@R05048@ from any source other than the one it is desired to detect or measure.
Sources: Orange Book, 2nd ed., p. 213 [Terms] [Book] PAC, 1994, 66, 2513. (Nomenclature for radioanalytical chemistry (IUPAC Recommendations 1994)) on page 2516 [Terms] [Paper]
Radiation which originates from the source and reaches the detector when no analyte is present.
Source: PAC, 1985, 57, 1453. (Nomenclature, symbols, units and their usage in spectrochemical analysis - V: Radiation sources (Recommendations 1985)) on page 1462 [Terms] [Paper]