Thermal radiation

1.

Determination of the Stefan-Boltzmann
constant using an optical pyrometer
with a disappearing thread of the
Oppir-09 type
Prokhorova Angelina
Popova Polina
Porfiriev Mikhail

2.

THERMAL RADIATION

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BLACK BODY
A black body is a body
that absorbs any radiation
falling on it.

6.

KIRCHHOFF 'S LAW
The ratio of the spectral exitance of any body to
its spectral hemispherical absorptance is the
same for all bodies
The spectral exitance (r) is the ratio of the radiant
emittance in a narrow part of the spectrum (dRe)
to the width of this part, where radiant emittancea quantity measured by the radiation flux emitted
by a unit of body surface in all directions.
Spectral hemispherical absorptance is the ratio of
the radiation flux absorbed by a given body to the
incident monochromatic flux.

7.

STEFANBOLTZMANN LAW
WIEN’S LAW
The wavelength, which accounts for the maximum
energy of the radiation of a black body, is inversely
proportional to the absolute temperature:
The radiant emittance of a perfectly black body is
proportional to the 4 degrees of absolute temperature
The maximum value of the spectral density of the
energy luminosity of a blackbody is proportional to the
fifth degree of absolute temperature.

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Thanks for your
attention!