METHOD FOR MEASURING THICKNESS OF SOLIDIFIED LAYER

摘要

PURPOSE:To measure the thickness of a solidified layer in a billet to be measured in accordance with the voltage induced in a secondary coil by the magnetic field intersecting with the solidified layer and a molten steel by disposing a detecting head provided with a primary coil and secondary coil in proximity to said billet and impressing an AC voltage on the primary coil. CONSTITUTION:A detecting head consisting of an H-shaped core 21 as well as a primary coil 22 wound on the core 21 and a secondary coil 23 is disposed near a billet 1. The coil 23 is constituted of a measuring coil 23a near the billet 1 and a reference coil 23b which is in the position apart from the billet and does not include the billet 1 in its magnetic path. The AC magnetic field generated when an AC voltage is impressed on the coil 22 intersects with the billet 1. Since the coil 23 consists of the differentially connected coil 23a and coil 23b, the output thereof is of the value corresponding to the thickness of the solidified layer 1a of the billet 1.