closed system

in spectrochemical analysis
https://doi.org/10.1351/goldbook.C01105
See:
mercury flow system (in spectrochemical analysis)
Source:
PAC, 1992, 64, 261. (Nomenclature, symbols, units and their usage in spectrochemical analysis - XIII. Terms related to chemical vapour generation (IUPAC Recommendations 1992)) on page 263 [Terms] [Paper]