A grating fiber optic magnetic field sensor with temperature compensation and its preparation method and distributed measurement system based on it

Abstract

The invention discloses an optical grating fiber magnetic field sensor with temperature compensation, and a preparation method and a distributed measurement system based on the sensor, and belongs tothe technical field of the optical fiber sensor. The optical grating fiber magnetic field sensor comprises a magnetic field measurement optical grating, a temperature compensation optical grating, magnetostrictive Terfenol-D particles and an epoxy resin matrix. The magnetostrictive Terfenol-D particles present a certain orientation distribution in the epoxy resin matrix, so that the deformation epsilon of the magnetostrictive material along a magnetic field direction is more concentrated, the strain transmission loss is smaller by adopting a metallized nickel layer, and the particle shape caneffectively reduce the production of abnormal heat of the magnetostrictive material caused by the magnetic hysteresis loss and eddy current loss, thereby entirely improving the sensitivity of the sensor. The sensor disclosed by the invention effectively solves a temperature compensation problem, and the sensitivity of the sensor is improved; a connection problem of the optical fiber and the epoxyrein is solved at the same time; the stability and the service life of the sensor are improved, the volume is small, and the high-precision measurement can be easily accomplished in small space.

Description

technical field [0001] The invention belongs to the technical field of optical fiber sensors, and relates to a grating optical fiber magnetic field sensor with temperature compensation, a preparation method and a distributed measurement system based thereon. Background technique [0002] With the rapid development of urbanization and industry in our country, people's quality of life and level are constantly improving, and people are more pursuing a healthy working and living environment. Therefore, in recent years, more and more attention has been paid to the measurement and protection of weak electromagnetic fields. Key words such as electromagnetic pollution It also appears in the public eye, and people who work for a long time or live near high-voltage transmission lines and high-voltage substations are deeply affected. A large number of research data have shown that weak power frequency electromagnetic fields have adverse effects on human health and mental psychology. Th...

AI Technical Summary

Problems solved by technology

The device has the feature of real-time monitoring of the spatial magnetic field intensity vector through the magnetostrictive material in three directions and the fiber grating fixed on it, but this feature makes the sensor volume larger, and although the sensor uses Terfenol-D material, A large magnetostriction coefficient has been obtained, but the hysteresis loss and eddy current loss of Terfenol-D are very large in dynamic state, and the temperature rise is serious, which leads to excessive thermal deformation and affects the sensitivity of the sensor, especially the sensor needs to be controlled by external factors such as ambient temperature Working under the influence of constant changes, without being able to rule out the influence of temperature, will make the sensitivity of the measurement data lack

At the same time, as a real-time monitoring magnetic field sensor, the fixing method of the fiber grating also directly affects the accuracy and service life of the sensor, and the sensor uses a traditional fiber Bragg grating, and its sensitivity is relatively low

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