Infrared and Fiber-Optic Thermometers

Pyrometric thermometers can be of the following types optical (brightness), ratio (two-color), total (wide-band), and narrow-band, whereas the fiber optic designs can be of the light-pipe, black body, dual-wavelength, crystal, gap, and fluoroptic variety. Their temperature ranges are from -40 to 4,000°C (-40 to 7,000°F), and their errors range from 0.25% to 2% FS. 

It was only a few hundred years ago that physicists abandoned the view that heat is a substance and accepted that it is a form of energy that is transferable from one material to another by conduction, convection, or radiation. Since that time it has been discovered that all materials, at all temperatures, including down to near absolute zero, radiate electromagnetic energy, which 

Post-Oil Energy Technology After the Age of Fossil Fuels 

The amount of thermal radiation leaving an object depends on the temperature and emittance of that object. If the object is a perfect emitter (a black-body), its emittance is unity. The emissivities of almost all substances are known (Table 3.167), but emissivity is only one component in determining 

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