additivity

of mass spectra
https://doi.org/10.1351/goldbook.A00136
The process by which each chemical species present in the ion source at a certain @P04420@ makes a contribution to the total @M03749@ which is the same as that which it would give if that chemical species alone were present in the ion source at a pressure equal to this certain @P04420@.
Source:
Orange Book, 2nd ed., p. 206 [Terms]