Abstract: An apparatus for measuring the thickness of a slag layer on a metal melt in a metallurgical vessel comprises a first inductive eddy current sensor which indicates the distance of the apparatus from the metal melt as it is moved toward the melt. A second sensor detects when the apparatus reaches a predetermined distance relative to or contacts the slag layer and triggers the inductive eddy-current sensor when such distance is attained. The sensors are arranged in predetermined spatial relation and the thickness of the slag layer is determined by an evaluation device which analyzes the received signals. The apparatus permits measurement of the thickness of the slay layer without the need of additional equipment (e.g. mechanical lance movement or distance measurement).

Abstract: A contact free flow meter for determining the velocities and/or flow directions of electrically-conductive fluids is disclosed. At least one primary magnetic field is arrayed generally perpendicular to the flow path, the field having strength gradients extending along the flow path. At least two magnetic field sensors are spaced apart in the direction of the flow path the sensor being responsive to the magnetic field. The device is capable of functioning notwithstanding electrically-conductive material such as pipe walls interposed between the fluid and the meter.