Significance

• Pyrometers use an optical technique similar to human vision. Considering that all materials radiate the same amount of light and color at a certain temperature, pyrometers are designed on this theory. Using emissivity, or radiation efficiency of each material, pyrometers read how bright a material is and calculate brightness into a temperature.
  
  

Factors

• True temperatures are formulated into a mathematical equation depending on the type of pyrometer used. Because of emissivity changes, errors are produced by radiation emitted, absorbed, and reflected by surrounding entities (walls) and even the target itself.
  
  

Types

• One color pyrometers directly translate color into temperature; the brighter the light, the higher the temperature. Two color pyrometers use two detectors for color differences and then mathematically calculate temperature. A spectropyrometers is a multi-wavelength pyrometer measuring hundreds of colors at once, and turns them into advanced algorithms to determine temperature. There are also total radiation pyrometers, photo electric pyrometers, and disappearing filament pyrometers designed for different applications.