Abstract: The trouble free operation of a continuous casting process utilizing a moving electromagnetic field for levitation requires information of sufficient accuracy concerning the position and extent of the solidification front inside the continuous casting die. The method and structure according to the invention for monitoring the solidification process employs signals from at least two sensor coils arranged concentrically around the continuous casting die. These signals are fed to a measuring transducer and processed in an appropriate manner. The configuration of the sensor coils inside the levitation coil generating the moving field is particularly preferred.

Abstract: An electromagnetic ball valve for a flow medium under pressure such as a respirating gas for a respirator which must be adapted to use with a respirator which operates at a high frequency in the range of fifty times the usual frequency. Such ball valve must be employed in the breathing gas supply so as to open and close the supply path and a small volume of gas internal of this apparatus permits this control. The electromagnetically ball valve is arranged with the electromagnetic pole pieces in a sheath and the pole pieces include a flow passage in which a ball moves between a seat and an abutment under the control of a separate electromagnetically controlled pole piece. The seat is cooperative with the ball valve with one connection for the flow medium and the abutment includes a connection for the space around the ball valve under another flow connection. With a delivery side connection through the space around the ball and with a seal on the seat it acts as a NC valve.