The Development of Experimental Apparatus for Measurement of Magnetostrictive Coefficient

摘要

Design an experimental apparatus for measurement of magnetostrictive coefficient with simple operation and reasonable price. Use the characteristics of fiber grating whose central wavelength is sensitive to external strain to turn the length change of the magnetic material into the central wavelength change of the fiber grating by a mechanical device. Then turn the central wavelength change into light intensity change by the long period fiber grating, and the light intensity change will be turned into appropriate voltages for computer collection by an amplifier circuit with a pin tube. The computer will also collect the signals of external temperature (to reflect the change of the central wavelength of the fiber grating because of temperature change) and Magnetic changes of the device at the same time. Then draw a diagram of the magnetic field intensity and the length change of the magnetic material, thus, getting the magnetostrictive coefficient. The experiment shows that this experimental apparatus is feasible and practical with simple operation and low cost. It can not only overcome the shortages of the usual measuring method by non-balance electric bridge, but also be promoted to students experiments.