| 释义 |
goniometer|gəʊnɪˈɒmɪtə(r)|
[ad. F. goniomètre, f. Gr. γωνία angle + µέτρον measure.]
1. An instrument used for measuring angles.
Two kinds of goniometers are used in measuring angles of crystals, the old contact-goniometer or hand-goniometer invented by Carangeot, and the more accurate reflecting goniometer invented by Wollaston.
1766B. Martin (title), New Art of Surveying by the Goniometer. 1802Bournon in Phil. Trans. XCII. 314, I have measured this angle with more than usual care,..having taken the precaution of using several different goniometers. 1854J. Scoffern in Orr's Circ. Sci., Chem. 19 Carangeot's goniometer..consists of two metal rulers fastened together at the pivot a. 1895Story-Maskelyne Crystallogr. §373 The contract- or hand-goniometer. Ibid. §374 The reflection-goniometer of Wollaston.
attrib.1867J. Hogg Microsc. i. ii. 56 Schmidt's goniometer positive eye-piece is so arranged as to be easily rotated.
2. An apparatus for determining the direction from which detected radio waves are coming, without the need for a rotating aerial, consisting essentially of a rotatable detector coil coupled to two fixed primary coils at right angles to one another, each of these being in turn connected to one of a pair of directional aerials also at right angles. Also (and orig.) called a radiogoniometer.
1921B. Leggett Wireless Telegr. viii. 233 The station was located by the Germans, doubtless by means of first a goniometer and then balloon observation, and for several days it was heavily shelled. 1932F. E. Terman Radio Engin. xvi. 591 When it is desirable to avoid rotating a loop antenna..it is possible to obtain the effect of rotation by using two loop antennas at right angles to each other and combining the outputs in a goniometer. 1961H. Jasik Antenna Engin. Handbk. xxviii. 21 Since dipoles are usually employed at frequencies above 50 Mc, a capacity goniometer is frequently used to avoid the necessity of shielding an inductive goniometer.
▸ Originally: any of various instruments for measuring angles in craniometry and anthropometry (now rare). In later use: (Med.) any of various devices used to measure the range of motion of a joint.
1839S. G. Morton Crania Americana 252 The following diagram represents the instrument, which may be called the Facial Goniometer, as applied to a cranium for the purpose of measurement. 1851R. Dunglison Med. Lexicon (ed. 8) 413/1 A ‘facial goniometer’ has been invented by Mr Turpenny, of Philadelphia, which is well adapted for measuring the facial angle. 1875Biennial Retrospect Med. Surg., & Allied Sci. 46 He employed a goniometer, the middle point of which was placed in the axis of rotation of the trunk. 1905A. B. Judson Infl. Growth on Congenital & Acquired Deformities 21 The flexion of the foot on the leg may be conveniently measured by the goniometer. 1959Amer. Jrnl. Surg. 98 356/1 Limitation of motion caused by contracture may be measured by a goniometer. 2003Observer 10 Aug. 2 [She] performs her posture assessment which involves measuring joint angles with a goniometer and examining me with a plumb line..for symmetry. |