Incandescent solids at temperatures above 1500 K radiate sufficient energy to allow optical pyrometry with a precision of 2 K or less in 1 msec. An instrument system has been built which achieves accuracy of a few kelvins. The sensitivity is 0.4 K when making 1200 measurements/sec near 2000 K or it can be increased as required to 0.01 K with a measurement rate of 1/sec. The system permits dynamic measurement of high temperature thermal properties of refractory metals with better accuracy than has been obtained by methods using slow heating.