[ad. G. spektrometer or F. spectromètre.] An instrument used for measuring the index of refraction.
1874. trans. Lommel’s Light, 144. The determination of the index of refraction can be much more conveniently effected by means of Meyerstein’s Spectrometer.
1878. Smithsonian Rep., 431. The spectrometer stands upon a plate of metal which can be made to revolve so that measurements by repetitions are practicable.
1883. Knowledge, 18 May, 297/1. Professor Clifton of Oxford has brought out a new spectrometer.
Hence Spectrometric a.; also Spectrometry (1902 Webster’s Suppl.).
Cf. F. spectrométrique, -métrie (Littré).
1891. Cent. Dict., Spectrometric.
1903. Agnes Clerke, Probl. Astrophys., 8. The ‘spectrometric’ division of photometry consists in the comparative estimation of ray-intensities.
