JPH02154126A - Sensor part for optical fiber temperature sensor - Google Patents

Abstract

PURPOSE:To facilitate the attachment of a sensor, to make a contacting area large and to improve measuring accuracy by providing a buffer layer where a sensor fiber is linearly buried on one side of a metallic tape. CONSTITUTION:The buffer layer 2 consisting of epoxyacrylate resin is linearly buried on the one side of the metallic tape 3 made of steel, etc. An adhesive layer 4 which is made of synthetic rubber system adhesive having adhesion and whose thickness is about 0.02-0.2mm is provided on the buffer layer 2 and the other side of the metallic tape 3 is covered with a sheath layer 5 consisting of the synthetic resin such as polyethylene, etc., to obtain a sensor part. With such constitution, the sensor is easily attached, and the contacting area is made large. Since a substance whose temperature should be metered approaches to the sensor fiber 1, heat transfer is excellent and the high accuracy measurement of temperature is accomplished.

Description

[Detailed Description of the Invention] "Industrial Application Field" The present invention relates to a sensor part of a distributed optical fiber temperature sensor using an optical fiber, which can be easily fixed to l:lT[lJl. be.

"Prior Art" Distributed optical fiber temperature sensors are currently being widely studied because they can detect the temperature distribution in the longitudinal direction of a sensor fiber. As the sensor part 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, so it is usually impossible to use a protective coating or a tension member on the optical fiber core wire. Or, they are used as large-diameter optical cables with an intervening device.

[Problem to be Solved by the Invention J] However, since the sensor section made of such an optical cable has a large diameter, it is not suitable for use by wrapping it around a small-diameter vibrator such as a pipe.

Furthermore, since the contact area between the optical cable and the vibrator is small, there is a delay in heat transfer, resulting in insufficient measurement accuracy. Furthermore, when attaching the optical cable to a temperature-measuring object such as a vibrator, a separate fixing device such as a fixing band is required, which poses a major practical problem in that the attachment work is troublesome.

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

``Operation'' This type of sliding sensor part can be made into a thin tape-like shape, so it is easy to install.
Moreover, the contact area also becomes larger. In addition, the adhesive layer allows for easy and quick fixing to the object to be measured.

Embodiment FIG. 1 shows an example of a sensor section of an optical fiber temperature sensor of the present invention, and reference numeral 1 in the figure is a sensor fiber. This sensor fiber 1 detects the temperature change of the object to be measured as a change in the amplitude, phase, polarization plane, etc. of the guided light.Single-mode or multi-mode quartz-based fibers are used to detect the temperature change of the object to be measured. The fibers may be bare wires, strands, or cored wires, and a plurality of fibers may be used. This sensor fiber 1 is embedded in the buffer 12 in a straight line. The buffer layer 2 is made of synthetic resin such as epoxy acrylate resin or urethane acrylate resin, and the sensor fiber 1 is embedded in a straight line in order to prevent an increase in loss due to random bending. Mechanical protection of the fiber 1 is also provided at the same time. It is desirable that the thickness of this buffer layer 2 be approximately equal to the thickness of the sensor fiber 1 buried therein.

A metal tape 3 is laminated on one surface of this buffer layer 2. This metal tape 3 is made of metal such as steel, aluminum, copper, etc., to shape the sensor part into a shape that follows the shape of the object to be measured, to facilitate the installation work, and to protect the sensor fiber 1. , its thickness is approximately 0.
A diameter of about 0.05 to 0.5 mm is used.

Furthermore, an adhesive layer 4 is provided on the other surface of the buffer layer 2. This adhesive layer 4 is for adhering and fixing the tape-shaped sensor section to the object to be measured, and various adhesives such as a sticky synthetic rubber adhesive can be used depending on the object to be measured. It will be done. The thickness of the contact layer 4 is approximately 0.02~0.2
It is said to be about mm.

Furthermore, a sheath layer 5 is provided on the metal tape 3 to cover it. This sheath layer 5 is used to prevent corrosion of the metal tape 3 and also to prevent the generation of sparks due to contact between the metal tape 3 and other metal members after the sensor section is attached to the crystal body to be measured. Therefore, as shown in FIG. 1, it has a U-shaped cross section and covers both ends of the metal tape 3, and also partially covers both ends of the buffer layer 2. This sheath layer 5 is made of a synthetic resin such as polyethylene, polypropylene, polyvinyl chloride, or fluororesin, and has a thickness of approximately 0°1 to II.

Furthermore, when actually using this sensor section, it is preferable to provide a release paper (not shown) such as silicone-treated paper on the adhesive layer 4 so that the sensor section itself can be wound.

Further, the width of the sensor section varies depending on the object to be measured, but is usually about 5n+m to 50mm.

Such a sensor part can be directly attached to the stylus using the adhesive layer 4 without using any other fixing tool, and the installation work can be facilitated. Furthermore, since the thickness can be reduced, it can be easily attached to, for example, a small-diameter vibrator. Furthermore, since the object to be measured and the sensor fiber 1 are close to each other, heat transfer is good and temperature measurement can be performed with high accuracy.

[Experimental example J: outer diameter 125 μm, core diameter 50 μm, relative refractive index difference 1.0%
A bare graded-index optical fiber was coated with silicone resin to form a wire with an outer diameter of 400 μm, which was linearly embedded in a buffer layer made of epoxy acrylate resin with a thickness of 0.4 mm. An aluminum metal tape with a thickness of 0.5 mm is pasted on one side of this buffer layer, and an adhesive layer made of chloroprene rubber adhesive with a thickness of 0.3 n+m is provided on the other side, and a metal tape is attached on the other side. A sensor portion was prepared by covering the top with a sheath layer made of polyethylene and having a thickness of 0.5 mm. The width of this sensor section was 40n+m.

When this sensor part was wrapped around a pipe having an outer diameter of 40 mm, it was possible to wrap it directly without temporarily fixing it. Furthermore, since the pitch of the winding can be defined by the width of the sensor section itself, the relationship between the length and the distance of the winding can be calculated accurately. Furthermore, the working time per 100 m of pipe was 2.5 hours, which was significantly shorter than the working time of 10 hours using the conventional sensor section.

"Effects of the Invention" As explained above, the sensor section of the optical fiber temperature sensor of the present invention includes a buffer layer in which sensor fibers are linearly embedded on one surface of a metal tape, and Since an adhesive layer is provided and the other surface of the metal tape is coated with a sheath layer, the adhesive layer can be used to easily and quickly attach the metal tape to the object to be measured. Furthermore, since the entire device is tape-shaped and its thickness can be reduced, it can be attached along any shape of the object to be measured, and its contact area can be increased.

[Brief explanation of the drawing]

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

Claims (1)

[Claims] A buffer layer in which sensor fibers are linearly embedded is provided on one surface of the metal tape, an adhesive layer is provided on this buffer layer, and a sheath layer covering this is provided on the other surface of the metal tape. A sensor section of an optical fiber temperature sensor characterized by: