Magnetostriction harmonics measurement using a double piezoelectric transducer technique

The measurement of magnetostriction by the double-transducer technique has advantages of flexibility and sensitivity but is limited by sensitivity variations and phase shifts between transducers. This paper analyses technique limitations and shows how they can be overcome in a practical measurement of magnetostriction harmonics. The apparatus is sufficiently accurate to resolve a relative movement of 2 nm with a base noise level equivalent to 0.5 nm.