modulation number

in comprehensive chromatography
symbol: $n_{\rm{M}}$
https://doi.org/10.1351/goldbook.09956
Number of modulations for a given first-dimension peak.
Source:
PAC, 2017, 90, 181. 'Terminology of separation methods (IUPAC Recommendations 2017)' on page 208 (https://doi.org/10.1515/pac-2017-0111)