Fotric 320F Series, User Manual

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more energy than objects with a lower temperature. Infrared radiation an object
absorbs is usually transformed into thermal energy of its own and gets re-
emitted. Therefore, an object’s emissivity is linked to its absorptivity.
Radiation
Any object with a temperature higher than absolute zero is continuously
radiating heat in the form of an electromagnetic wave. The capacity of emitting
energy is called emissivity.
Conduction
Heat is always transferring from objects with higher temperatures to objects with
lower temperatures. Conduction is the primary way of heat transfer in solids.
Convection
The process of transferring heat due to the movement of fluid is called
convection and is usually caused by an imbalance of temperature.
Atmospheric windows
A range of wavelengths over which there is relatively little absorption of radiation
by atmospheric gases is called ‘atmospheric window’. The atmospheric window of
the infrared band locates between 7~14µm, where the atmospheric transmittance
is most stable. Therefore, thermal measurement on this window is particularly
accurate.
Blackbody radiator
Black body radiator refers to objects that absorb all incident radiation and
convert them into their energy to emit outwards, during which process there is
no occurrence of either reflection or transmission. A blackbody’s emissivity ε= 1.
A blackbody is an ideal object that does not exist in the real world. Blackbodies
used for research and calibration are close approximations with emissivity close
to 1 (usually greater than 0.95)
Colored body radiator