JPH02156135A - Liquid detection sensor for optical fiber - Google Patents
Liquid detection sensor for optical fiberInfo
- Publication number
- JPH02156135A JPH02156135A JP31072488A JP31072488A JPH02156135A JP H02156135 A JPH02156135 A JP H02156135A JP 31072488 A JP31072488 A JP 31072488A JP 31072488 A JP31072488 A JP 31072488A JP H02156135 A JPH02156135 A JP H02156135A
- Authority
- JP
- Japan
- Prior art keywords
- liquid
- optical fiber
- sectional area
- detection sensor
- movable part
- 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
- 239000007788 liquid Substances 0.000 title claims abstract description 56
- 239000013307 optical fiber Substances 0.000 title claims abstract description 40
- 238000001514 detection method Methods 0.000 title claims abstract description 26
- 239000000463 material Substances 0.000 claims abstract description 43
- 230000008961 swelling Effects 0.000 claims description 15
- 230000035945 sensitivity Effects 0.000 abstract description 8
- 238000005452 bending Methods 0.000 abstract description 3
- 230000005540 biological transmission Effects 0.000 abstract description 2
- 239000012466 permeate Substances 0.000 abstract description 2
- 229920002725 thermoplastic elastomer Polymers 0.000 description 8
- 238000000034 method Methods 0.000 description 5
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 5
- 239000000835 fiber Substances 0.000 description 4
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 3
- 238000007654 immersion Methods 0.000 description 3
- 238000003780 insertion Methods 0.000 description 3
- 230000037431 insertion Effects 0.000 description 3
- 239000004677 Nylon Substances 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
- 238000000576 coating method Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000003365 glass fiber Substances 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 229920001778 nylon Polymers 0.000 description 2
- -1 polyethylene Polymers 0.000 description 2
- 239000004814 polyurethane Substances 0.000 description 2
- 229920005989 resin Polymers 0.000 description 2
- 239000011347 resin Substances 0.000 description 2
- 229920001187 thermosetting polymer Polymers 0.000 description 2
- LLVWLCAZSOLOTF-UHFFFAOYSA-N 1-methyl-4-[1,4,4-tris(4-methylphenyl)buta-1,3-dienyl]benzene Chemical compound C1=CC(C)=CC=C1C(C=1C=CC(C)=CC=1)=CC=C(C=1C=CC(C)=CC=1)C1=CC=C(C)C=C1 LLVWLCAZSOLOTF-UHFFFAOYSA-N 0.000 description 1
- 229920002134 Carboxymethyl cellulose Polymers 0.000 description 1
- JOYRKODLDBILNP-UHFFFAOYSA-N Ethyl urethane Chemical compound CCOC(N)=O JOYRKODLDBILNP-UHFFFAOYSA-N 0.000 description 1
- 229920003171 Poly (ethylene oxide) Polymers 0.000 description 1
- 239000004698 Polyethylene Substances 0.000 description 1
- 239000004372 Polyvinyl alcohol Substances 0.000 description 1
- 229920002125 Sokalan® Polymers 0.000 description 1
- 229920002472 Starch Polymers 0.000 description 1
- 229920006465 Styrenic thermoplastic elastomer Polymers 0.000 description 1
- BZHJMEDXRYGGRV-UHFFFAOYSA-N Vinyl chloride Chemical compound ClC=C BZHJMEDXRYGGRV-UHFFFAOYSA-N 0.000 description 1
- 239000011358 absorbing material Substances 0.000 description 1
- 150000001336 alkenes Chemical class 0.000 description 1
- 150000001408 amides Chemical class 0.000 description 1
- 229920001577 copolymer Polymers 0.000 description 1
- 229920003244 diene elastomer Polymers 0.000 description 1
- 150000001993 dienes Chemical class 0.000 description 1
- 229920001971 elastomer Polymers 0.000 description 1
- 150000002148 esters Chemical class 0.000 description 1
- 229920000578 graft copolymer Polymers 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 239000000178 monomer Substances 0.000 description 1
