Apparatus for detecting defects in a magnetic disk includes a read head including multiple read elements for reading multiple tracks of the disk. Sets of scrambled binary values are received. According to the method of the present invention having the above mentioned constitution and the apparatus thereof, it is possible to separate only pure uranium metal with a high capability from the spent metal nuclear fuels conveniently and economically. An important application of the invention is the provision of a convenient, non-intrusive, low-cost device for field measurement of pressure in drip irrigation systems, without installing special fittings or puncturing the tubing. In general, bond elements in the interior of the bond pattern are closer together than bond elements proximate the side edges of the bond pattern. A sensorless drive operation circuit calculates by operation a zero cross point of a voltage of a position detection phase at the next interval, using time information measured based on an output signal from a comparison circuit at the previous interval and the present interval.