plate height, \(H_{\text{eff}}\)

in chromatography
https://doi.org/10.1351/goldbook.P04693
The column length (\(L\)) divided by the plate number: \[H=\frac{L}{N}\] It is also called the height equivalent to one theoretical plate (HETP).
Source:
PAC, 1993, 65, 819. (Nomenclature for chromatography (IUPAC Recommendations 1993)) on page 848 [Terms] [Paper]