- JRZJOMJEPLMPRA-UHFFFAOYSA-N olefin Natural products CCCCCCCC=C JRZJOMJEPLMPRA-UHFFFAOYSA-N 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 229920003023 plastic Polymers 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 229920000058 polyacrylate Polymers 0.000 description 1
- 239000004584 polyacrylic acid Substances 0.000 description 1
- 229920001225 polyester resin Polymers 0.000 description 1
- 239000004645 polyester resin Substances 0.000 description 1
- 229920000573 polyethylene Polymers 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 229920001296 polysiloxane Polymers 0.000 description 1
- 229920002635 polyurethane Polymers 0.000 description 1
- 229920003225 polyurethane elastomer Polymers 0.000 description 1
- 229920002451 polyvinyl alcohol Polymers 0.000 description 1
- 229920000915 polyvinyl chloride Polymers 0.000 description 1
- 239000004800 polyvinyl chloride Substances 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 239000008107 starch Substances 0.000 description 1
- 235000019698 starch Nutrition 0.000 description 1
- 229920005992 thermoplastic resin Polymers 0.000 description 1
Abstract
Description
【発明の詳細な説明】
「産業上の利用分野」
本発明は、漏水や漏油等の検知精度を向上させｆこ光フ
ァイバ液体検知センサに関するものである。DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to an optical fiber liquid detection sensor that improves the accuracy of detecting water leakage, oil leakage, etc.
「従来の技術」
光ファイバ液体検知センサとしては、特願昭６２−６２
２５８にて提案された光ファイバ浸水検知センサ等があ
る。以下、従来の光ファイバ液体検知センサについて第
３図を用いて説明する。``Prior art'' As an optical fiber liquid detection sensor, a patent application filed in 1986-62
There is an optical fiber water immersion detection sensor proposed in No. 258. Hereinafter, a conventional optical fiber liquid detection sensor will be explained using FIG. 3.
図中符号■は光ファイバを示し、この光ファイバ１は、
容器２に設けられた挿通孔３．３から容器２内に挿通さ
れている。この中空角柱状の容器２内部の下部側には液
体膨潤性材料４が収納されており、その上端部には、先
端を上方に向けた状態のくさび形凸部５を有する可動部
６が載置されている。また容器２内部上端面には、上記
くさび形凸部５と嵌合するくさび形四部７が設けられて
いる。上記光ファイバ！は、この容器上端面とくさび形
凸部５の先端との間に挿通されている。The symbol ■ in the figure indicates an optical fiber, and this optical fiber 1 is
It is inserted into the container 2 through an insertion hole 3.3 provided in the container 2. A liquid-swellable material 4 is stored in the lower part of the hollow prismatic container 2, and a movable part 6 having a wedge-shaped convex part 5 with the tip facing upward is mounted on the upper end thereof. It is placed. Further, on the upper end surface inside the container 2, there are provided four wedge-shaped portions 7 that fit into the wedge-shaped convex portions 5. The above optical fiber! is inserted between the upper end surface of the container and the tip of the wedge-shaped protrusion 5.
容器２は液体が内部に容易に侵入しうる材料らしくは構
造となっており、また液体膨潤性材料・１は液体により
膨潤し体積が増大する材料か用いられている。The container 2 is constructed of a material that allows liquid to easily penetrate into the container, and the liquid-swellable material 1 is made of a material that swells with liquid and increases in volume.
次にこの光ファイバ液体検知センサの検知機構について
説明する。Next, the detection mechanism of this optical fiber liquid detection sensor will be explained.
まず液体が侵入した場合、その液体は容器２内に浸透し
、液体膨潤性材料４を膨潤させる。次に膨潤した液体膨
潤性材料４は体積が増加し可動部６を上方に移動させろ
。この時、可動部６に設けられたくさび形凸部５は光フ
ァイバＩを押しあげる。これにより光ファイバ１には曲
がりが生じ、この曲がり部分での伝送損失を感知するこ
とにより液体の侵入を検知する。First, when a liquid enters, the liquid penetrates into the container 2 and causes the liquid-swellable material 4 to swell. Next, the swollen liquid-swellable material 4 increases in volume and moves the movable part 6 upward. At this time, the wedge-shaped convex portion 5 provided on the movable portion 6 pushes up the optical fiber I. This causes a bend in the optical fiber 1, and intrusion of liquid is detected by sensing transmission loss at this bend.
