This paper deals with the effect of magnetic bias of Acoustic Vibration Element using Giant magnetostrictive material (AVEG) which is a low frequency transducer for an man acoustic tomography system. By measurement of magnetostriction characteristics, it is shown that the magnetic bias by magnet is a suitable value and the dynamic range must be less than I= ± 1[A].
The authors analyzed the magnetic circuit of AVEG and calculated the value of magnetic bias field.
And the structure of the magnetic circuit was evaluated with the next distinctive parameter. variation rate of magnetic dux density in the vibrator, effective rate of flux, and sensitivity of magnetostriction.
