Chromatographic separations carried out using constant density conditions. The temperature and pressure may be altered during the run (originally the term isoconfertic separation was used but this term is not recommended).
Source:
PAC, 1993, 65, 2397. 'Nomenclature for supercritical fluid chromatography and extraction (IUPAC Recommendations 1993)' on page 2401 (https://doi.org/10.1351/pac199365112397)