graticule
(ˈgrætɪkjuːl)
[a. F. graticule, ad. med.L. grātīcula, for crātīcula gridiron, dim. of crātis hurdle.]
1. A design or plan divided into squares to facilitate its proportionate enlargement or reduction; the style or pattern of such a division.
| 1887 Gen. Walker in Encycl. Brit. XXII. 714/1 The graticule is sometimes rectangular, sometimes spherical, sometimes a combination of both..Spherical graticules are constructed in various ways. |
2. A transparent plate or cell bearing a grid, cross-wire, or scale, designed to be used with an optical instrument or cathode-ray oscilloscope for the purpose of positioning, measuring, or counting objects in the field of view; the scale, grid, etc., on such a plate. Hence ˈgraticuled ppl. a., fitted with a graticule.
| 1914 Handbk. Artill. Instrum. 42 In front of the eye-piece is fixed..a diaphragm, with spider's web graticules attached to it. 1919 Trans. Opt. Soc. XX. 277 Generally the graticules are on glass and it is usual to refer to the complete discs or plates with the measuring scales or marks on them, as ‘graticules’. Ibid. 286 Graticuled binoculars are not used much for peace purposes. 1920 Nature CV. 563/1 Such motion being observed by a plate micrometer or ‘graticule’ in the observing telescope. 1922 Encycl. Brit. XXXII. 243/1 Graticuled binoculars. 1924 L. C. Martin Opt. Meas. Instr. 27 The use of lines engraved on a glass (a graticule) is finding an increasing favour. 1952 M. Tripp Faith is Windsock ii. 34 By means of a line-of-flight marker, a controllable circular graticule and a movable compass ring, the relative position of the aircraft and a ground feature could be ascertained. 1966 McGraw-Hill Encycl. Sci. & Technol. IX. 430/1 Practically all laboratory oscilloscopes have calibrated horizontal sweeps so that time interval measurements may be read directly from a graticule over the cathode-ray tube screen. 1970 E. M. Slayter Optical Methods in Biol. xii. 282 When exact measurements are required, however, an ocular can be used in which a ruled scale (graticule) is incorporated. The graticule is placed at the first focal plane of the ‘eye lens’ of the ocular. 1971 Physics Bull. July 398/2 A graduation line is centred in the microscope eyepiece graticule. |