Self-normalized photoacoustic technique for measurement of thermal diffusivity for metals

The analytical solution for the one-dimensional heat diffusion problem involving an harmonic heat source in a single layer, in the surface absorption limit, was applied to provide a self-normalized photoacoustic methodology for the measurement of thermal diffusivity for metals. The analytical procedure involves the photoacoustic phase lag, ΔΦ, between the rear and front configurations and relies on the experimental localization of the value of the modulation frequency where cos(ΔΦ) takes its first zero. Some computer simulations are provided to show the feasibility of the presented methodology, which was experimentally tested by measuring the thermal diffusivity of four metal samples.