, or with a spectroradiometer (goniospectroradiometer) if angular color information is required.
Unfortunately, clinical measurements of the cervical ROM by UG are often inconsistent and are claimed to be less precise compared to the measurements of other body's joints mobility.7,16 These in-consistencies and lack of accuracy may be due to inter-tester differences in measurement technique, including differences in patient and goniometric positioning.4,7,17 This may also be due to improper alignment of the goniometer, lack of anatomical landmarks, variability of the neutral head position and soft tissues thickness in the cervical region.17,18
reliability of weightbearing ankle DF lunge measurement using inclinometer, goniometer, and distance methods; 2.
Rothstein et al (1983) demonstrated acceptable reliability for measuring range of flexion (ICC from 0.85 to 0.97) and extension (0.92 to 0.95) using different types of goniometers in patients with elbow pathology.
Bauer of Konigsberg (Kaliningrad) who first recognized (1881) that optic axis angle goniometers originally devised by Des Cloizeaux (1817-1897) and improved in 1871 by Groth (1843-1927) were suitable also for the Kohlrausch method.