Strong influence of the surrounding gas in laser-spot lock-in thermography

In laser-spot lock-in thermography, the amplitude of the surface temperature decreases monotonically with the distance to the laser spot. This radial decrease is commonly used to measure the in-plane thermal diffusivity of the sample. However, in the case of thermal insulators, an unpredicted and abrupt slope change appears in the radial profiles. In this work, we first demonstrate that heat conduction to the air surrounding the sample is the cause of this unexpected behavior. Then, we take advantage of this slope change to retrieve simultaneously in-plane thermal diffusivity and conductivity of thermal insulators.

• Publication year

  2023

• Venue

  Journal of Applied Physics

• Publication date

  2023-05-10

• Fields of study

  Not labeled

• Identifiers
  DOI 10.1063/5.0147507
• External record

  Open on Semantic Scholar

• Source metadata

  Semantic Scholar

• No claims are published for this paper.

• No concepts are published for this paper.

• On the Thermal Characterization of Insulating Solids Using Laser-Spot Thermography in a Front Detection Configuration

  2022cited by this paper
• Thermal diffusivity of metals determined by lock-in thermography

  2017cited by this paper
• Measurements of Thermal and Dielectric Properties of Medium Density Fiberboard with Different Moisture Contents

  2013cited by this paper
• Accurate measurements of the thermal diffusivity of thin filaments by lock-in thermography

  2010cited by this paper
• Thermal Physics Concepts: The Role of the Thermal Effusivity

  2006cited by this paper
• Thermophysical analysis of thin films by lock-in thermography

  2004cited by this paper
• On thermal diffusivity

  2003cited by this paper
• THERMAL DIFFUSIVITY OF ANISOTROPIC MATERIALS BY PHOTOTHERMAL METHODS

  1996cited by this paper
• Theoretical analysis of the surface thermal wave technique for measuring the thermal diffusivity of thin slabs

  1996cited by this paper
• Three‐dimensional photothermal radiometry for the determination of the thermal diffusivity of solids

  1995cited by this paper
• Remote measurement of in‐plane diffusivity components in plates

  1987cited by this paper
• Photothermal measurements using a localized excitation source

  1981cited by this paper

• A thermo-optical plane source method to measure thermal conductivity.

  2025cites this paper