Reconstructing Internal Temperature Distributions from Ultrasonic Time-of-Flight Tomography and Dimensional Resonance Measurements

Two ultrasonic techniques for reconstructing the internal temperature distribution in metal bodies-time-of-flight tomography and dimensional resonance profiling-are described. An analysis of the tomographic reconstruction of temperature (including ray refraction effects) in a cylindrical body is presented together with initial experimental results. Dimensional resonance profiling is a new technique that allows the reconstruction of a one-dimensional distribution of temperature in a structure from measurements of its resonant frequencies. While time-of-flight tomography is well suited for measuring temperature in a cylindrical geometry, a combination of dimensional resonance and (a restricted form of) tomography is the best method for measuring temperature profiles in the more practically important rectangular slab geometry.