Salamander Ceramic Infrared Emitters Technical Manual Page 9

En Español

        Notice in the Planck's Law curves shown on the previous page that the spectral radiancy of the source increases proportionally with the source temperature. In other words, the radiant infrared output from a source increases as the temperature of the source increases. The overall infrared emissions from a given source is equal to the area under the associated Planck's Law curve. By integrating Planck's Law at a given temperature with respect to the wavelength we can calculate the amount of infrared emissions within a given range of wavelengths (See graph below).

        Also notice that as the temperature of the source increases, the peak wavelength of the source becomes shorter. When the temperature of the source becomes too high a noticeable amount of energy is emitted from the source as light. That is, a portion of the energy emitted from the source falls within the wavelengths associated with light. Referring back to the infrared spectrum chart shown on page 7, visible light occurs starting at .40µm and ends at .70µm. The infrared spectrum starts at .70µm and extends to 1000µm. Although the useful range of wavelengths for infrared heating applications occurs between .70µm to 10µm.

Wien's Law:

        Wien's Law gives the wavelength at which the spectral distribution (given by Planck's Law) of the radiation emitted by a blackbody is at a maximum point. Note, however, that according to Plank's Law a range of wavelengths is emitted from a source at a specific temperature! Wien's Law simply gives the "peak wavelength".

            2.898 x 10 ^-3       m K
λm =  ^{__________________________}
                          T _k

Where:
    λm = Peak Wavelength in Meters
    T _k = Temperature in K (Kelvin)
            K = (°F + 460)/1.8

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