JPS62250324A - Optical fiber sensor for detecting leakage - Google Patents
Optical fiber sensor for detecting leakageInfo
- Publication number
- JPS62250324A JPS62250324A JP61092224A JP9222486A JPS62250324A JP S62250324 A JPS62250324 A JP S62250324A JP 61092224 A JP61092224 A JP 61092224A JP 9222486 A JP9222486 A JP 9222486A JP S62250324 A JPS62250324 A JP S62250324A
- Authority
- JP
- Japan
- Prior art keywords
- refractive index
- leakage
- high refractive
- optical fiber
- light
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000013307 optical fiber Substances 0.000 title claims abstract description 26
- 238000001514 detection method Methods 0.000 claims abstract description 46
- 230000003287 optical effect Effects 0.000 claims abstract description 12
- 239000000835 fiber Substances 0.000 claims description 8
- 229910052710 silicon Inorganic materials 0.000 claims description 5
- 239000010703 silicon Substances 0.000 claims description 5
- 239000010409 thin film Substances 0.000 claims description 5
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims description 4
- 230000035945 sensitivity Effects 0.000 abstract description 10
- 239000007788 liquid Substances 0.000 abstract description 6
- 230000002093 peripheral effect Effects 0.000 abstract description 3
- 238000009751 slip forming Methods 0.000 abstract description 2
- 239000003921 oil Substances 0.000 description 25
- 238000005253 cladding Methods 0.000 description 7
- 239000002184 metal Substances 0.000 description 6
- 230000007423 decrease Effects 0.000 description 4
- 239000011810 insulating material Substances 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- 238000005520 cutting process Methods 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 238000009826 distribution Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000004809 Teflon Substances 0.000 description 1
- 229920006362 Teflon® Polymers 0.000 description 1
- 230000032683 aging Effects 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 150000003376 silicon Chemical class 0.000 description 1
- 229920002050 silicone resin Polymers 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M3/00—Investigating fluid-tightness of structures
- G01M3/02—Investigating fluid-tightness of structures by using fluid or vacuum
- G01M3/04—Investigating fluid-tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point
- G01M3/042—Investigating fluid-tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point by using materials which expand, contract, disintegrate, or decompose in contact with a fluid
- G01M3/045—Investigating fluid-tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point by using materials which expand, contract, disintegrate, or decompose in contact with a fluid with electrical detection means
- G01M3/047—Investigating fluid-tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point by using materials which expand, contract, disintegrate, or decompose in contact with a fluid with electrical detection means with photo-electrical detection means, e.g. using optical fibres
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
この発明は化学プラントや燃料パイプラインにおける油
や水等の漏洩を光を利用して無電源で検知できる漏洩検
知用光フアイバセンサに関するものである。[Detailed Description of the Invention] [Industrial Application Field] This invention relates to an optical fiber sensor for leak detection that can detect leaks of oil, water, etc. in chemical plants and fuel pipelines using light without a power source. be.
従来の電気的検知方法による漏洩検知センサとしては金
属線の外周をテフロン多孔質の絶縁材で被覆し、その外
側圧金属網を設け、更にその外側に多孔質の保護材を設
けたものがあった。この漏洩検知センサはその絶縁材に
油が付着して湿潤化すると、金属線と絶縁材を介在させ
た金属網間のインピーダンスが変化するため、このイン
ピーダンスの変化により油の漏洩を検知していた。しか
しながら、かかる漏洩検知センサは絶縁材に水が付着し
てもインピーダンスが変化するため、水と油との区別が
難しいことと経年変化による感度低下をもたらし、測定
できる距離も最大限１ｋｍ と短く、更に＋１電気的に
検出するために誘導ノイズや絶縁低下による誤検出や発
火原因ともなる本質的な欠陥があった。Conventional leakage detection sensors using electrical detection methods include one in which the outer periphery of a metal wire is covered with a porous Teflon insulating material, a pressure metal mesh is provided on the outside of the metal wire, and a porous protective material is provided on the outside of the metal wire. Ta. When oil adheres to the insulating material and it becomes wet, this leakage detection sensor changes the impedance between the metal wire and the metal mesh with the insulating material in between, and detects oil leakage based on this change in impedance. . However, since the impedance of such leakage detection sensors changes even when water adheres to the insulating material, it is difficult to distinguish between water and oil, the sensitivity decreases due to aging, and the measurable distance is short at 1 km. Furthermore, since the detection is carried out electrically, there is an inherent defect that can cause erroneous detection and fire due to induced noise and poor insulation.
