METHOD AND APPARATUS FOR ON-LINE MONITORING THE TEMPERATURE AND VELOCITY OF THERMALLY SPRAYED PARTICLES

摘要

A method and an apparatus for monitoring simultaneously the temperature and velo city of a thermal spray jet. The apparatus has a sensor head directed at the jet, the sens or head having two optical fibers carrying radiation from the jet to a remote detection unit wh ich comprises two or three photodetectors. The radiation carried by the separate optical fiber s is filtered at two different wavelengths before being passed to the photodetectors. The tempera ture of the jet is determined by analyzing the ratio of the energy radiated at the two wavel engths. The velocity of the jet is determined, knowing the distance between the fibers, by m easuring the time delay between the signals carried by the separate fibers using cross-correl ation.