| 释义 |
▪ I. photometer, n.|fəʊˈtɒmɪtə(r)|
[f. Gr. ϕῶς light, photo- + -meter: in mod.L. photometrum, 1760.]
1. The name of instruments (of many kinds) for measuring the intensity of light, or for comparing the relative intensities of light from different sources.
[1760: see photometry.] 1778Phil. Trans. LXVIII. 487 We wish for an Hygrometer, an Electrometer, a Photometer. 1793Rumford ibid. LXXXIV. 73, I have now brought the principal instrument to such a degree of perfection, that, if I might without being suspected of affectation, I should dignify it with a name, and call it a photometer. c1865Letheby in Circ. Sc. I. 92/2 Leslie and Wheatstone have also invented photometers. 1893Brit. Jrnl. Photogr. XL. 811 Very many different patterns of photometers have been introduced and used during the last thirty years.
2. Special Combs.: photometer bench, an apparatus similar to an optical bench for the support of a photometer and light sources; cf. photometric bench; photometer head, the part of a photometer by means of which the comparison or measurement is effected.
1900W. M. Stine Photometrical Measurements iii. 104 The Reichanstalt photometer bench is commonly made for a maximum working distance between the light sources of either 200 or 250 centimetres. 1966Large & Wilman in Hewitt & Vause Lamps & Lighting vii. 89 An appropriate calibrated lamp is..mounted on the photometer bench.
1907Sheppard & Mees Investigations Theory Photogr. Process i. ii. 27 Simmance and Abady's new flicker photometer possibly forms the best of the bench photometer heads. 1966Large & Wilman in Hewitt & Vause Lamps & Lighting vii. 89 Distance between the photometer head and lamps may be adjusted and accurately measured. Ibid., The photometer head may consist of either a photocell or a visual device such as the Lummer-Brodhun Contrast Head. 1973W. Thomas SPSE Handbk. Photographic Sci. & Engin. ii. 153 Photometer heads are used in conjunction with some means for varying the luminance of one or both surfaces in a known manner so that a photometric balance may be obtained.
▪ II. phoˈtometer, v.
[f. the n.]
trans. To measure the brightness of (a light source or an illuminated surface) by means of a photometer. Hence phoˈtometered ppl. a., phoˈtometering vbl. n.
1900Jrnl. Franklin Inst. CXLIX. 291 The leading makers now photometer each and every lamp, and the practice of photometering a few and picking out the remainder by the eye is past. 1917Physical Rev. X. 695 The photographs taken thus far are not suitable for photometering, but arrangements are complete for taking such photographs, and for measuring the intensity of the lines. 1923Amer. Jrnl. Sci. CCV. 459 The films were photometered with a microphotometer at the Bureau of Standards. Ibid. 460 No high precision was sought in the photometering. Ibid. 461 The photometered maximum in the mixture lies between the positions of the two simple maxima. 1966D. G. Brandon Mod. Techniques Metallogr. iii. 127 The minimum area that can be photometered is principally limited by the size of the diffraction image of the spot selected for photometry. |