APPARATUS FOR THE DETECTION AND MEASUREMENT OF PARTICULATES IN MOLTEN METAL

A probe for insertion into molten metal to detect and measure particulates suspended therein includes an inner tube of an electrically insulated materi al forming a metal receiving chamber, the tube having an orifice to permit molten metal to flow into the chamber. A first electrode extends into the chamber for engaging metal within the chamber and a second electrode surrounds at least a portion of the inner tube for engaging molten metal outside of the chamber. The electrodes may be connected to a measurement device for establishing a current path through the electrodes and passing through the orifice for measuring changes in the electrical potential produced by the passage of particulates entrained in th e molten metal passing through the orifice. An outer sheath of heat resistant material surrounds a portion of the second electrode and a gas passageway extends out of the inner tube for connecting to a vacuum source to create a pressure differential within the chamber for facilitating the flow of molten metal through the orifice. A liquidus depressing material is in the chamber for alloying with molten metal entering the chamber to lower the liquidus temperature of the molten metal and permit a longer time period for detecting and measuring particulates in the molten metal.