「発明が解決しようとする課題」
ところが、このように膨潤による体積増加により液体の
侵入を検知する機構のため、侵入した液体が少量の場合
は体積増加量が少なく、よって可動部６の移動量が少な
くなり、液体侵入を検知できない問題すなわち感度が悪
い問題が生じる。``Problem to be Solved by the Invention'' However, since the mechanism detects the intrusion of liquid by the increase in volume due to swelling, if the amount of intruding liquid is small, the amount of increase in volume is small, and therefore the amount of movement of the movable part 6 is This results in a problem of not being able to detect liquid intrusion, that is, a problem of poor sensitivity.
ここで液体膨潤性材料４のもとの体積をＶ、可動部の移
動方向に垂直な面の断面積をＡ、肉厚をｈとし、さらに
膨潤後の体積増加量をΔＶ１その膨潤率をαとし、可動
部６の移動ＭをΔｈとしたとき、
ΔＶ＝ＡΔｈ１ ｖ−Ａｈｌ α−ΔＶ／Ｖである
ことより、
Δｈ−αｈ （１）
となる
少量の液体にて可動部６の移動量Δｈを大きくする方法
、すなわち上記問題点である検知の感度を上げる方法と
しては、（１）式より、膨潤率αを大きくずろ方法、お
よび液体膨潤性材料４の肉厚りを大きくする方法の２つ
の方法が考えられる。Here, the original volume of the liquid-swellable material 4 is V, the cross-sectional area of the plane perpendicular to the moving direction of the movable part is A, the wall thickness is h, and the volume increase after swelling is ΔV1, and the swelling rate is α When the movement M of the movable part 6 is Δh, since ΔV=AΔh1 v−Ahl α−ΔV/V, the amount of movement Δh of the movable part 6 with a small amount of liquid becomes Δh−αh (1) From equation (1), there are two methods to increase the detection sensitivity, namely, to increase the swelling ratio α and to increase the thickness of the liquid-swellable material 4. There are two possible methods.
しかし、膨潤率αを大きくするためには、■材料の選択
、■体積Ｖの減少の２つの方法が予想されろが、このう
ち■に関しては最適なものを選択すればよく、■に関し
ては体積が少ないと膨潤時に可動部６を押しあげる圧力
が不足してしまう問題がある。However, in order to increase the swelling ratio α, there are two possible methods: (1) selection of materials, and (2) reduction in volume V. Of these, it is sufficient to select the optimal method for (2), and for (2) volume V. If the amount is too small, there is a problem in that there is insufficient pressure to push up the movable part 6 during swelling.
また、もう１つの方法である肉厚りの値を大きくする方
法をとると、光ファイバ液体検知センサの形状が大きく
なってしまい、設置場所が限られるという問題が生じて
しまう。Moreover, if the other method of increasing the wall thickness value is adopted, the shape of the optical fiber liquid detection sensor becomes large, resulting in a problem that the installation location is limited.
本発明は、上記事情に鑑みなされたしので、形状を小さ
く保ち、かつ感度の良好な光ファイバ液体検知センサを
提供することを目的とする。The present invention was made in view of the above circumstances, and an object of the present invention is to provide an optical fiber liquid detection sensor that can be kept small in size and has good sensitivity.
「課題を解決するたぬの手段」
本発明の光ファイバ液体検知センサは、可動部の移動方
向に垂直な面の可動部の断面積をＡ、、可動部の移動方
向に垂直な面の液体膨潤性材料の断面積をＡｔとしたと
き、Ａ、＜Ａｔとすることを、解決するための手段とし
た。"An inconvenient means to solve the problem" The optical fiber liquid detection sensor of the present invention has a cross-sectional area of the movable part in a plane perpendicular to the direction of movement of the movable part as A, and a liquid in the plane perpendicular to the direction of movement of the movable part. The solution was to set A<At, where At is the cross-sectional area of the swellable material.