かかる欠陥を解消せんとしたものとして光ファイバを利
用し１こ漏洩検知用光フアイバセンサが現在発明されて
いる。In an attempt to eliminate this defect, an optical fiber sensor for detecting leakage using an optical fiber has been invented.
第５図を工従来例の漏洩検知原理ファイバセンサを示す
斜視図、第６図は漏洩検知用光ファイバセンサの漏洩検
知原理を示す説明図である。FIG. 5 is a perspective view showing a conventional leakage detection principle fiber sensor, and FIG. 6 is an explanatory diagram showing the leakage detection principle of a leakage detection optical fiber sensor.
図において、（１）は光ファイバのクラッド部、（２）
はコア部で、（３）はクラッド部（１）を所定長切り欠
いてコア部（２）を露出させて形成された漏洩検知光セ
ンサ部である。In the figure, (1) is the cladding part of the optical fiber, (2)
1 is a core portion, and (3) is a leak detection optical sensor portion formed by cutting out a predetermined length of the cladding portion (1) to expose the core portion (2).
従来例の漏洩検知用光ファイバセンサは上記のように構
成され、油の漏洩検知をこの元ファイバで行う原理は、
屈折率（ｎ−１空気、ｎ −１，４〜１．５油、ｎ＝１
．３３３水）の違いを利用したもので、例えばθ１洩検
知元セ／す部（３）がコア部（２）より屈折率が大きく
なり、コア部（２）内の高次モードである伝搬モードの
光が漏洩検知光センサ部（３）で漏洩モードに変換され
る即ち外部に漏洩する＠これを光パルス試験器（ＯＴＤ
Ｒ）を用いて後方散乱光を計測すれば、漏洩の発生時刻
と発生位置を検知することができる。The conventional optical fiber sensor for detecting leakage is constructed as described above, and the principle of detecting oil leakage using this original fiber is as follows.
Refractive index (n-1 air, n-1,4~1.5 oil, n=1
．． For example, the θ1 leak detection source center part (3) has a larger refractive index than the core part (2), and the propagation mode, which is a higher order mode, in the core part (2). The light is converted to leakage mode by the leakage detection light sensor section (3), that is, it leaks to the outside.
By measuring the backscattered light using R), it is possible to detect the time and position of leakage occurrence.
上記のよった従来例の顛洩検知用光ファイバセンサで９
工、漏洩検知光センサ部（３）がクラッド部（１）を所
定長切り欠いてコア部（２）を露出させて形成された点
状センサであり、光ファイバの全長に亘る連続センサで
ないため、九油個所と＃洩検知元センサ部（３）が不一
致のときには検出不能となり、核センサ部（３）の数を
増や丁と損失が増大して後方の感度が悪くなるか或いは
検出不能となる。更に、クラッド部（１）が切り欠かれ
ていることから、機械的に弱くなると共に装作コストが
かさむという問題点があった。With the conventional optical fiber sensor for leakage detection as described above, 9
The leakage detection optical sensor part (3) is a point-like sensor formed by cutting out a predetermined length of the cladding part (1) to expose the core part (2), and is not a continuous sensor spanning the entire length of the optical fiber. If the 9 oil points and the # leak detection source sensor part (3) do not match, detection will not be possible, and if the number of nuclear sensor parts (3) is increased, the loss will increase and the rear sensitivity will deteriorate or detection will not be possible. becomes. Furthermore, since the cladding part (1) is notched, there are problems in that it becomes mechanically weak and the installation cost increases.
