Bimetal sheet type optical fiber microbending temperature sensor

Abstract

The invention provides a bimetallic strip type microbend optical fiber temperature sensor, which comprises a microbend optical fiber deforming device, a signal optical fiber imbedded in the microbend optical fiber deforming device and a bimetallic strip, wherein the bimetallic strip contacts with the microbend optical fiber deforming device. The bimetallic strip in the inventive bimetallic strip type microbend optical fiber temperature sensor can generate displacement according to the temperature variation, so as to generate deflection variation which acts on the microbend optical fiber deforming device to make the deforming device generate displacement, so as to change the bending loss of optical fiber. In this way, the temperature signal is converted to optical signal, which can be transmitted by the optical fiber to realize long-distance measurement with high precision and good reliability.

Description

technical field [0001] The invention relates to a temperature sensor, in particular to a bimetallic sheet-type optical fiber microbending sensor which utilizes the temperature characteristics of bimetallic sheets and optical fiber microbending loss. Background technique [0002] Traditional temperature measurement sensors, such as thermistors and thermocouples, will be greatly affected by strong electric fields and strong magnetic fields. At the same time, it is not suitable for long-distance measurement, which will bring great deviation, which is not conducive to the use in explosion-proof occasions. . The fiber optic temperature sensor has many advantages and has attracted people's attention. For example, fiber Bragg grating temperature sensor has been researched a lot, but the demodulation cost of fiber Bragg grating is high, and its application is limited. [0003] The optical fiber microbend sensor was first proposed by J.N.Fields and J.H.Cole in 1980, and it belongs ...

AI Technical Summary

Problems solved by technology

Because two sets of lenses are used to focus the output light of the optical fiber on the grating disk to form two light spots, the disadvantages are large volume, difficult debugging and poor stability.

[0008] Chinese patent application 200310111511.2 discloses a "microbent optical fiber temperature sensor". When the temperature changes, the geometric size of the temperature sensor will push the optical fiber microbending deformer to move due to thermal expansion and contraction. Change the bending degree of the signal fiber to realize the modulation of the light intensity in the signal fiber. The disadvantages are low sensitivity and large volume.

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