FLIR ThermaCAM P20 - Figure 18.5 Wilhelm Wien

of-thumb 3 000/T μm. Thus, a very hot star such as Sirius (11 000 K), emitting
bluish-white light, radiates with the peak of spectral radiant emittance occurring
within the invisible ultraviolet spectrum, at wavelength 0.27 μm.
10399403;1
Figure 18.5 Wilhelm Wien (1864–1928)
The sun (approx. 6 000 K) emits yellow light, peaking at about 0.5 μm in the middle
of the visible light spectrum.
At room temperature (300 K) the peak of radiant emittance lies at 9.7 μm, in the
far infrared, while at the temperature of liquid nitrogen (77 K) the maximum of
the almost insignificant amount of radiant emittance occurs at 38 μm, in the ex-
treme infrared wavelengths.
18.3 – Blackbody radiation
Publ. No. 1 557 536 Rev. a35 – ENGLISH (EN) – January 20, 2004 91