Rare-earth phosphors for remote thermographic applications

Numerous phosphors with rare-earth dopants have emissions that are strongly dependent on temperature and are therefore useful for remote-temperature measurement, especially in moving, confined, or hazardous systems. The emission properties of various phosphors of this type were measured from room temperature to {approximately}1,200{degree}C, along with data relative to their stability under thermal cycling. For practical temperature monitoring applications, thermographic phosphors must remain relatively stable under the conditions they must experience during the measurement. One important consideration then, is any change in fluorescent properties that might accompany temperature cycling. The phosphors that had the most stable behavior under cycling were La{sub 2}O{sub 2}S:Eu, YVO{sub 4}:Eu, Y{sub 2}O{sub 3}:Eu, and YVO{sub 4}:Dy. 7 refs., 11 figs., 1 tab.