「作用 」
可動部の断面積を、液体膨潤性材料の断面積より小さく
することにより、少量の液体が侵入した場合でら膨潤性
材料の膨潤に伴う体積増加による可動部の移動量を多く
することかでき、先ファイバに曲げを生じさせることが
できる。これにより、少量の液体の浸入を検知すること
ができる。"Function" By making the cross-sectional area of the movable part smaller than the cross-sectional area of the liquid-swellable material, the amount of movement of the movable part due to the increase in volume due to swelling of the swellable material is increased even when a small amount of liquid enters. It is possible to bend the tip fiber. Thereby, intrusion of a small amount of liquid can be detected.
以下、本発明について第１図および第２図に示す実施例
を用いて説明する。The present invention will be explained below using embodiments shown in FIGS. 1 and 2.
図中符号８は、液体膨潤性材料収納部（以下、収納部と
する）を示す。この中空角柱状の収納部８の内部には、
液体膨潤性材料４が収納されている。また、その上面に
は中空角柱状の凸部９が設けられており、この凸部９の
内部空間は、その下面にて収納部８の内部空間と連通さ
れている。この凸部９には、光ファイバｌを挿通するた
めの挿通孔１Ｏ１１０が設けられており、光ファイバ１
はこれら挿通孔１０．１０から上記凸部９内に挿通され
ている。上記液体膨潤性材料４の上端面には、先端を上
方に向けた状聾のくさび形凸部１１を有する可動部１２
が凸部９内に載置されている。Reference numeral 8 in the figure indicates a liquid-swellable material storage section (hereinafter referred to as storage section). Inside this hollow prismatic storage section 8,
A liquid swellable material 4 is housed therein. Further, a hollow prismatic convex portion 9 is provided on its upper surface, and the internal space of this convex portion 9 is communicated with the internal space of the storage portion 8 at its lower surface. This convex portion 9 is provided with an insertion hole 1O110 through which the optical fiber 1 is inserted.
are inserted into the convex portion 9 from these insertion holes 10.10. On the upper end surface of the liquid-swellable material 4, there is a movable part 12 having a wedge-shaped protrusion 11 with its tip facing upward.
is placed in the convex portion 9.
また凸部９の内部上端面には、上記くさび形凸部１１と
嵌合するくさび形凹部１３が設けられている。上記光フ
ァイバｌは、この凸部９の内部上端面とくさび形凸部１
１の先端との間に挿通されている。Further, a wedge-shaped recess 13 is provided on the inner upper end surface of the protrusion 9 to fit into the wedge-shaped protrusion 11 . The optical fiber l is connected to the inner upper end surface of the convex portion 9 and the wedge-shaped convex portion 1.
It is inserted between the tip of 1 and the tip of 1.
ここで、本発明の光ファ・ｒバ液体検知センサが、第３
図に示す従来のらのと異なる点は、可動部１２の移動方
向に垂直な而（第２図中イに示す而）の可動部１２の断
面積か、同じく可動部１２の移動方向に垂直な而（第２
図中口に示す面）の液体膨潤性材料４の断面積と比較し
て小さいところにある。Here, the optical fiber liquid detection sensor of the present invention has a third
The difference from the conventional model shown in the figure is that the cross-sectional area of the movable part 12 is perpendicular to the direction of movement of the movable part 12 (shown in A in Fig. 2), or the cross-sectional area is perpendicular to the direction of movement of the movable part 12. Why (second
The cross-sectional area of the liquid-swellable material 4 is smaller than the cross-sectional area of the liquid-swellable material 4 (the surface shown at the opening in the figure).
この断面積の比率は、可動部Ｉ２の断面積をＡ液体膨潤
性材料４の断面積をＡ、とした場合１、へ。The ratio of this cross-sectional area is 1 when the cross-sectional area of the movable part I2 is A and the cross-sectional area of the liquid-swellable material 4 is A.
／ＡＩが２．０〜１０．０の範囲の乙のが好適である。/AI is preferably in the range of 2.0 to 10.0.
