CN204313802U - A kind of strain transducer based on temperature compensation fiber grating - Google Patents

Abstract

The utility model discloses a strain sensor based on a temperature-compensated optical fiber grating, which relates to the technical field of optical fiber sensors. Fiber gland B, protective cover, fiber gland A, the temperature-compensated fiber grating strain sensor is that the fiber grating is fixed in the wide groove of the fixing seat A and the fixing seat B, and the pigtails at both ends are respectively fixed in the fixing seat A and the fixing seat On B, the fixed seat A and the fixed seat B are transmitted to the fiber grating with the strain of the measured object, and the grating center wavelength changes accordingly. At the same time, the fiber grating is not affected by temperature and can truly and accurately measure the strain.

Description

A strain sensor based on temperature-compensated fiber grating

technical field

The utility model relates to the technical field of optical fiber sensors, in particular to a strain sensor based on temperature-compensated optical fiber gratings.

Background technique

Large-scale structures such as buildings, bridges, derricks and other facilities are exposed to the external environment for a long time, and are susceptible to aging or damage due to harsh environments and human influence. Strain is an important index to ensure the safety of engineering structures. People usually evaluate the health of an engineering structure by detecting the strain of the structure. Affected by external forces, the structure will produce a certain strain. If the external force is too large, it will cause cracks, strain and other damage to the structure, and further development will cause the structure to break and collapse, threatening the safety of the project. Therefore, it is of great significance to carry out long-term, real-time, dynamic and stable detection of the strain of engineering structures.

Fiber Bragg gratings are very sensitive to strain and have been widely used in the field of sensing, especially in the quasi-distribution measurement of strain, temperature, pressure ultrasonic, acceleration, magnetic field and other parameters. The measurement of strain parameters is one of several widely used applications. It is widely used in building structures such as tunnels, iron towers, tunnels, electric power, oil wells and other fields. However, the center wavelength of existing FBG strain sensors is sensitive to temperature and strain. How to eliminate the influence of temperature and improve the accuracy of strain measurement is difficult for most FBG strain sensors to overcome this problem.

Utility model content

The technical problem to be solved by the utility model is to provide a strain sensor based on temperature-compensated optical fiber gratings, which solves the above-mentioned defects in the prior art by using armored optical cables and optical fiber loose tubes.

In order to achieve the above object, the utility model provides the following technical solutions: a strain sensor based on temperature-compensated optical fiber grating, including armored optical cable, fixed seat A, optical fiber loose tube, optical fiber grating, adhesive, fixed seat B, Optical fiber gland B, protective cover, and optical fiber gland A are characterized in that: the strain sensor includes a fiber grating, and the fiber grating is fixed in the wide groove of the fixing seat A and the fixing seat B through an adhesive, and the opening on the fixing seat B is There is a rectangular chute, the fiber loose tube is sleeved on the armored cable, and the armored cable is respectively fixed on the fixing seat A and the fixing seat B through the fiber gland A, and the fiber gland A and the fixing seat A are connected and fixed by screws , The fiber gland B and the fixing seat B are connected and fixed by screws, the armored optical cables at both ends of the fiber grating are fixed in the wide grooves of the fixing seat A and the fixing seat B, and the protective cover is hard-connected to the fixing seat B through high-strength screws.

Preferably, the fiber grating is composed of a negative temperature coefficient material corresponding to the grating material and a fiber grating package.

Preferably, the fiber grating is a temperature-compensated uniform long-period fiber grating.

Preferably, the armored optical cable is a single-core single-mode indoor armored optical cable.

Preferably, the optical fiber loose tube is made of polypropylene.

The beneficial effect of adopting the above technical scheme is: the temperature-compensated fiber grating strain sensor is that the fiber grating is fixed in the wide groove of the fixing seat A and the fixing seat B, and the tail fibers at both ends are respectively fixed on the fixing seat A and the fixing seat B, so that The fixed seat A and the fixed seat B are transmitted to the fiber grating with the strain of the measured object, and the grating center wavelength changes accordingly. At the same time, the fiber grating is not affected by temperature and can truly and accurately measure the strain.

Description of drawings

Fig. 1 is a schematic diagram of explosion of a strain sensor based on temperature-compensated fiber grating of the present invention;

Fig. 2 is a structural schematic diagram of a strain sensor based on a temperature-compensated fiber grating of the present invention.

Among them, 1--armored optical cable, 2--fixing seat A, 3--optical fiber loose tube, 4--optical fiber grating, 5--adhesive, 6--fixing seat B, 7--optical fiber gland B, 8--protective cover, 9--optical fiber gland A.

