double-beam spectrometer (for luminescence spectroscopy)
Double (spectral) beam spectrometers are used where two samples are to be excited by two different wavelengths. A double- (@S06219@) beam @S05837@ is a @L03645@ in which both the excitation and emission monochromators scan the excitation and emission spectra simultaneously, usually with a fixed @W06659@ difference between excitation and emission.
Orange Book, 2nd ed., p. 191 [Terms] [Book]