characteristic line

https://doi.org/10.1351/goldbook.08462
Spectral line of an atom used for the measurement of analyte concentration by atomic spectroscopy.
Note:
Characteristic lines include resonance and non-resonance lines.
Source:
PAC, 2021, 93, 647. (Glossary of methods and terms used in analytical spectroscopy (IUPAC Recommendations 2019)) on page 715 [Terms] [Paper]