The Measurement System for the Giant Magnetostriction Material Based on the Laser Displacement Method

A measurement system is built to measure the magnetostrictive strain of giant magnetostriction material. The system based on the laser displacement method includes the dual laser devices, the electromagnet and the control unit. The system has the characteristics of non-contact, overall and accurate measurement. The electromagnet is used to generate the magnetic field of the maximum 5000 Oe. The magnetostrictive-strain curve of Terbium-dysprosium-iron (Terfenol-D) samples are measured. The uncertainty of magnetostrictive strain is less than 2.5% (k=2).