Emissive Power for a Blackbody over a Range of Wavelengths

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This Demonstration shows the emissive power for a blackbody over a range of wavelengths, represented by the area under the curve between values and .


Planck’s blackbody radiation law gives the spectral density emitted by a blackbody as a function of wavelength and temperature:


is the absolute temperature of the body, K.

is the first radiation constant: .

is the second radiation constant: m K.

The fraction of the total blackbody emission in a spectral band between wavelengths and , at temperature , is given by the integral:


Contributed by: Rubí Ramírez (August 2022)
Suggested by: Rafael Fernández
With additional contributions by: Tomas Garza and Rafael Fernández
Open content licensed under CC BY-NC-SA






[1] F. Kreith, R. Manglik and M. Bohn, Principles of Heat Transfer, 7th ed., Stamford, CT: Cengage Learning, 2011.

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