Electromagnetic ultrasonic double-wave transducer

An electromagnetic ultrasonic double wave transducer, comprising a shell (1), and a permanent magnet assembly, a coil (4), a shielding layer (5), and a wire (6) which are provided in the shell (1);

• said permanent magnet assembly comprises a first permanent magnet (2) and a second permanent magnet (3) sleeved on the first permanent magnet (2), the second permanent magnet (3) having a circular shape;
• the magnetizing directions of the first permanent magnet (2) and the second permanent magnet (3) are perpendicular to a bottom of the shell (1), and magnetic field directions of the first permanent magnet (2) and the second permanent magnet (3) are opposite;
• a non-conducting non-magnetic bushing material (9) is only disposed in between the first permanent magnet (2) and the second permanent magnet (3), and upper end faces of the first permanent magnet (2) and the second permanent magnet (3) realize magnetic circuit closing by means of a magnetic circuit closing element (8);
• said coil (4) is fixed on the bottom of said shell (1) and is located below said first permanent magnet (2);
• said shielding layer (5) is provided between the lower end of said first permanent magnet (2) and said coil (4) and below said second permanent magnet (3);
• one end of said wire (6) is connected to said coil (4), and the other end is connected to a power supply and signal plug (7),
• wherein the electromagnetic ultrasonic double wave transducer is adapted for simultaneously exciting vertical downward-transmitted ultrasonic transverse waves and ultrasonic longitudinal waves on a surface of a conductive or magnetic testing subject.