この光ファイバｌは、石英系ガラスファイバ、多成分系
ガラスファイバ、あるいはプラスチックファイバ等の光
ファイバ裸線に、熱硬化性ノリコン、ウレタン、紫外線
硬化型ポリマ等を材料とする１層あるいは２層以上の被
覆を施した光ファイバ素線や、この素線をナイロン等で
被覆した光ファイバ心線が好適に使用される。This optical fiber l consists of a bare optical fiber such as a quartz glass fiber, a multi-component glass fiber, or a plastic fiber, and one or more layers made of thermosetting resin, urethane, ultraviolet curing polymer, etc. Optical fiber strands coated with nylon or coated optical fibers are preferably used.
上記収納部８および凸部９は、例えば表面に多数の孔が
形成されている等の外部の液体が容易に内部に浸透する
材料、もしくは構造となっている。The housing portion 8 and the convex portion 9 are made of a material or have a structure such that, for example, a large number of holes are formed on the surface so that external liquid can easily penetrate inside.
また、液体膨潤性材料４としては、膨潤しやすく、かつ
膨潤時に体積増加量が大きい素材が使用される。またそ
の素材は、検知される液体の種類により異なる。水に対
して好適な材料を例示すれば、ポリ塩化ビニル、ポリエ
チレン、ＥｖＡｌｔ指、ＥＥＡ樹脂、ポリエステル樹脂
、ポリウレタン、スチレン系の熱可塑性エラストマー（
以下、ＴＰＥと略記する）、オレフィン系ＴＰＥ、エス
テル系ＴＰＥ、塩化ビニル系ＴＰＥ、アミド系ＴＰＥ、
ジエン系ＴＰＥ、アイモノマ系ＴＰＥ等の熱可塑性樹脂
、または１，３ジエン系ゴム等のゴムにポリアクリル酸
塩−ポリアクリル酸共重合体、ポリビニルアルコール−
酢酸ビニル共重合体、ポリウレタン、ポリエチレンオキ
サイド、澱粉グラフト共重合体、カルボキシメチルセル
ロース（ＣＭＣ）等の水膨潤性材料を混合したものなど
が好適に使用される。また、使用型は膨潤能力や、体積
膨潤率などを考慮して適宜に決められる。Further, as the liquid-swellable material 4, a material that is easily swollen and has a large volume increase upon swelling is used. The material also differs depending on the type of liquid being detected. Examples of materials suitable for water include polyvinyl chloride, polyethylene, EvAlt fingers, EEA resins, polyester resins, polyurethane, and styrenic thermoplastic elastomers (
(hereinafter abbreviated as TPE), olefin TPE, ester TPE, vinyl chloride TPE, amide TPE,
Polyacrylate-polyacrylic acid copolymer, polyvinyl alcohol, thermoplastic resin such as diene TPE, eye monomer TPE, or rubber such as 1,3 diene rubber.
Mixtures of water-swellable materials such as vinyl acetate copolymers, polyurethane, polyethylene oxide, starch graft copolymers, and carboxymethyl cellulose (CMC) are preferably used. Further, the type to be used is appropriately determined in consideration of swelling ability, volumetric swelling rate, and the like.
この液体膨潤性材料４は、ある程度流動性があるものが
好適であり、流動しにくいものは粒子状にして使用され
るのが好適である。The liquid-swellable material 4 is preferably one that has some degree of fluidity, and those that are difficult to flow are preferably used in the form of particles.
本発明の光ファイバ液体センサの特徴は、少量の液体に
対しても感度良く検知できるところにある。この検知機
構について以下説明する。The optical fiber liquid sensor of the present invention is characterized in that it can detect even a small amount of liquid with high sensitivity. This detection mechanism will be explained below.
まず、この光ファイバ液体検知センサ付近に浸入した液
体は収納部８内に浸透する。収納部８内に浸透した液体
は、液体膨潤性材料４に吸収され、膨潤して体積膨張を
起こし凸部９内を上昇する。First, the liquid that has entered the vicinity of this optical fiber liquid detection sensor permeates into the storage section 8 . The liquid that has permeated into the housing portion 8 is absorbed by the liquid-swellable material 4, swells, causes volumetric expansion, and rises within the convex portion 9.