Detailed ways

A preferred embodiment of a temperature-compensated fiber grating-based strain sensor of the present invention will be described in detail below in conjunction with the accompanying drawings.

Fig. 1 and Fig. 2 show the specific embodiment of a kind of strain sensor based on temperature-compensated fiber grating of the present utility model: this strain sensor based on temperature-compensated fiber grating comprises armored optical cable 1, fixed seat A2, optical fiber loose tube 3, Optical fiber grating 4, adhesive 5, holder B6, optical fiber gland B7, protective cover 8, optical fiber gland A9, it is characterized in that: described strain sensor comprises optical fiber grating 4, and optical fiber grating 4 is fixed on by adhesive 5 In the wide grooves of the fixing base A2 and the fixing base B6, there is a rectangular chute on the fixing base B6, the fiber loose tube 3 is sleeved on the armored optical cable 1, and the armored optical cable 1 is respectively fixed on the fixing base through the optical fiber gland A9 A2 and the fixing seat B6, and the fiber gland A9 and the fixing seat A2 are connected and fixed by screws, the fiber gland B7 and the fixing seat B6 are connected and fixed by screws, and the armored optical cable 1 at both ends of the fiber grating 4 is fixed on the fixing seat A2 and fixed In the wide groove of the seat B6, the protective cover 8 is hard-connected with the fixed seat B6 through high-strength screws.

The fixed seat A2 and the fixed seat B6 are in contact with each other but do not form a whole, and can move relatively axially. The connectors of the armored optical cable 1 at both ends protrude from the two ends of the sensor and can be connected with external optical fibers. The optical fiber gland A9 and the optical fiber gland The cover B7 fixes the pigtails of the fiber grating 4 on the holder. The protective cover 8 protects the strain sensor from lateral damage and influence. Put the fixing seat A2 into the chute of the fixing seat B6 so that it can slide freely, put the fiber grating 4 flatly into the wide grooves of the fixing seat A2 and the fixing seat B6, and glue on the positions at both ends of the fiber grating 4 Binder 5, after the binder 5 is cured, put the pigtails at both ends of the fiber grating 4 into the loose tube 3 and the armored optical cable 1 in sequence, and after adjusting the length of the grating, use the fiber gland A9 and the fiber gland B7 to wrap the armor The two ends of the optical cable 1 are respectively fixed on the fixing base A2 and the fixing base B6; adjust the position of the optical fiber to ensure that the optical fiber is in the correct state, then connect the protective cover 8 to the fixing base B6 with screws, and apply protective sealant; the fiber grating 4 The packaging of the strain sensor is completed, and the sensor is fixed on the measured object through the screw holes of the fixing base A2 and the fixing base B6, and the installation of the fiber grating 4 strain sensor is completed. When the measured object undergoes a corresponding strain, the corresponding strain is transmitted to the fiber grating 4 through the fixed seat A and the fixed seat B, and the strain of the measured object is reflected by the change of the center wavelength of the grating.

The above are only preferred embodiments of the present utility model, and it should be pointed out that for those of ordinary skill in the art, without departing from the inventive concept of the present utility model, some deformations and improvements can also be made, and these all belong to this utility model. Protection scope of utility model.

Claims (5)

1. the strain transducer based on temperature compensation fiber grating, comprise armored optical cable, holder A, optical fiber loose tube, fiber grating, cementing agent, holder B, optical fiber gland B, over cap, optical fiber gland A, it is characterized in that: described strain transducer comprises fiber grating, fiber grating is fixed in the sipes of holder A and holder B by cementing agent, holder B has rectangle chute, optical fiber loose tube is socketed on armored optical cable, armored optical cable is separately fixed at holder A with on holder B by optical fiber gland A, and optical fiber gland A and holder A is connected by screw fixing, optical fiber gland B and holder B is connected by screw fixing, fiber grating two ends armored optical cable is fixed on holder A with in the sipes of holder B, over cap realizes Hard link by high-strength screw and holder B.

2. the strain transducer based on temperature compensation fiber grating according to claim 1, is characterized in that: described temperature compensation fiber grating is made up of the negative temperature coefficient material corresponding with grating material and optical fiber Bragg grating encapsulation.

3. the strain transducer based on temperature compensation fiber grating according to claim 1, is characterized in that: described fiber grating is the even long period fiber grating of temperature compensation.

4. the strain transducer based on temperature compensation fiber grating according to claim 1, is characterized in that: described armored optical cable is the indoor armored optical cable of single core single mode.

5. the strain transducer based on temperature compensation fiber grating according to claim 1, is characterized in that: described optical fiber loose tube is manufactured by polypropylene.