Overview of Measurement Technique

Our thermal property measurement procedure generally follows that of the ASTM standard D 5334-00 [2004] for needle probe thermal conductivity measurements, a technique originally developed by von Herzen and Maxwell [1959]. A constant current is supplied to a heater wire in the needle probe. The heater wire's output causes a temperature change in the sample. This change is measured as a function of time by the thermistor bead within the needle probe. Based from the time-dependent temperature change, the thermal properties of the sample can be calculated.

The following pages describe the calculations for:

• Thermal conductivity, λ
• Thermal diffusivity, κ
• Specific heat, c_p
• Needle Probe Calibration (required for calculating κ and c_p)