Patent ID: 7976215

Claim:
An apparatus for measuring thermal diffusivity using the flash method, the apparatus comprising: a laser generator for generating a flash beam; a measurement sample having graphite layers formed on front and rear surfaces thereof and interposed in a path of the flash beam, the front surface being proximate to the laser generator and the rear surface being remote therefrom; an infrared sensor disposed at the rear of the measurement sample for measuring a temperature and time at the rear surface of the measurement sample from heat dissipated from the measurement sample, the infrared sensor generating an output signal as a function of said temperature and time; and operation means coupled to the infrared sensor for performing an operation based on the output signal of the infrared sensor, the operation means calculating a half time (t s+gr ) 1/2 based on the output signal, said half time being the time required for the occurrence of half of the temperature rise for the measurement sample to reach thermal equilibrium, the operation means calculating a resistance coefficient Gr eff of the measurement sample as a function of said half time, the operation means calculating an apparent graphite thickness l apgr of the measurement sample as a function of said resistance coefficient, the operation means calculating the thermal diffusivity of the measurement sample as a function of said apparent graphite thickness.