この発明は、かかる問題点？解決するためになされたも
ので、光ファイバの全長に亘って油等の対含漏洩油の検
知が行え、二箇所で漏液があった場合に後方の漏液を検
知感度Ｚ低下させずに検知でき、しかも安価に装作でき
ろ６４洩検知用元ファイバセンサを得ることを目的とす
る。Does this invention have such problems? This was done to solve the problem, and it is possible to detect oil and other leaked oil along the entire length of the optical fiber, and even if there is a leak in two places, it can be detected without reducing the detection sensitivity Z of the rear leak. The object of the present invention is to obtain a fiber sensor for detecting 64 leaks that can be detected and installed at low cost.
この発明に％る漏洩検知用光フアイバセンサは、中心と
なる断面が円形の第１低屈折率部な形成し、第１屈折率
部の外周に第１低屈折率部より高屈折率とした同心円筒
状の高屈折率部を形成し、高屈折率部の外周に高屈折率
部より低屈折率とした第２低屈折率部を形成し、全長に
亘る漏洩検知光センサ部を備えるように構成したもので
ある。The optical fiber sensor for leakage detection according to the present invention has a first low refractive index portion having a circular cross section at the center, and a higher refractive index than the first low refractive index portion on the outer periphery of the first refractive index portion. A concentric cylindrical high refractive index portion is formed, a second low refractive index portion having a lower refractive index than the high refractive index portion is formed on the outer periphery of the high refractive index portion, and a leak detection optical sensor portion extending over the entire length is provided. It is composed of
この発明においては、漏洩検知用元ファイバセ／すは、
中心となる＠１低屈折率部を形成し、第１低屈折率部の
外周に第１低屈折率部より高屈折率とした同心円筒状の
高屈折率部を形成し、高屈折率部の外周に高屈折率部よ
り低屈折率とした第２低屈折率部を形成し、全長に亘る
漏洩検知光センサ部を備えろようにしたから、漏液が第
２低屈折率部を通って高屈折率部のいずれかの箇所に付
着してもＩ！ｌ１ｍを検知でき、しかも同心円筒状の高
屈折率部に高次モードの光である複数の伝播モードの光
が入射されると、高屈折率部ではｉｌ及びｔｓ ９４１
！ｒ、届析廊部で反射１イヘ１１ナルｆに瓢ｌイい（か
ら、二箇所以上に油等の高屈折率の液体が付着した場合
に、後方の漏洩モードとなる伝播モードの元の反射角度
とは反射角度が異ったものとなり、漏液の検知感度が低
下することはない。In this invention, the original fiber cell for leakage detection is
A central @1 low refractive index portion is formed, and a concentric cylindrical high refractive index portion having a higher refractive index than the first low refractive index portion is formed on the outer periphery of the first low refractive index portion. A second low refractive index section having a lower refractive index than the high refractive index section is formed on the outer periphery of the second low refractive index section, and a leakage detection optical sensor section is provided along the entire length. Even if it adheres to any part of the high refractive index part, I! l1m can be detected, and when multiple propagation modes of light, which are higher-order mode lights, are incident on the concentric cylindrical high refractive index section, il and ts 941 are detected in the high refractive index section.
! r, the reflection in the analysis gallery is reflected in The reflection angle is different from the reflection angle, and the leakage detection sensitivity does not decrease.
第１図（ａ）はこの発明のＷＪ１実施例を示す一部省略
の斜視図、第１図（ｂｌはこの発明の漏洩検知用光フア
イバセンサの屈折率の分布を示す説明図、第２図はこの
発明の第１実施例を示す一部省略の断面図である。FIG. 1(a) is a partially omitted perspective view showing the WJ1 embodiment of the present invention, FIG. 1 is a partially omitted cross-sectional view showing a first embodiment of the present invention; FIG.
図において、αＩＧ工光ファイバのクラッド部に相当す
る中心となる断面が円形に形成されｒ、第１低屈折率部
、（６）は光ファイバのコア部に相当する同心円筒状の
高屈折率部で、第１屈折率部αＭの外周に第１低屈折率
部位１Ｊより高屈折率に形成されている。（至）は高屈
折率部（２）の外周に形成された第２低屈折率部で、こ
の実施例では高屈折率部（２）より低屈折率となる高屈
折率（６）の周囲の空気層が第２低屈折率部叫となる。In the figure, the central cross section corresponding to the cladding part of the αIG optical fiber is formed into a circular shape r, the first low refractive index part (6) is a concentric cylindrical high refractive index part corresponding to the core part of the optical fiber. The first low refractive index portion 1J is formed on the outer periphery of the first refractive index portion αM to have a higher refractive index than the first low refractive index portion 1J. (to) is a second low refractive index part formed on the outer periphery of the high refractive index part (2), and in this example, the area around the high refractive index (6) has a lower refractive index than the high refractive index part (2). The air layer becomes the second low refractive index section.
