Title: spectral radiant intensity
Long Title: IUPAC Gold Book - spectral radiant intensity
DOI: 10.1351/goldbook.S05827
Status: current
Index: quantity

Definition
The radiation intensity, \(I\) at wavelength \(\lambda \) per unit wavelength interval. The SI unit is \(\rm{W m}^{-1}\ \rm{sr}^{-1}\), but a commonly used unit is \(\rm{W nm}^{-1}\ \rm{sr}^{-1}\).

Related Term
- wavelength: https://goldbook.iupac.org//terms/view/W06659

Source
- PAC, 1996, 68, 2223. 'Glossary of terms used in photochemistry (IUPAC Recommendations 1996)' on page 2276 (https://doi.org/10.1351/pac199668122223)

Other Outputs
- html: https://goldbook.iupac.org/terms/view/S05827/html
- json: https://goldbook.iupac.org/terms/view/S05827/json
- xml: https://goldbook.iupac.org/terms/view/S05827/xml

Citation: Citation: 'spectral radiant intensity' 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.S05827
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Accessed: 2026-05-13T19:17:55+00:00