surface coverage, θ in surface analysis

https://dx.doi.org/10.1351/goldbook.S06165
Number of adsorbed molecules on a surface divided by the number of molecules in a filled monolayer on that surface.
Source:
PAC, 1979, 51, 2243 (General aspects of trace analytical methods - IV. Recommendations for nomenclature, standard procedures and reporting of experimental data for surface analysis techniques) on page 2247