α４は光ファイバの全長に亘つ形成された漏洩検知光セ
ンサ部で、高屈折率部（６）で第２低屈折率部（至）で
ある空気層に露出する外周面全体が漏洩検知光センサ部
（２）となる。α4 is a leak detection optical sensor part formed over the entire length of the optical fiber, and the entire outer peripheral surface exposed to the air layer, which is the high refractive index part (6) and the second low refractive index part (toward), receives the leak detection light. This becomes the sensor section (2).
上記のように構成された漏油検知感度ファイバセンサに
おいては、元ファイバの全長に亘って漏洩検知光センサ
部α４が連続して形成されており、同心円筒状の高屈折
率部（ロ）の外周面のある箇所に高屈折率部（６）より
高い屈折率の液体、例えば漏油が付着すると、高屈折率
部υの漏油付着部分で油がないときにはある角度で反射
して伝播すべき伝播モードの元は漏洩セードに変換され
て外部に漏洩する。従って、これを光パルス試験器を用
いて後方散乱光を計測すれば、漏洩の発生時刻と発生位
置を検知することができる。また、従来例のものは、漏
洩モードに変わる高次モードの光が入りにくい構造とな
っているから、漏洩モードとなる光量が少ないのに対し
、この発明のものを；漏洩モードとなる高次モードの光
を取り込むように構成されているので、漏洩モードとな
る光量が多くなり、漏油検知感度が従来のものに比べて
向上するものとなっている。In the oil leakage detection sensitive fiber sensor configured as described above, the leakage detection optical sensor part α4 is continuously formed over the entire length of the original fiber, and the concentric cylindrical high refractive index part (b) If a liquid with a higher refractive index than the high refractive index section (6), for example leaked oil, adheres to a certain part of the outer peripheral surface, it will be reflected at a certain angle and propagate when there is no oil on the leaked oil attached section of the high refractive index section υ. The source of the power propagation mode is converted into a leakage shade and leaks to the outside. Therefore, by measuring the backscattered light using an optical pulse tester, it is possible to detect the time and position of leakage occurrence. In addition, the conventional model has a structure that makes it difficult for high-order mode light to enter the leakage mode, so the amount of light that becomes the leakage mode is small, whereas the one of the present invention; Since it is configured to take in light in the leakage mode, the amount of light in the leakage mode increases, and oil leakage detection sensitivity is improved compared to conventional ones.
次に、同心円筒状の高屈折率部（２）の外周面の二箇所
以上に油が付着した場合、高屈折率部Ｏ２内を油がな〜
゛ときにはＷ、１及び第２低屈折率部０１Ｊ。Next, if oil adheres to two or more places on the outer circumferential surface of the concentric cylindrical high refractive index section (2), the inside of the high refractive index section O2 should be kept free of oil.
゛Sometimes W, the first and second low refractive index portions 01J.
（至）に対しある角度で反射してヘリカルに伝播してき
た高次モードの光である伝播モードの光は漏洩モードに
変換されてしまうが、下流側である後方で油が付着した
箇所では、高屈折率部（２）内で、前述とは別の角度で
＠１及び第２低屈折率部α犯、ａ３で反射してヘリカル
に伝播し、前方の漏洩箇所では油が高屈折率部Ｑ２に付
着していても漏洩モードに変換されない伝播モードの光
は、後方の箇所でを：その反射角が変化していることに
より、油の付着で漏洩モードに変換されて外部に漏洩す
る。従って、二箇所以上に漏油があっても漏油の検知感
度が低下することはなく、伝送損失も大きくない。The propagation mode light, which is higher-order mode light that has been reflected at a certain angle with respect to Inside the high refractive index section (2), the oil is reflected from @1 and the second low refractive index section α at a different angle from the above, and propagates helically, and at the leak point in front, the oil leaks from the high refractive index section. The light in the propagation mode that is not converted to the leakage mode even if it adheres to Q2 is converted to the leakage mode by the attachment of oil due to the change in the reflection angle at the rear location and leaks to the outside. Therefore, even if there is oil leakage in two or more locations, the oil leakage detection sensitivity will not decrease and the transmission loss will not be large.
