The Multichannel Infrared-Red Temperature Micro-Analyzer (MIRTMA) system is used to experimentally demonstrate the feasibility of a method of multiwavelength pyrometry using least-squares fitting analyses. The MIRTMA is a prototype instrument capable of monitoring temperatures above 1100 K with a spatial resolution of 100 um using spectral radiance measurements at approximately 200 wavelengths in a range of 0.6 to 0.8 um. Demonstrations of this equipment on a heated platinum strip source are described and discussed. The temperature measurements of these sources are generally within 5% of the actual temperature but can be within 1% using certain techniques. Capabilities and limitations of the method and the MIRTMA equipment are presented. The various calibrations used with the technique are also described, particularly with respect to corrections for the nonlinear response of the silicon intensified target (SIT) detector employed. Potential improvements to the instrument based on this work are presented, and it is concluded that the SIT detector should be replaced with a more suitable detector.