Particle Temperature Measurement in the Thermal Spray Process

Particle temperature is a fundamental parameter in the thermal spray process. The measurement of particle temperature usually relies on the measurement of the radiance of the hot, incandescent, particles in two or more wavelength or color bands. Measurement techniques can be categorized as single particle and ensemble methods. Single particle methods use high-speed pyrometry to estimate the temperature of individual particles. The mean and standard deviation of the particle temperature distribution can then be obtained from observations of sufficient numbers of individual particles. Ensemble methods observe large numbers of particles simultaneously and yield an estimated mean temperature directly, but cannot provide information on the shape or width of the particle temperature distribution. Both techniques have inherent errors, strengths, and limitations that are examined and discussed.