なお、この実施例の漏洩検知用光ファイバセンサは、通
常の光ファイバではコアが中心にあり、その外周にクラ
ッド部があるのに対し、それとは逆にコア部に相当する
高屈折率部（２）が外側に、クラッド部に相当する低屈
折率部（ｔｎが中心にあるだけなので、製作コストは通
常の光ファイバと余り変わらない。The optical fiber sensor for leakage detection of this embodiment has a core at the center and a cladding section around the outer periphery of a normal optical fiber, whereas a high refractive index section corresponding to the core section ( 2) is located on the outside and has a low refractive index portion (tn) corresponding to the cladding portion at the center, so the manufacturing cost is not much different from that of a normal optical fiber.
第３図（ａ）はこの発明の第２実施例を示す一部省略の
斜視図、第３図Φ）は、この発明の漏洩検知用光フアイ
バセンサの屈折率の分布を示す説明図である。FIG. 3(a) is a partially omitted perspective view showing a second embodiment of the present invention, and FIG. 3(Φ) is an explanatory diagram showing the refractive index distribution of the optical fiber sensor for leakage detection of the present invention. .
この実施例の第２低屈折率部ａ３は高屈折率部（２）の
外周にシリコン樹脂をコーティングして形成したシリコ
ン薄膜層である。そして、漏洩検知光センサ部り４は高
屈折率層（６）と第２低屈折率部（至）であるシリコン
薄膜層とで構成される。The second low refractive index portion a3 of this embodiment is a silicon thin film layer formed by coating the outer periphery of the high refractive index portion (2) with silicone resin. The leakage detection optical sensor section 4 is composed of a high refractive index layer (6) and a silicon thin film layer which is a second low refractive index section.
このシリコン薄膜層は漏油が付着すると、油がシリコン
薄膜層に浸漬し、油付着部分は屈折率がｎ＝−１，４０
５の低屈折率からｎ−１，４５１の高屈折率に変化する
。そうすると、高屈折率部（２）内の伝播モードの光は
漏洩モードに変換されて外部に漏洩される。従ってこれ
な元パルス試験器を用いて後方散乱光を計測すれば、漏
洩の発生時刻と発生位置を検知することができる。When leaked oil adheres to this silicon thin film layer, the oil immerses into the silicon thin film layer, and the refractive index of the oil-attached area is n=-1,40.
The refractive index changes from a low refractive index of 5 to a high refractive index of n-1,451. Then, the light in the propagation mode within the high refractive index portion (2) is converted into a leakage mode and leaked to the outside. Therefore, by measuring the backscattered light using this original pulse tester, it is possible to detect the time and position of leakage occurrence.
上記第１実施例、第２実施例ではいずれも第１低屈折率
部αυと高屈折率部ａ３の屈折率は第１図（ａ）。In both the first and second embodiments, the refractive indexes of the first low refractive index portion αυ and the high refractive index portion a3 are as shown in FIG. 1(a).
第３回向に示すように真中と内側と外側を工いずれも均
一であるが、第４図に示すように第１低屈折率部αｖ＆
工その屈折率を真中から内側と外側にいくに従い次第に
増加するように形成し、高屈折率部（２）はその屈折率
を真中から内側と外側にいくに従い次第に減少するよう
にしてもよいことは勿論である。As shown in the third direction, the middle, inner and outer parts are uniformly machined, but as shown in Fig. 4, the first low refractive index part αv&
The refractive index of the high refractive index portion (2) may be formed so that it gradually increases from the center toward the inside and outside, and the refractive index of the high refractive index portion (2) may gradually decrease from the center toward the inside and outside. Of course.
