High-Precision and High-Resolution Measurements of Thermal Diffusivity and Infrared Emissivity of Water–Methanol Mixtures Using a Pyroelectric Thermal Wave Resonator Cavity: Frequency-Scan Approach

The thermal diffusivity and effective infrared emissivity of water–methanol mix-turesweremeasuredat atmospheric pressure andambient temperature using apyro-electric thermal-wave resonator cavity. The applied frequency-scan method allows keeping the cavity length fixed, which eliminates instrumental errors and substan-tially improves the precision andaccuracyof themeasurements.A theoreticalmodel describing conduction and radiation heat transfer in the cavity was developed. The model predictions and the frequency-scan experimental datawere compared, show-ing excellent agreement. The measurements were performed for methanol volum