Angstrom's method for thermal diffusivity measurements

ID: DFT21.010.00

Above: Example test setup and results.


Angstrom’s method is an effective approach for one-dimensional thermal diffusivity measurements. The main advantage of the method is simplicity and robustness. The method does not require accurate quantification of Joule heating into the sample, thermal resistance between the instrument and the sample, or heat loss to the surroundings. Our approach employs the following methods:

  • Lopze-Baeza et al.’s [1] physical model and IR thermography for temperature detection.

  • Forced convection to obtain relatively uniform convective heat transfer coefficient, as well as to reduce random temperature drift from the ambient environment.

  • Bayesian framework for uncertainty quantification and demonstrated benefits of the datarich IR thermography [2].


This instrument provides quick and accurate thermal diffusivity measurements for various applications, which include materials synthesis and characterization in addition to thermal management and anenhancement, for example, by thin film deposition. Measurements from this instrument can also provide an indication of consistency of methods used in synthesizing or processing materials.

  • Materials synthesis

  • Materials characterization

  • Thin film deposition

  • Thermal management


[1] Lopez-Baeza, E., J. De La Rubia, and H. J. Goldsmid. "Angstrom's thermal diffusivity method for short samples." Journal of Physics D: Applied Physics 20.9 (1987): 1156.

[2] Hu, Yuan, and Timothy S. Fisher. "Accurate Thermal Diffusivity Measurements Using a Modified Ångström's Method With Bayesian Statistics." Journal of Heat Transfer 142.7 (2020).