Temperature Distribution Measurement of Hot Solid Wall Using a Laser-induced Fluorescence Technique

Abstract

A non-intrusive, high spatial and temporal resolution thermal imaging system based on the fluorescence properties of a dysprosium-doped yttrium-alminum-garnet (Dy^<3+> : YAG) thermographic luminescent material has been developed. The solid surface of a test piece is excited by the third harmonic 355nm beam of a pulsed Nd : YAG laser. The resulting fluorescence emission intensities of 456nm and 496nm peaks in the spectra are acquired using an image-intensified charged coupled device camera. The correlation of the ratio of the acquired peak intensities with temperature is obtained measuring the fluorescence of the test piece in an electric furnace with thermocouple calibration. Temperature measurements of a test piece heated by an impinging jet flame demonstrate the feasibility of this technique for general heat transfer studies involving significant unsteadiness and transient phenomena.