Fluorescent Thermometry

At the early stages of development, the lack of a convenient and economic excitation modulation scheme has limited the use of such a phase shift technique in fluorescence thermometry. Now with the wide availability of cheap and easily modu-... 

Perhaps the first detailed discussion of such a technique in fluorescent thermometry (shown in Figure 11.10) was given by Zhang et al. in their work(36) based on both mathematical analysis and experimental simulation. Examples of the electronic design of the corresponding system and the application of the technique in a ruby fluorescence-based fiber-optic sensor system are also listed. This shows that there is no difference in the measurement sensitivity between a system using square-wave modulation and one using sinusoidal modulation. However, the former performs a little better in terms of the measurement resolution. 

Fiber optic fluorescence thermometry can provide several quite flexible approaches to access the required measurement regions. The temperature probes can be... 

Cross-Referencing of Fluorescence Thermometry with Blackbody Radiation Pyrometry... 

In summary, the use of fluorescence lifetime monitoring for temperature sensing at high temperatures is based on the phenomenon of thermal quenching of fluorescence, while this phenomenon is j u st the very obstacle that blocks the extending of the measurement further into higher temperatures. Therefore, fluorescence thermometry is intrinsically more effective for measurement within moderate temperature regions, due to this fundamental nature of the fluorescence emission itself. 

The work has shown the diversity of fluorescence-based thermometry schemes, materials, signal processing arrangements, and applications. In addition, a close agreement with theoretical predictions on material performance gives confidence to the assessment of new materials for such uses. Probe sizes are potentially smaller and more convenient due to optical source and detector developments. Thus the future for fluorescence thermometry is bright, with the expectation of a range of new ideas in the field in the future. 

Two techniques, which appear well suited to the diagnostic probing of practical flames with good spatial and temporal resolution, are coherent anti-Stokes Raman spectroscopy (CARS) and saturated laser fluorescence. The two techniques are complementary in regard to their measurement capabilities. CARS appears most appropriate for thermometry and major species concentration measurements, saturated laser fluorescence to trace radical concentrations. With electronic resonant enhancement (6), CARS may be potentially useful for the latter as well. Fluorescence thermometry is also possible (7, 8) but generally, is more tedious to use than CARS. In this paper, recent research investi-... 

Galvanneal steel is an important material widely used in the production of automobiles. The accurate determination of temperature of galvanneal sheet during manufacture is a critical problem, which has recently been addressed with fluorescence thermometry. In the galvanneal process, steel strip is dipped into a zinc... 

Clearly, the problem of surface emissivity is circumvented by fluorescence thermometry. A phosphor-deposition device applies the phosphor, under command from a control computer. As seen in Fig. 5, this deposition takes place several feet underneath the... 

Fluorescent thermometry involves the use of a fluorescent dye, whose fluorescence intensity is a strong function of temperature, to infer the temperature of a fluid or surface. The dye is dissolved in a fluid of interest, or coated on a surface, and is excited to fluoresce by incident light. The fluoresced light is recorded with a CCD camera, and variations in its intensity are proportional to variations in the local temperature. 

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