This paper reviews the state of phosphor thermometry, focusing on developments in the past 15 years. The fundamental principles and theory are presented, and the various spectral and temporal modes, including the lifetime decay, rise time and intensity ratio, are discussed. The entire phosphor measurement system, including relative advantages to conventional methods, choice of phosphors, bonding techniques, excitation sources and emission detection, is reviewed. Special attention is given to issues that may arise at high temperatures. A number of recent developments and applications are surveyed, with examples including: measurements in engines, hypersonic wind tunnel experiments, pyrolysis studies and droplet/spray/gas temperature determination. They show the technique is flexible and successful in measuring temperatures where conventional methods may prove to be unsuitable.

This paper reports on the correlation between gas flow and plasma behaviour in the outflow of a micro-atmospheric pressure plasma jet operating in helium using both 2D optical imaging and Schlieren photography. Schlieren photography shows that the helium outflow changes from laminar to turbulent conditions after distances between 20 and 50 mm from the nozzle. Above a flow rate of 1.4 slm, the length of the laminar region decreases with increasing flow rate. However, by contrast the visible plasma plume increases in length with increasing flow rate until its extension just exceeds that of the laminar region. At this point, the plasma becomes turbulent and its length decreases. Exposing polystyrene (PS) samples to the plasma jet significantly alters the water contact angle in a defined area, with the hydrophobic PS surface becoming more hydrophilic. This modification occurs both with and without direct contact of the visible glow on the surface. The radius of the treated area is much larger than the width of the visible jet but much smaller than the area of the turbulence on the surface. The treated area reduces with increasing nozzle–substrate distance.

The purpose of this paper is to demonstrate a novel technique for imaging 2D temperature distributions using rise-time analysis from luminescence exhibited from a Y 2 O 3 :Eu thermographic phosphor. In phosphor thermometry, it is usually the lifetime-decay temporal response that is used to determine temperature; the rise component is usually ignored. We claim to be the first to obtain 2D thermal imaging using the rise-time response. This was demonstrated using flame impingement experiments. A 1 Mfps state-of-the-art high-speed Shiamadzu Hypervision camera was used to capture the phosphors' temporal response, and was later processed in Matlab. The resulting thermal map clearly indicated a variation in temperature and showed an uncertainty of 20% at 400 • C. This is relatively high, and suggestions to improve this are proposed. A calibration of rise time versus temperature is taken between 200 and 700 • C. This paper builds on previous work in the field, and the results presented in this paper confirm the extended temperature sensing capability of Y 2 O 3 :Eu using rise-time characteristics.

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There are numerous ways in which pressure-sensitive paint can be applied to a surface. The choice of substrate and application method can greatly affect the results obtained. The current study examines the different methods of applying pressure-sensitive paint to a surface. One polymer-based and two porous substrates (anodized aluminum and thin-layer chromatography plates) are investigated and compared for luminescent output, pressure sensitivity, temperature sensitivity and photodegradation. Two luminophores [tris-Bathophenanthroline Ruthenium(II) Perchlorate and Platinum-tetrakis (pentafluorophenyl) Porphyrin] will also be compared in all three of the substrates. The results show the applicability of the different substrates and luminophores to different testing environments.

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