Method and apparatus for emissivity independent self-calibrating of a multiwavelength pyrometer

Abstract

Self calibrating a pyrometer includes taking two different temperatures thereby generating two voltage spectra, calculating the spectra ratio R of the two voltage spectra, determining the slope of the plot of the logarithm of the spectrum ratio versus c.sub.2 /.lambda. to arrive at a relationship between T.sub.1 and T.sub.2, solving for T.sub.1 within the spectra ratio, and arriving at a value for T.sub.2 by substituting experimentally measured values for R into the spectra ratio equation. This method is then repeated for the determination of T.sub.2. The pyrometer calibration constant h.sub..lambda. can then be determined by dividing the measured voltage spectra by the planck function at the known temperature (i.e., T.sub.1 or T.sub.2). Measurement of subsequent temperatures can now be determined by measuring the voltage spectra and dividing by the calibration constant h.sub..lambda. which will result in a planck function L.sub..lambda. (T) which can be solved to yield the surface temperature.

Dependencies are inferred from the claim text.