この発明は以上説明したとおり、中心となる第１低屈折
率部を形成し、第１低屈折率部の外周に第１低屈折率部
より高屈折率としたーｊ心円筒状の高屈折率部を形成し
、高屈折率部の外周に高屈折率部より低屈折率とした第
２低屈折率部を形成し、全長に亘る滉洩検知光センサ部
を備えるようにしたので、漏油等の液体が第２低屈折率
部を通して高屈折率部の外周面におげろ婦洩検知光七“
ンサ部のいずれの箇所に付着しても感度よく検知でき、
格別の加工を必要としない従来の元ファイバの１作と同
様であるから製作コストも安くて済み、しかも高屈折率
部に高次モードの光である）Ｗ数の伝播モードの光が入
射されろと、高屈折率部では第１及び第２低屈折率部で
反射してヘリカルに伝播していくから、＝１，８所以上
に油等の高屈折率の液体が付着した場合にも、前方の漏
洩モードとなる伝播モードの光とは反射角度の異ったヘ
リカルに伝播していく伝播モードの光が後方で漏洩モー
ドとなり、後方の漏洩の検知感度を低下させることなく
漏液を検知できろという効果がある。As explained above, this invention forms a central first low refractive index part, and has a cylindrical high refractive index on the outer periphery of the first low refractive index part, which has a higher refractive index than the first low refractive index part. A second low refractive index portion is formed on the outer periphery of the high refractive index portion, and a second low refractive index portion is formed with a lower refractive index than the high refractive index portion, and a leakage detection optical sensor portion is provided over the entire length. If a liquid such as oil passes through the second low refractive index section and onto the outer circumferential surface of the high refractive index section, the leakage detection light is emitted.
It can be detected with high sensitivity no matter where it adheres to the sensor part.
Since it is similar to a conventional original fiber that does not require any special processing, the manufacturing cost is low, and the high-order mode light (W) propagation mode light is incident on the high refractive index section. In the high refractive index part, it is reflected by the first and second low refractive index parts and propagates in a helical manner, so even if a high refractive index liquid such as oil adheres to more than 1.8 places. , the light in the propagation mode that propagates in a helical manner with a different reflection angle from the light in the propagation mode that becomes the leakage mode in the front becomes the leakage mode in the rear, and it is possible to detect liquid leakage without reducing the detection sensitivity of leakage in the rear. It has the effect of being detectable.
第１図（ａｌｔ！この発明の第１実施例を示す一部省略
の斜視図、第１図（ｂｌ ｔヱこの発明の漏洩検知用光
ファイバセンサの屈折率の分布を示す説明図、第２図は
この発明の第１実施例を示す一部省略の断面図、第６図
はこの発明の第２実施例を示す一部省略の斜視図、第４
図はこの発明の漏洩検知用光フアイバセンサの別の屈折
率の分布を示す図、第５図は従来の漏洩検知州党ファイ
バセンサを示す斜視図、第６図は漏洩検知用光フアイバ
センサの漏洩検知原理を示す説明図である。
図において、αυは第１低屈折率部、ａｚは高１１（折
率部、０３は第２低屈折率部、ａＯは８洩検知光センサ
部である。
代理人 弁理士 佐 藤 正 年
第１図
（ｂ） （ａ）第３図
（ｂ） （Ｑ）
第５図
第６図FIG. 1 (alt! A partially omitted perspective view showing the first embodiment of the present invention, FIG. 6 is a partially omitted sectional view showing a first embodiment of the invention, FIG. 6 is a partially omitted perspective view showing a second embodiment of the invention, and FIG.
