The Analyst · 1977 · 113 citations · 0 references
EngineeringMaterials EngineeringMaterials ScienceHeat TransferThermal AnalysisThin FilmsHeat Transfer AnalysisHeat Transfer In SolidsTemperature MeasurementThermal DiffusivityThermal Properties Of MaterialsThin Film Thermal PropertiesSurface Temperature DistributionThermal Conductivity MeasurementsThermal Diffusivity EstimationThermal Diffusivity In PolymersThermal Diffusivity In Thin FilmsThermal Diffusivity MeasurementThermal Diffusivity Of SolidsThermal Sensing
A simple apparatus is described that permits heat-flow characteristics of a sample to be determined, and its application to the determination of the thermal diffusivity or thickness of polymer films on a copper substrate is reported. The apparatus utilises the optoacoustic effect in which periodically interrupted radiation is absorbed by a solid sample to give rise to a similar periodic variation of the pressure of the air in contact with the sample surface in a closed cell. The amplitude and phase of the observed optoacoustic signal depend on the thermal diffusivity and thickness of the material irradiated.