Location

La Jolla, CA

Start Date

1-1-1998 12:00 AM

Description

Thermal wave interferometry (TWI) for materials characterization is based on detecting the surface temperature variations caused by a modulated heat source at the material surface, and consequently deducing the internal structure from the observed thermal energy propagation properties. The usefulness of the methodology has been accepted for a large variety of measurement problems, including thermal diffusivity determination of materials, coatings thermal properties and thicknesses, detection of laminations, detection of bulk defects, etc. A typical TWI system is shown in Figure 1. The surface is illuminated with square-wave modulated uniform laser light and the thermal response is observed radiometrically with an IR-detector. Measurements of the relative amplitude of the surface and the phase difference between the excitation and the surface temperature variation are obtained.

Book Title

Review of Progress in Quantitative Nondestructive Evaluation

Volume

17A

Chapter

Chapter 3: Signal Processing and Image Analysis

Section

Imaging and Reconstruction

Pages

831-836

DOI

10.1007/978-1-4615-5339-7_107

Language

en

File Format

application/pdf

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Jan 1st, 12:00 AM

Direct Numerical Approach for Analyzing Thermal Wave Interferometry Data

La Jolla, CA

Thermal wave interferometry (TWI) for materials characterization is based on detecting the surface temperature variations caused by a modulated heat source at the material surface, and consequently deducing the internal structure from the observed thermal energy propagation properties. The usefulness of the methodology has been accepted for a large variety of measurement problems, including thermal diffusivity determination of materials, coatings thermal properties and thicknesses, detection of laminations, detection of bulk defects, etc. A typical TWI system is shown in Figure 1. The surface is illuminated with square-wave modulated uniform laser light and the thermal response is observed radiometrically with an IR-detector. Measurements of the relative amplitude of the surface and the phase difference between the excitation and the surface temperature variation are obtained.