Theory and Methods of Optical Pyrometry

Report reviewing the theoretical methods of optical pyrometry and the application of these methods at the National Bureau of Standards in realizing, maintaining and distributing the International Practical Temperature Scale above 1063 oC is presented. In the theoretical presentation, the concepts of effective and mean effective wavelengths are introduced, and various equations relating these parameters to each other and other physical quantities are derived. The methods presentation discusses important features of precision visual optical pyrometers, experimental procedures, and results of primary and secondary calibrations of optical pyrometers.