Abstract
An automated technique for measuring an instantaneous, two-dimensional temperature distribution in water has been developed with a digital image processing system. The thermal field is visualized by laser-induces fluorescence of Rhodamine B. The fluorescence of Rhodamine B decreases with temperature increase. A normalized calibration curve, which is not affected by laser intensity, concentration of Rhodamine B and optical configuration, can be obtained. Uncertainty intervals associated with the present technique are systematically evaluated. A steady temperature field in a rectangular enclosure is measured by the present technique. The instantaneous temperature profile measured shows good agreement with both the analytical solution and the result measured by thermocouples within the experimental uncertainty. An unsteady temperature field is also measured. The mean temperature profile is in good agreement with the result of MIYATA (1978).
