double-beam spectrometer (for luminescence spectroscopy)

https://doi.org/10.1351/goldbook.D01842
Double (spectral) beam spectrometers are used where two samples are to be excited by two different wavelengths. A double- (
synchronous
) beam
spectrometer
is a
luminescence spectrometer
in which both the excitation and emission monochromators scan the excitation and emission spectra simultaneously, usually with a fixed
wavelength
difference between excitation and emission.
Source:
Orange Book, 2nd ed., p. 191 [Terms] [Book]