The Modified Transient Plane Source (MTPS) technique employs a one-sided, interfacial heat reflectance sensor that applies a momentary constant heat source to the sample. The most common application of the MTPS method is employed by C-Therm’s TCi Thermal Conductivity Analyzer. (Disclosure: C-Therm Technoogies Ltd. is a partner in Thermal Analysis Labs)
Thermal conductivity and effusivity are measured directly, providing a detailed overview of the thermal characteristics of the sample.
A known current is applied to the sensor’s spiral heating element, providing a small amount of heat. This results in a rise in temperature at the interface between sensor and sample, which induces a change in the voltage drop of the sensor element. The rate of increase in the sensor voltage is used to determine the thermo-physical properties of the sample. The thermo-physical properties are inversely proportional to the rate of increase in the sensor voltage.The voltage rise will be steeper for more thermally insulative materials (foam). Results are displayed on the system’s software in real-time.
Appropriate for liquids, powders, pastes and solids under 500 W/mK.