これにより可動部１２が押しあげられる。押しあｆられ
た可動部！２のくさび型凸部ＩＩは、光ファイバｌと接
触し、これに曲がりを発生させる。この曲がりの発生し
た部分では、伝送光の損失が増大する。この損失増を別
に設けられた図示しない感知部にて感知し、これを液体
の侵入として検知するものである。This pushes up the movable part 12. Moving parts pushed together! The wedge-shaped convex portion II of 2 contacts the optical fiber 1 and causes it to bend. The loss of transmitted light increases in the portion where this bending occurs. This increase in loss is detected by a separately provided sensing section (not shown), and this is detected as an intrusion of liquid.
本発明においては、可動部の移動方向に垂直な面の可動
部１２の断面積をＡい収納部８内の液体膨潤性材料４の
可動部の移動方向に垂直な而の断面積をＡｔ、膨潤率を
α、液体膨潤性材料４の容器８内の肉厚をｈ、膨潤によ
る可動部Ｉ２の移動ｊ且をΔｈとすると、
Δｈ−αｈＡｔ／Ａ
となり、液体膨潤性材料の断面積と可動部の断面積とが
同一である従来の先ファイバ液体検知センサの場合と比
較してＡ、／Ａ１倍の移動量が得られる。ここでＡ 、
＜ Ａ ！であるので、移動量が従来のらのと比べて大
きくなる。これはすなわち検知の感度が良好になったこ
とを示すものである。In the present invention, the cross-sectional area of the movable part 12 in a plane perpendicular to the moving direction of the movable part is A, and the cross-sectional area of the liquid-swellable material 4 in the storage part 8 in a plane perpendicular to the moving direction of the movable part is At. If the swelling rate is α, the wall thickness of the liquid swellable material 4 in the container 8 is h, and the movement j of the movable part I2 due to swelling is Δh, then Δh−αhAt/A is obtained, and the cross-sectional area of the liquid swellable material and the movement Compared to a conventional fiber-optic liquid detection sensor in which the cross-sectional area of each part is the same, the amount of movement A, /A1 times can be obtained. Here A,
<A! Therefore, the amount of movement is larger than that of the conventional ratchet. This indicates that the detection sensitivity has improved.
「実施例」
コア径５０μｍ、ファイバ径１２５μｍ、−次被覆（熱
硬化性シリコン）径４００μ■、二次被覆（ナイロン）
径９００μｍ１屈折率差１％の石英系マルチモードファ
イバ心線を光ファイバｌに用い、液体膨潤性材料４とし
ては、熱可塑性エラストマとポリアクリル酸塩系吸水材
料の混合物を使用した。"Example" Core diameter 50 μm, fiber diameter 125 μm, secondary coating (thermosetting silicone) diameter 400 μm, secondary coating (nylon)
A silica-based multimode fiber core with a diameter of 900 μm and a refractive index difference of 1% was used as the optical fiber 1, and as the liquid-swellable material 4, a mixture of a thermoplastic elastomer and a polyacrylate-based water-absorbing material was used.
収納部８内の液体膨潤性材料４の断面積Ａ、と、可動部
の断面積Ａ、との比率は、Ａ！／Ａ Ｉ” ４．０とし
た。The ratio between the cross-sectional area A of the liquid-swellable material 4 in the storage part 8 and the cross-sectional area A of the movable part is A! /A I” was set to 4.0.
このような光ファイバ液体検知センサを浸水検知センサ
として使用に供した結果、従来のものと比較して少量の
浸水に対しても検知できるようになった。As a result of using such an optical fiber liquid detection sensor as a water immersion detection sensor, it has become possible to detect even a small amount of water immersion compared to conventional sensors.
