Distribution temperature calculations by fitting the Planck radiation curve to a measured spectrum

A method of calculating distribution temperatures by numerically fitting Planck radiation curves to measured spectra is discussed. Numerically generated spectra were used to test the method and to determine the sensitivity to noise and the effects of linear emissivity changes. A comparison with the multiple-pair method of calculating color temperature as described in a previous paper [Appl. Opt. 27, 4073 (1988)] is presented. It was found that the method described here is ~ 2 times less sensitive to noise than the previously described method. Nonconstant emissivity (the linear model) produces the same effect on calculated distribution temperatures regardless of the calculating method.