Title: spectral effectiveness
Long Title: IUPAC Gold Book - spectral effectiveness
DOI: 10.1351/goldbook.S05814
Status: current

Definition
The reciprocal of the photon fluence rate, \(E_{\rm{p}}^{0}\), at wavelength \(\lambda \), causing identical photoresponse, \(\Delta \rm{y}\), per unit time (\(\frac{\Delta \rm{y}}{\Delta t}\)). The effectiveness spectrum is directly proportional to the conversion spectrum of the sensory pigment, if spectral attenuance is negligible.

Related Terms
- attenuance: https://goldbook.iupac.org/terms/view/A00513
- conversion spectrum: https://goldbook.iupac.org/terms/view/C01319
- effectiveness: https://goldbook.iupac.org/terms/view/E01897
- photon fluence rate: https://goldbook.iupac.org/terms/view/P04635
- wavelength: https://goldbook.iupac.org/terms/view/W06659

Source
- PAC, 1996, 68, 2223. 'Glossary of terms used in photochemistry (IUPAC Recommendations 1996)' on page 2275 (https://doi.org/10.1351/pac199668122223)

Other Outputs
- html: https://goldbook.iupac.org/terms/view/S05814/html
- json: https://goldbook.iupac.org/terms/view/S05814/json
- xml: https://goldbook.iupac.org/terms/view/S05814/xml

Citation: Citation: 'spectral effectiveness' 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.S05814
License: The IUPAC Gold Book is licensed under Creative Commons Attribution-ShareAlike CC BY-SA 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) for individual terms.
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Disclaimer: The International Union of Pure and Applied Chemistry (IUPAC) is continuously reviewing and, where needed, updating terms in the Compendium of Chemical Terminology (the IUPAC Gold Book). Users of these terms are encouraged to include the version of a term with its use and to check regularly for updates to term definitions that you are using.
Accessed: 2026-06-30T16:04:51+00:00