A previous procedure to measure thermal diffusivity and thermal conductivity simultaneously using an inverse solution for one-dimensional unsteady heat conduction can be simplified by improving the inverse solution and then clearing the issue left in previous one. The new procedure does not need any time when the temperature change starts at a sensor position and can simply choose a time duration during which the measured temperature change becomes larger than the required accurate temperature change. The measurement is usually completed within 3 minutes until the temperature rise at the thermocouple position reaches a certain temperature level which makes its error level reduce lower than one percent. This method has merit being independent of surface condition except for the requirement of two or three sensing positions in the material. The accuracy of the estimated values is also similar to the error level of sensor at the position.