Figure 5 shows another refractive index distribution of the optical fiber sensor for leak detection of the present invention, Figure 5 is a perspective view of a conventional optical fiber sensor for leak detection, and Figure 6 shows the optical fiber sensor for leak detection. It is an explanatory diagram showing a leakage detection principle. In the figure, αυ is the first low refractive index part, az is the high 11 (high refractive index part), 03 is the second low refractive index part, and aO is the 8 leakage detection optical sensor part. Agent: Masaru Sato, Patent Attorney Figure 1 (b) (a) Figure 3 (b) (Q) Figure 5 Figure 6
Claims (3)
、第１低屈折率部の外周に第１低屈折率部より高屈折率
とした同心円筒状の高屈折率部を形成し、高屈折率部の
外周に高屈折率部より低屈折率とした第２低屈折率部を
形成し、全長に亘る漏洩検知光センサ部を備えるように
したことを特徴とする漏洩検知用光ファイバセンサ。(1) A first low refractive index part is formed with a circular cross section at the center, and a concentric cylindrical high refractive index part with a higher refractive index than the first low refractive index part is formed on the outer periphery of the first low refractive index part. A second low refractive index portion having a lower refractive index than the high refractive index portion is formed on the outer periphery of the high refractive index portion, and a leak detection optical sensor portion extending over the entire length is provided. Optical fiber sensor for use.
ることを特徴とする特許請求の範囲第１項記載の漏洩検
知用ファイバセンサ。(2) The fiber sensor for leakage detection according to claim 1, wherein the second low refractive index portion is an air layer surrounding the high refractive index portion.
グされたシリコン薄膜層であることを特徴とする特許請
求の範囲第１項記載の漏洩検知用光ファイバセンサ。(3) The optical fiber sensor for leakage detection according to claim 1, wherein the second low refractive index portion is a silicon thin film layer coated on the outer periphery of the high refractive index portion.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61092224A JPS62250324A (en) | 1986-04-23 | 1986-04-23 | Optical fiber sensor for detecting leakage |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61092224A JPS62250324A (en) | 1986-04-23 | 1986-04-23 | Optical fiber sensor for detecting leakage |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS62250324A true JPS62250324A (en) | 1987-10-31 |
Family
ID=14048467
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61092224A Pending JPS62250324A (en) | 1986-04-23 | 1986-04-23 | Optical fiber sensor for detecting leakage |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS62250324A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2006132395A1 (en) * | 2005-06-08 | 2006-12-14 | Fujifilm Corporation | Plastic optical medium and production method thereof |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5017850A (en) * | 1973-06-15 | 1975-02-25 | ||
| JPS5256548A (en) * | 1975-11-05 | 1977-05-10 | Sumitomo Electric Ind Ltd | Fiber for optical transmission |
| JPS52151577A (en) * | 1976-06-11 | 1977-12-16 | Omron Tateisi Electronics Co | Optical amplifier |
| JPS5389793A (en) * | 1977-01-19 | 1978-08-07 | Toshiba Corp | Leakage detector |
| JPS5983106A (en) * | 1982-11-04 | 1984-05-14 | Furukawa Electric Co Ltd:The | Optical fiber for detecting liquid leakage |
| JPS60225297A (en) * | 1984-04-23 | 1985-11-09 | 日本電気株式会社 | Optical fiber monitor |
-
1986
- 1986-04-23 JP JP61092224A patent/JPS62250324A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5017850A (en) * | 1973-06-15 | 1975-02-25 | ||
| JPS5256548A (en) * | 1975-11-05 | 1977-05-10 | Sumitomo Electric Ind Ltd | Fiber for optical transmission |
| JPS52151577A (en) * | 1976-06-11 | 1977-12-16 | Omron Tateisi Electronics Co | Optical amplifier |
| JPS5389793A (en) * | 1977-01-19 | 1978-08-07 | Toshiba Corp | Leakage detector |
| JPS5983106A (en) * | 1982-11-04 | 1984-05-14 | Furukawa Electric Co Ltd:The | Optical fiber for detecting liquid leakage |
| JPS60225297A (en) * | 1984-04-23 | 1985-11-09 | 日本電気株式会社 | Optical fiber monitor |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2006132395A1 (en) * | 2005-06-08 | 2006-12-14 | Fujifilm Corporation | Plastic optical medium and production method thereof |
| JP2006343455A (en) * | 2005-06-08 | 2006-12-21 | Fujifilm Holdings Corp | Manufacturing method of plastic optical material |
| US7813610B2 (en) | 2005-06-08 | 2010-10-12 | Fujifilm Corporation | Plastic optical medium and production method thereof |
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