Title: field level
Long Title: IUPAC Gold Book - field level
DOI: 10.1351/goldbook.F02361
Status: current

Definition
Logarithm of the ratio of two values of a field quantity, usually amplitude. Levels are expressed in different ways: \(L_{F}=\ln (\frac{F}{F_{0}})\ N_{\rm{p}}\), where \(N_{\rm{p}}\) is the symbol for the unit neper coherent with the SI, or \(L_{F}=20\ \log _{10}(\frac{F}{F_{0}})\ \mathrm{dB}\), where \(\mathrm{dB}\) is the symbol for the unit decibel.

Related Terms
- decibel: https://goldbook.iupac.org//terms/view/D01546
- neper: https://goldbook.iupac.org//terms/view/N04106

Source
- Green Book, 2nd ed., p. 79 (https://goldbook.iupac.org/files/pdf/green_book_2ed.pdf)

Other Outputs
- html: https://goldbook.iupac.org/terms/view/F02361/html
- json: https://goldbook.iupac.org/terms/view/F02361/json
- xml: https://goldbook.iupac.org/terms/view/F02361/xml

Citation: Citation: 'field level' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. 10.1351/goldbook.F02361
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Accessed: 2026-06-20T02:24:23+00:00