detector
(dɪˈtɛktə(r))
Also -er.
[a. L. dētector (Tertull.), agent-n. from L. dētegĕre to detect.]
He who or that which detects.
† 1. A person or thing that discloses, brings to light, or reveals; one who informs against or accuses; a revealer; an informer, an accuser. Obs.
| 1541 Paynel Catiline xxxiv. 52 The detectour is false and corrupted with mede. 1611 Cotgr., Encuseur, a detecter, discloser, appeacher, accuser. 1614 Raleigh Hist. World v. iii. §18 (R.) As a reward unto the detectors of lands concealed. 1637 Bastwick Litany iv. 3 Those should be punished, that were detectors and manifesters of them. 1680 Baxter Cath. Commun. (1684) 30 This is to comply with the World, that taketh the detecter only for the sinner. 1742 Young Nt. Th. ii. 641 A deathbed's a detector of the heart. Here tir'd dissimulation drops her masque. |
2. One who finds out that which is artfully concealed, or which tends to elude observation.
| 1605 Shakes. Lear iii. v. 14 O Heauens! that this Treason were not; or not I the detector! 1657 Evelyn Diary 7 Jan., Dr. Joyliffe..first detector of the lymphatic veins. 1755 Johnson, Detecter, a discoverer, one that finds out what another desires to hide. 1791 Boswell Johnson (1887) I. 407 Rev. Dr. Douglas, now Bishop of Salisbury, the great detector of impostures. 1840 Mill Diss. & Disc., Bentham (1859) I. 352 The keenest detector of the errors of his predecessors. |
3. An instrument or device for detecting the presence of anything liable to escape observation, for indicating any deviation from normal conditions, or the like.
a. An arrangement in a lock by which any attempt to tamper with it is indicated and frustrated. b. A low-water indicator for a boiler. c. A small portable galvanometer, which indicates the flow and direction of a current of electricity, used for testing purposes. d. An apparatus for detecting the presence of torpedoes under water, a torpedo-detector. e. attrib. in various senses, as detector-bar, detector-galvanometer, detector-lock, detector-pad, detector-spring, etc.
| 1833 J. Holland Manuf. Metal II. 275 His success in this attempt was not better than before, for he overlifted the detector of each lock. 1850 Chubb Locks & Keys 13 F is the detector-spring. 1860 Encycl. Brit. XXI. 114/2 A ‘detector’ or common telegraphic galvanometer. 1874 Knight Dict. Mech. s.v., Chubb had a detector in his lock of 1818. 1889 G. Findlay Eng. Railway 75 ‘Detector Bars’ are employed on parts of the line which cannot be seen by the signalman, to prevent the signals being lowered when the line is occupied by a train. Ibid., ‘Detector Locks’ are applied to facing points, and are worked by the wire that works the signals. 1893 Munro etc. Pocket Book of Electrical Rules (ed. 9) 395 Cells should be tested on the thick wire of a detector. Ibid. 396 For fault inspection, a detector or galvanometer, a battery, knife, etc. 1894 Catalogue, Galvanometers and Measuring Instruments:—Detector Galvanometer, wound for intensity, resistance up to 500 Ohms. 1940 Illustr. London News CXCVI. 192/1 Imagine that two vehicles are converging on the crossing, the one on the Twyford road being nearer the junction... The former would reach his detector-pad first, and cause the lights to change in his favour. |
f. Any of various devices or circuits designed to carry out detection (sense 3).
| 1894 O. Lodge Work of Hertz & Successors 29 We can easily see the detector respond to a distant source of radiation now..separated from the receiver, therefore, by several walls and some heavily gilded paper, as well as by 20 or 30 yards of space. 1898 Science Siftings 11 June 117/2 A Hertz-wave ‘detector’ resistance included in the circuit. 1902 Encycl. Brit. XXXIII. 232/2 The coherer, or detector, is inserted between the earth and the outer end of this last wire. 1924 Wireless Weekly 8 Oct. 744/2 Seven valves (all ‘peanuts’), used successively as first detector, oscillator valve, three stages of intermediate frequency, second detector valve, and one stage of transformer-coupled note-magnification. 1928 Morning Post 6 Feb. 3/4 The nature of the circuit connected to the detector helps to determine the amplification. 1957 D. G. Fink Telev. Engin. Handbk. xvi. 148 The separation of the luminance signal, the chrominance subcarrier, and the sound carrier is carried out at the second detector. |