A general term for describing a combination of spectral apparatus with one or more
detectors to measure the intensity of one or more spectral bands.
Source:
PAC, 1995, 67, 1725
(Nomenclature, symbols, units and their usage in spectrochemical analysis-IX. Instrumentation
for the spectral dispersion and isolation of optical radiation (IUPAC Recommendations
1995))
on page 1729