a device for measuring the inside dimensions of a cast iron mold includes a measuring device movably arranged inside the cast iron mold on one or several guide rails . the measuring device comprises a rim with plates , each of which forms a capacitor together with an adjacent portion of the mold wall . an electronic unit for generating and subsequently processing signals corresponding to the capacitances of the separate capacitors provides an indication of the interior dimensions of the mold , based upon the capacitance measurements .