The development of an ultrasonic sensor for determination of the cleanliness of liquid metals

After briefly reviewing the early work in liquid iron and steel, the paper concentrates on the more recent work in aluminum and some of its industrially important alloys. Considerable progress has been made in measuring and monitoring the cleanliness of melts, but in the laboratory and in plant trials involving pressure die casting and the direct casting of billets, The principles developed are directly applicable to liquid steel.