Title: spectral resolution
Long Title: IUPAC Gold Book - spectral resolution
DOI: 10.1351/goldbook.08289
Status: current

Definition
Smallest difference between wavenumbers (or wavelengths or frequencies) at which different spectral properties may be distinguished, measured as the full width at half maximum.

Notes
1) An equivalent definition is the minimum separation of two infinitely sharp lines of equal intensity of radiation that allows the presence of two lines to be seen in the measured spectrum.
2) Resolution depends strongly on the instrument line shape "function" of the spectrometer and on the natural line width.

Related Terms
- full width at half maximum: https://goldbook.iupac.org//terms/view/08251
- instrument line shape: https://goldbook.iupac.org//terms/view/08257
- natural line width: https://goldbook.iupac.org//terms/view/08641
- nominal spectral resolution: https://goldbook.iupac.org//terms/view/08274
- wavelengths: https://goldbook.iupac.org//terms/view/08299
- wavenumbers: https://goldbook.iupac.org//terms/view/08302

Source
- PAC, 2021, 93, 647. 'Glossary of methods and terms used in analytical spectroscopy (IUPAC Recommendations 2019)' on page 674 (https://doi.org/10.1515/pac-2019-0203)

Other Outputs
- html: https://goldbook.iupac.org/terms/view/08289/html
- json: https://goldbook.iupac.org/terms/view/08289/json
- xml: https://goldbook.iupac.org/terms/view/08289/xml

Citation: Citation: 'spectral resolution' 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.08289
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Accessed: 2026-04-17T16:42:58+00:00