Abstract: In a continuous casting apparatus, the level of liquid in the mold is monitored and compared to a desired reference level. A microcomputer examines the resulting error signal and determines the amount of movement of the valve which would be appropriate to correct the detected error. A control pulse is then generated having a duration corresponding to the desired movement distance, and the valve is adjusted accordingly.

Abstract: A method is provided for measuring and controlling the level of an elevated temperature liquid in a container. The method includes converting electrical voltage signals from temperature sensing means spaced along a wall of the container to digital form. The converted signals are periodically scanned in elevation sequence. From the scanned signals the location is determined of the uppermost sensing means having a signal value of sufficient magnitude to lie below the liquid level. A fraction, F, of the spacing between that sensing means and the next above sensing means is calculated at which the measured liquid level lies. The fraction determined is a function of the converted signal value, Sn-1, a converted signal value, Se, at an estimated location of the liquid level and, So, a converted signal value sufficient to cause the fraction, F, to be at or near zero in value immediately prior to imminent changes in the location of the uppermost sensing means determined to lie below the liquid level.