Video Thermography Techique for Temperature Measurements of Pulse- Heated Metallic Rods

摘要

A video thermography technique for measuring the surface temperature of metallic rods is described in this report. The technique employs a video camera with charge-coupled devices as the detection elements; it is applicable to materials that can be preheated to form an oxide layer with a stable emissivity. The procedure is illustrated by the measurement of the surface temperature of molybdenum rods that have been rapidly heated to about 800 K by an electrical discharge. The thermal emission profile of the sample is observed with the video camera, and the final surface temperature is inferred from previously obtained calibration data. The time-dependent current through the rod is also measured and used as input in theoretical calculations that describe the coupled transport of electromagnetic fields and heat through the sample. The temperatures predicted by the model calculations are in excellent agreement with the values inferred from the experiments.