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 (https://doi.org/10.1351/pac199264020261)