https://doi.org/10.1351/goldbook.T06410
  1. (after mass analysis): The sum of the separate ion currents carried by the different ions contributing to the spectrum (this is sometimes called the reconstructed ion current).
  2. (before mass analysis): The sum of all the separate ion currents for ions of the same sign before mass analysis.
Sources:
Orange Book, 2nd ed., p. 206 [Terms] [Book]
PAC, 1991, 63, 1541. (Recommendations for nomenclature and symbolism for mass spectroscopy (including an appendix of terms used in vacuum technology). (Recommendations 1991)) on page 1554 [Terms] [Paper]