JP2545127B2 - Sensor part of optical fiber temperature sensor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Industrial field of application" The present invention relates to a sensor portion of a distributed optical fiber temperature sensor using an optical fiber, which is easily fixed to a temperature-measuring object. is there.

"Prior Art" Distributed optical fiber temperature sensors are currently being widely studied because they can detect the temperature distribution in the longitudinal direction of the sensor fiber. As a sensor portion of such an optical fiber temperature sensor, it is impossible to use a small-diameter optical fiber as it is from the viewpoint of mechanical strength and the like, and normally, a protective coating, a tension member or an interposition is provided on the optical fiber core wire. It is used as a large-diameter optical cable by providing such as.

[Problems to be Solved by the Invention] However, since the sensor portion including such an optical cable has a large diameter, it is not suitable to be used by being wound around a pipe having a small diameter such as a pipe. In addition, since the contact area between the optical cable and the pipe is small, heat transfer is delayed, which results in insufficient measurement accuracy. Further, when attaching the optical cable to a temperature-measured body such as a pipe, a fixing tool such as a fixing band is separately required, which is a big problem in practical use that the attaching work is troublesome.

"Means for Solving the Problems" In the present invention, a buffer layer in which a sensor fiber is linearly embedded is provided on one surface of a metal tape, an adhesive layer is provided on the buffer layer, and the other of the metal tape is provided. The above problem is solved by using the surface of which is covered with a sheath layer as a sensor portion.

"Operation" In the sensor portion having such a structure, the whole shape can be formed into a thin tape shape, so that the attachment is easy and the contact area is large. Further, the adhesive layer makes it possible to easily and quickly fix the temperature measurement target.

"Embodiment" FIG. 1 shows an example of a sensor portion of an optical fiber temperature sensor according to the present invention. In the figure, reference numeral 1 is a sensor fiber. The sensor fiber 1 detects a temperature change of the temperature-measuring object as a change in the amplitude of the guided light, a change in the phase, a change in the polarization plane, etc. A single-mode type or a multi-mode type silica optical fiber is used. Bare fiber, bare wire,
Any of the core wires may be used, and a plurality of fibers may be used. The sensor fiber 1 is linearly embedded in the buffer layer 2. The buffer layer 2 is made of a synthetic resin such as an epoxy acrylate resin or a urethane acrylate resin, and the sensor fiber 1 is embedded in the inside thereof in a linear shape in order to prevent an increase in loss due to random bending. The mechanical protection of the fiber 1 is also performed at the same time. This buffer layer 2
It is desirable that the thickness of the sensor is approximately equal to the thickness of the sensor fiber 1 embedded therein.

A metal tape 3 is laminated on one surface of the buffer layer 2. This metal tape 3 forms the sensor part in a shape that conforms to the shape of the temperature-measuring object, facilitates the mounting work, and protects the sensor fiber 1.
It is made of metal such as aluminum and copper, and its thickness is about 0.
Something from 05 to 0.5 mm is used.

An adhesive layer 4 is provided on the other surface of the buffer layer 2. The adhesive layer 4 is for adhering and fixing the tape-shaped sensor portion to the temperature-measured body, and various adhesives such as an adhesive synthetic rubber adhesive are used depending on the temperature-measured body. To be The thickness of the adhesive layer 4 is about 0.02 to 0.2 mm.

Further, a sheath layer 5 that covers the metal tape 3 is provided on the metal tape 3. This sheath layer 5 is a metal tape 3
Is to prevent the corrosion of the sensor and the generation of sparks due to the contact between the metal tape 3 and another metal member after the sensor unit is attached to the temperature-measuring body. As shown in FIG. The U-shaped cross section covers both end portions of the metal tape 3, and further covers a part of both end portions of the buffer layer 2. The sheath layer 5 is made of synthetic resin such as polyethylene, polypropylene, polyvinyl chloride, fluororesin, and has a thickness of about 0.1 to 1 mm.

Furthermore, when actually using this sensor unit, a release paper (not shown) such as silicone-treated paper is provided on the adhesive layer 4.
Is preferably provided so that the sensor unit itself can be wound.

In addition, the width of the sensor portion varies depending on the temperature-measuring object to be measured, but is usually about 5 mm to 50 mm.

Such a sensor unit can be attached to the temperature-measuring body using the adhesive layer 4 directly without using any other fixture, and the mounting work can be facilitated. Further, since the thickness can be reduced, it can be easily attached to, for example, a thin pipe. Furthermore, since the temperature-measured body and the sensor fiber 1 are close to each other, heat transfer is good and highly accurate temperature measurement can be performed.

[Experimental Example] A bare fiber of graded index type optical fiber with an outer diameter of 125 μm, a core diameter of 50 μm and a relative refractive index difference of 1.0% is coated with silicone resin to form a bare wire with an outer diameter of 400 μm. It was embedded linearly in a 0.4 mm thick buffer layer. The thickness of one side of this buffer layer is 0.
A 5 mm aluminum metal tape is attached, a 0.3 mm thick chloroprene rubber adhesive layer is provided on the other surface, and a 0.5 mm thick sheath layer made of polyethylene is coated on the metal tape. The sensor part was created. The width of this sensor part was 40 mm.

When this sensor part was wrapped around a pipe with an outer diameter of 40 mm,
It could be wound directly without temporary fixing.
Further, since the winding pitch can be defined by the width of the sensor unit itself, the relationship between the winding length and the distance can be calculated accurately.
Furthermore, the working time per 100 m of piping was 2.5 hours, which was significantly shorter than the conventional working time of 10 hours using the sensor unit.

"Effects of the Invention" As described above, the sensor portion of the optical fiber temperature sensor of the present invention has a buffer layer in which the sensor fiber is linearly embedded in one surface of the metal tape, and the sensor layer is provided on the buffer layer. Since the adhesive layer is provided and the sheath layer is coated on the other surface of the metal tape, by using the adhesive layer, the attachment to the temperature-measuring body can be performed easily and quickly. Further, since the whole is tape-like and the thickness thereof can be made thin, it can be attached to any temperature-measured object along with it, and the contact area can be increased.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing an example of a sensor portion of the optical fiber temperature sensor of the present invention. 1 ... Sensor fiber, 2 ... Buffer layer, 3 ... Metal tape, 4 ... Adhesive layer, 5 ... Sheath layer.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Tatsuya Tozaki, Inventor Tatsuya Tozaki, No. 20 Kitakanzan, Otaka-machi, Midori-ku, Nagoya, Aichi Chubu Electric Power Co., Inc. Power Technology Research Center (72) Inventor Takao Shioda, Sakura City, Chiba Prefecture 1440 Rokuzaki Fujikura Electric Cable Co., Ltd.Sakura Factory (72) Inventor Fumio Wada 1440 Rokuzaki, Sakura City, Chiba Fujikura Electric Co., Ltd.Sakura Factory

Claims (1)

(57) [Claims] 1. A buffer layer in which a sensor fiber is linearly embedded is provided on one surface of a metal tape, an adhesive layer is provided on the buffer layer, and the other surface of the metal tape is covered with the adhesive layer. A sensor unit of an optical fiber temperature sensor, which is provided with a sheath layer for controlling the temperature.