HP Data Explorer 4 Series - Manual (Page 393)

Isotopes
Data Explorer ™ Software User’s Guide B-5
B
Figure B-4 Mass Spectrum of Angiotensin I at Resolution
1,000
If isotopes cannot be resolved, the highest resolution you can
obtain is limited by the width of the isotopic envelope. The
isotopic envelope is the mass range of the combined isotopes,
as measured at the half height of the tallest isotope peak in the
compound (Figure B-5).
Figure B-5 Unresolved Isotopes
M +
(M+1) +
(M+2) +
isotopic envelope