Abstract: A level control system for controlling the thickness of a work material in a slurry form cast upon a moving belt includes a fluid reservoir disposed above the belt, a sensor lens assembly for sensing the slurry height within such reservoir, and a control valve for adding slurry to the reservoir. A lens disposed near the moving belt and above the reservoir is coupled by fiber optics to a remote sensor amplifier for detecting the height of the slurry. A control circuit responsive to the light sensor regulates the flow rate of the slurry through the control valve.

Abstract: A method for controlling a molten metal pouring operation is disclosed which works in the presence of unusual pouring conditions such as typically encountered in aluminum casting and utilizes a laser type sensor, for example a triangulation based light section device, to monitor differences between a reference surface and the molten metal in a mold.

Abstract: A method of controlling the level of molten metal in a mold for continuous casting by using a molten metal level control system incorporating a molten metal level controller in the control loop thereof, which comprises damping selectively the predetermined frequency of frequencies of periodical molten metal level fluctuations through a notch filter installed in the control loop. The control loop preferably includes the phase compensation calculation part for compensating the phase delay of the stopper opening position control signal for adjusting the amount of the molten metal to be fed to the mold. The control apparatus in the control loop comprises a molten metal level senser, an FFT analyzer, an automatic tuning device for dealing with the results of the FFT analysis, a molten metal level controller and a notch filter.