matched cells

Also contains definition of: reference cell (or blank cell) in spectrochemical analysis

in spectrochemical analysis
A pair of cells with closely similar optical properties are called matched cells. One cell is the sample cell while the other, the reference (or blank) cell contains the solvent or a reference solution. In double beam spectrometers, radiation is passed either simultaneously or alternately through the cells. In single beam instruments the cells are moved sequentially into the radiation beam.
PAC, 1988, 60, 1449 (Nomenclature, symbols, units and their usage in spectrochemical analysis - VII. Molecular absorption spectroscopy, ultraviolet and visible (UV/VIS) (Recommendations 1988)) on page 1453