mass resolving power

in mass spectrometry
https://doi.org/10.1351/goldbook.M03730
Commonly and also acceptably defined in terms of the overlap (or 'valley') between two peaks. Thus for two peaks of equal height, masses \(m_{1}\) and \(m_{2}\), when there is overlap between the two peaks to a stated percentage of either peak height (10% is recommended), then the resolving @[email protected] is defined as \(\frac{m_{1}}{m_{1} - m_{2}}\). The percentage overlap (or 'valley') concerned must always be stated.
Source:
PAC, 1978, 50, 65. (Recommendations for Symbolism and Nomenclature for Mass Spectroscopy) on page 72 [Terms] [Paper]