Flash Method

Principle

The front surface of the plate-like sample flash the heating light of very short pulse width(~1ms). The surface is uniformly heated, one dimensional heat flow through the sample.
Then, the temperature of the rear surface gradually rises. The thermal diffusivity of the material can be determined by measuring the temperature rise curve.
Thermal conductivity can be calculated from the relation,

λ = ρ C_pα

Where ρ is the density, C_p is the specific heat, and α is the thermal diffusivity.

Related standards

JIS H 7801：2005, JIS R1611:2010, JIS R1667:2005
ASTM E1461-13, ASTM E2585-09, ISO 18755:2005, ISO 22007-4:2008