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 said shell (1);

• wherein
• said coil (4) is fixed on a bottom of said shell (1) and is located below said permanent magnet assembly;
• said shielding layer (5) is arranged between said permanent magnet assembly and said coil (4);
• one end of said wire (6) is connected to said coil (4) while the other end thereof is connected to a power supply and signal plug (7);
• said permanent magnet assembly comprises a third permanent magnet (12) and a fourth permanent magnet (13) wherein the fourth permanent magnet (13) is arranged side by side with said third permanent magnet (12) and located on two sides of a width direction of said third permanent magnet (12), and said fourth permanent magnet (13) and said third permanent magnet (12) are arranged at intervals and said intervals are made of non-conducting non-magnetic bushing material (9);
• and
• an upper end faces of said third permanent magnet (12) and said fourth permanent magnet (13) realize magnetic circuit closing by means of a magnetic circuit closing element (8).