Pulsed photoacoustic technique for thermal diffusivity determination

摘要

The paper describes an automated facility designed to measure thermal diffusivity of solids by analyzing amplitude spectrum of photoacoustic signal through fast Fourier transform. The facility includes a pulsed laser, a gas-filled microphone cell, digital storage oscilloscope, and a control unit linked to a computer via a parallel interface. The thermal diffusivity coefficient of duraluminium, zinc, and silicon derived from the measured characteristic frequency, which corresponds to the transition from a thermally thin to thermally thick sample coincides with literature data within the experimental error.