Abstract: A method and apparatus for casting molten metal in an opaque container and for determining the level of the metal within the container. This is accomplished by locating a strain sensing transducer over the container and metal, and sending a current pulse from the transducer along a wire located in the tube connected to the transducer and extending toward the vessel and molten metal. A permanent magnet is located on a stem connected to a float within the container, the float being effective to rest and float on the upper level of the molten metal within the container. A current pulse is sent along the wire from the transducer, which pulse produces a magnetic field, and which field interacts with a magnetic field of the permanent magnet. The interaction of the two fields exerts a strain on the tube, which strain is sensed by the transducer.