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 velocity of a thermal spray jet. The apparatus has a sensor head directed at the jet, the sensor head having two optical fibers carrying radiation from the jet to a remote detection unit which comprises two or three photodetectors. The radiation carried by the separate optical fibers is filtered at two different wavelengths before being passed to the photodetectors. The temperature of the jet is determined by analyzing the ratio of the energy radiated at the two wavelengths. The velocity of the jet is determined, knowing the distance between the fibers, by measuring the time delay between the signals carried by the separate fibers using cross-correlation.