![](/assets/images/picto-drapeau-france-3a76576a5d60a512053b4612ab58dae5.png)
1. Fundamental law of thermal radiation: Planck's law. The black body
1.1 Definition of luminance
Consider an elementary surface of area dS around a point O (figure
1
) a straight line Δ passing through O making an angle θ with the normal ON to the surface, and the elementary solid angle dΩ (in sr) of axis Δ. The radiative flux d Φ (in W) in the wavelength interval between λ and λ + d λ, propagating to or from dS, within d Ω is written :
...
Exclusive to subscribers. 97% yet to be discovered!
You do not have access to this resource.
Click here to request your free trial access!
Already subscribed? Log in!
![](/assets/images/logo-eti-286623ed91fa802ce039246e516e5852.png)
The Ultimate Scientific and Technical Reference
This article is included in
Physics of energy
This offer includes:
Knowledge Base
Updated and enriched with articles validated by our scientific committees
Services
A set of exclusive tools to complement the resources
Practical Path
Operational and didactic, to guarantee the acquisition of transversal skills
Doc & Quiz
Interactive articles with quizzes, for constructive reading
Fundamental law of thermal radiation: Planck's law. The black body
References
Exclusive to subscribers. 97% yet to be discovered!
You do not have access to this resource.
Click here to request your free trial access!
Already subscribed? Log in!
![](/assets/images/logo-eti-286623ed91fa802ce039246e516e5852.png)
The Ultimate Scientific and Technical Reference