A METHOD OF MEASURING PARTICLES IN MOLTEN METAL WITH A LIQUID METAL CLEANLINESS ANALYZER(LiMCA) AND APPARATUS THEREOF

摘要

The present invention provides a method and apparatus for reducing electromagnetic noise pick up in a Liquid Metal Cleanliness Analyzer (LiMCA),used to detect and measure particles in molten metal. An first electrode inserted in the molten metal is electrically insulated from second and third electrodes, also inserted in the molten metal. Molten metal and particles pass between the first electrode and the second and third electrodes through a passage in the electrical insulation. The second and third electrodes have a configuration with respect to the first electrode sufficient to establish symmetrical current loops between the first electrode and the second and third electrodes when a current is supplied to the second and third electrodes. The current is supplied from an ultra-capacitor. Electromagnetic noise in the symmetrical current loops is detected and is added in opposition to reduce the amplitude of the electromagnetic noise.