ACCURATE PYROMETRY WITH MICROSECOND TIME RESOLUTION

The development of pyrometry with time resolution in the microsecond range is required by high-speed thermophysical property experiments with millisecond duration. The general design criteria of a high-speed pyrometer with such a resolution are discussed and the contribution of several parameters is analysed to optimise the pyrometer performance with respect to the temperature-time characteristic of the event to be measured. Salient features of a pyrometer built on the basis of these criteria are described, with the details of the procedures necessary for its calibration. Monochromatic operation either near 0.65 mu m or near 1 mu m and a response time to a step input of 5 mu s make the instrument adequate for measuring temperature with a time resolution in the microsecond range. Emphasis is placed on the inaccuracy of temperature measurements made with the instrument.