Review of Temperature Measurement Techniques

Phase change phenomenon involves instantaneous variations of the local heat transfer, which is coupled to the unsteady fluid currents overlying the surface. An example is the sessile drop, which is of interest in several fields including coating, combustion, and cooling facilities. Understanding of these mechanisms requires fine spatial and temporal measurements, which is essential for applications associated with design optimization and safety consideration of a process. Such consideration is crucial within the operations of boilers, for instance, where the evolved heat flux is restricted by the boiling crisis. This operational regime is often associated with equipment failure. Within the miniaturized electronics applications such as transistors, high heat fluxes up to 200 W/cm2 can be liberated from such instruments, where a low wall superheat is desired with respect to the cooling fluid. Thus, operating within the correct boiling regime becomes paramount in the thermal management of the operating equipment [1-4]. In addition, some of the proposed models are not well validated due to the limited resolution of the available data, which might bring about a misinterpretation of the phase change phenomenon under study. Such situations can be encountered with respect to models based on point measurements, which cannot resolve fine spatial resolutions associated with phase change phenomenon [5-6]. In the current paper, some of the relevant temperature measurement techniques are provided, which include point measurement techniques and IR thermography. A review of fluorescing materials and their usage within temperature measurement applications are given by the end of the paper.