「発明の効果」
本発明は、光ファイバと、液体を吸収し膨潤する液体膨
潤性材料と、上記光ファイバに該液体膨潤性材料の膨潤
により曲げを生じさせる可動部とからなる光ファイバ液
体検知センサにおいて、可動部の移動方向に垂直面の可
動部の断面積をＡ１、可動部の移動方向に垂直面の液体
膨潤性材料の断面積をＡ、としたとき、Ａ ＋ ＜ Ａ
ｘであることを特徴とした光ファイバ液体検知センサ
であるので、少量の液体が侵入した場合でも液体膨潤性
材料の体積増加による可動部の移動ｍが大きい。よって
、光ファイバに曲げを生じさせることができ、液体の侵
入を検知できる。すなわち、本発明の光ファイバ液体検
知センサは、形状を小さく保ち、かつ感度を向上させた
ものである。従って、少量の浸水事故等に対しても検知
が行える効果を存するものである。"Effects of the Invention" The present invention provides an optical fiber liquid sensing device comprising an optical fiber, a liquid-swellable material that absorbs liquid and swells, and a movable part that causes the optical fiber to bend due to swelling of the liquid-swellable material. In the sensor, when the cross-sectional area of the movable part in the plane perpendicular to the moving direction of the movable part is A1, and the cross-sectional area of the liquid-swellable material in the plane perpendicular to the moving direction of the movable part is A, A + < A.
Since this is an optical fiber liquid detection sensor characterized by x, even if a small amount of liquid enters, the movement m of the movable part due to the volume increase of the liquid swelling material is large. Therefore, the optical fiber can be bent, and the intrusion of liquid can be detected. That is, the optical fiber liquid detection sensor of the present invention has a small size and improved sensitivity. Therefore, it has the effect of being able to detect even small amounts of flooding accidents.
第１図は光ファイバ液体検知センサの実施例を示す概略
斜視図、第２図は実施例を示す概略斜視図、第３図は従
来の光ファイバ液体検知センサを示す概略断面図である
。
１ ・・・・光ファイバ、４ ・・・・液体膨潤性材料
１２ ・・・・可動部、FIG. 1 is a schematic perspective view showing an embodiment of an optical fiber liquid detection sensor, FIG. 2 is a schematic perspective view showing the embodiment, and FIG. 3 is a schematic sectional view showing a conventional optical fiber liquid detection sensor. 1...Optical fiber, 4...Liquid swellable material 12...Movable part,
Claims (1)
と、上記光ファイバに該液体膨潤性材料の膨潤により曲
げを生じさせる可動部とからなる光ファイバ液体検知セ
ンサにおいて、可動部の移動方向に垂直面の可動部の断
面積をＡ＿１、同じく可動部の移動方向に垂直面の液体
膨潤性材料の断面積をＡ＿２としたとき、Ａ＿１＜Ａ＿
２であることを特徴とした光ファイバ液体検知センサ。In an optical fiber liquid detection sensor comprising an optical fiber, a liquid-swellable material that absorbs liquid and swells, and a movable part that causes the optical fiber to bend due to swelling of the liquid-swellable material, in the direction of movement of the movable part. When the cross-sectional area of the movable part in the vertical plane is A_1, and the cross-sectional area of the liquid-swellable material in the plane perpendicular to the moving direction of the movable part is A_2, A_1<A_
2. An optical fiber liquid detection sensor characterized by:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP31072488A JPH02156135A (en) | 1988-12-08 | 1988-12-08 | Liquid detection sensor for optical fiber |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP31072488A JPH02156135A (en) | 1988-12-08 | 1988-12-08 | Liquid detection sensor for optical fiber |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH02156135A true JPH02156135A (en) | 1990-06-15 |
Family
ID=18008714
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP31072488A Pending JPH02156135A (en) | 1988-12-08 | 1988-12-08 | Liquid detection sensor for optical fiber |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH02156135A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2014041054A (en) * | 2012-08-22 | 2014-03-06 | Japan Atomic Energy Agency | Moisture sensor |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63228105A (en) * | 1987-03-17 | 1988-09-22 | Fujikura Ltd | Sensor for detecting water infiltration of optical fiber |
-
1988
- 1988-12-08 JP JP31072488A patent/JPH02156135A/en active Pending
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63228105A (en) * | 1987-03-17 | 1988-09-22 | Fujikura Ltd | Sensor for detecting water infiltration of optical fiber |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2014041054A (en) * | 2012-08-22 | 2014-03-06 | Japan Atomic Energy Agency | Moisture sensor |
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