The 3-omega technique has been established at TPUC for direct measurement of thermal conductivity. This technique was originally reported by David Cahill in 1989. It utilizes an AC heating current and a lock-in amplifier to directly measure thermal conductivity of dielectric materials. A small line heater is put on the sample surface by sputtering through a mask or photolithography. It acts as both heater and thermometer. The 3-omega method is fast and accurate compared to other thermal conductivity measuring techniques. Furthermore, the 3-omega technique can be used to measure thermal conductivity of coatings and thin films.

Features:

• Direct thermal conductivity measurement
• Labview^TM controlled data acquisition
• Temperature range of -190 to 500^oC
• Heating frequency up to 10 KHz

Applications:

The 3-omega technique is used to measure thermal conductivity of materials such as glasses and non-electrically-conducting ceramics. Samples with complex geometry can be tested as long as a heater/thermometer can be place on the surface. Since the thermal wave measurement depth is controlled by the heating frequency, thermal conductivity of coatings and thin films can be studied.