Multiple Shots Averaging in Laser Flash Measurement

The knowledge of the thermal properties of materials is a key resource for the correct design of industrial components. The laser flash method is a well-known procedure to determine the thermal diffusivity of a wide range of materials. However, in some cases there is the need of limiting the input power, or measuring materials with high thermal capacity, or investigating thick samples. Under these circumstances, the expected signal-to-noise ratio can reach extremely low values. To solve this issue, the existing laser flash apparatus has been improved, creating a new control and data acquisition system that is able to repeat multiple times the emission of the laser impulse and the measurement of the thermal response of the specimen. This gives the possibility of averaging several measurements, leading to a decrease of the noise. The experimental validation on different samples shows the feasibility of the proposed setup, that makes it possible to work with low power inputs.