JPH0723702Y2 - Water level detector using optical fiber - Google Patents
Water level detector using optical fiberInfo
- Publication number
- JPH0723702Y2 JPH0723702Y2 JP8056790U JP8056790U JPH0723702Y2 JP H0723702 Y2 JPH0723702 Y2 JP H0723702Y2 JP 8056790 U JP8056790 U JP 8056790U JP 8056790 U JP8056790 U JP 8056790U JP H0723702 Y2 JPH0723702 Y2 JP H0723702Y2
- Authority
- JP
- Japan
- Prior art keywords
- optical fiber
- temperature distribution
- water
- water level
- heating element
- 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.)
- Expired - Fee Related
Links
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 title claims description 57
- 239000013307 optical fiber Substances 0.000 title claims description 42
- 238000010438 heat treatment Methods 0.000 claims description 25
- 239000002131 composite material Substances 0.000 claims description 24
- 238000000253 optical time-domain reflectometry Methods 0.000 claims description 8
- 238000005259 measurement Methods 0.000 description 17
- 238000001514 detection method Methods 0.000 description 6
- 125000006850 spacer group Chemical group 0.000 description 4
- 238000004804 winding Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 2
- 238000012423 maintenance Methods 0.000 description 2
- 239000011295 pitch Substances 0.000 description 2
- 238000005452 bending Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 238000004080 punching Methods 0.000 description 1
- 238000002310 reflectometry Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000004078 waterproofing Methods 0.000 description 1
Landscapes
- Measurement Of Levels Of Liquids Or Fluent Solid Materials (AREA)
Description
【考案の詳細な説明】 ［産業上の利用分野］ 本考案は、光ファイバを用いて水位を測定する水位検知
装置に関するものである。DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to a water level detection device for measuring a water level using an optical fiber.
［従来の技術］ ダムあるいは水槽等の水位を測定する水位計には、各種
の水位センサが用いられているが、特に測定ストローク
の大きなものには、センサ本体に、フロート式のような
可動部のある水位検知装置が用いられるのが一般的であ
る。勿論、可動部のない電波式や超音波式などの水位検
知装置も開発され、また水圧検知式の投込みタイプの水
位検知装置も一部使用されると聞く。[Prior Art] Various water level sensors are used in water level gauges for measuring water levels in dams, water tanks, etc., but especially for those with a large measurement stroke, the sensor body has a movable part such as a float type. It is common to use a water level detection device with a certain level. Of course, we heard that water level detectors with no moving parts, such as radio waves and ultrasonic waves, were also developed, and that some water pressure detection type water level detectors are also used.
［考案が解決しようとする課題］ しかし、可動部のある水位計では、浮遊するゴミや錆に
よって、可動部のフロート，滑車等が動かなくなる虞れ
があり、信頼度にやや難がある。また超音波，電波式で
は、その原理上、浮遊物や波立ちの影響を受けやすい欠
点がある。特に、無人測定が要求されるダムでは、その
保守管理の面で問題がある。[Problems to be Solved by the Invention] However, in a water level gauge having a movable part, there is a risk that the float, pulley, etc. of the movable part may become immobile due to floating dust and rust, and reliability is somewhat difficult. In addition, the ultrasonic and radio wave types have a drawback that they are easily affected by suspended matter and waves in principle. In particular, dams that require unmanned measurements have problems in terms of maintenance management.
本考案の目的は、センサ本体の可動部をなくし、浮遊物
があっても精度の高い水位測定を行える水位検知装置を
提供することにある。It is an object of the present invention to provide a water level detection device which eliminates the movable part of the sensor body and can measure the water level with high accuracy even if there are floating substances.
［課題を解決するための手段］ 本考案の光ファイバを用いた水位検知装置は、光ファイ
バと線状発熱体とを内蔵して遮水層を被覆した複合線状
体を、測定対象の空気中から水中に向かって水深方向に
沿って設置された円筒状支柱に巻き付けると共に、その
外周に穴あきの筒状カバーを設けて配設し、該複合線状
体の一端側において上記線状発熱体を発熱体給電装置
に、上記光ファイバを温度分布測定装置に接続し、該温
度分布測定装置によりそのOTDR温度分布測定波形上の水
面を境界とする温度分布の大きく変化する距離位置を水
位レベルとして検知する構成のものである。[Means for Solving the Problems] A water level detecting device using an optical fiber according to the present invention is a device for measuring a composite linear body in which an optical fiber and a linear heating element are built-in and a water-blocking layer is covered. The linear heating element is wound around a cylindrical column that is installed from the inside toward the water along the depth direction and is provided with a cylindrical cover with a hole on the outer periphery thereof, and the linear heating element is provided on one end side of the composite linear body. To the heating element power feeding device, the optical fiber is connected to the temperature distribution measuring device, and the temperature position measuring device makes the water level on the distance position where the temperature distribution greatly changes with the water surface on the OTDR temperature distribution measuring waveform as the boundary. It has a configuration for detecting.
［作用］ 光ファイバと線状発熱体とを内蔵する複合線状体はセン
サ部として、ダム等の測定対象たる水溜部の水深方向に
沿って配置しておくと、一部は水中に没し一部は空気中
に残ることになり、水と空気の熱伝導率の差から、水中
の複合線状体温度は空気中の複合線状体温度に比較して
低くなる。従って、少なくとも測定時において、線状加
熱体（ヒータ線等）により補助的に熱を発生させ、光フ
ァイバを適当に加温するようにしておくと、水面を境界
として光ファイバの線状温度分布が著しく変化するよう
になる。[Operation] When the composite linear body containing the optical fiber and the linear heating element is arranged as a sensor section along the water depth direction of the water reservoir section to be measured, such as a dam, a part of it will be submerged in water. Part of it will remain in the air, and the temperature of the composite linear body in water will be lower than the temperature of the composite linear body in the air due to the difference in thermal conductivity between water and air. Therefore, at least during measurement, if a linear heating element (heater wire, etc.) supplementally generates heat to heat the optical fiber appropriately, the linear temperature distribution of the optical fiber with the water surface as the boundary Will change significantly.
光ファイバ温度分布測定装置は、この光ファイバに沿っ
た線状温度分布を精度良く測定することができる装置で
あり、そのOTDR温度分布測定波形上の水面を境界とする
温度分布の大きく変化する距離位置が認識され、これが
水位レベルとして検出される。The optical fiber temperature distribution measuring device is a device that can measure the linear temperature distribution along this optical fiber with high accuracy, and the distance at which the temperature distribution with the water surface on the OTDR temperature distribution measurement waveform as the boundary changes greatly. The position is recognized and this is detected as the water level.
［実施例］ 以下、本考案を図示の実施例に基づいて説明する。[Embodiment] Hereinafter, the present invention will be described based on an illustrated embodiment.
第１図は、センサ部に用いる複合線状体の例として、光
ファイバ３と線状発熱体４とを内蔵した複合ケーブル７
の断面を示す。FIG. 1 shows, as an example of a composite linear body used in a sensor section, a composite cable 7 having an optical fiber 3 and a linear heating element 4 built therein.
The cross section of is shown.
２はテンションメンバ１を中心に有するスペーサであ
り、このスペーサ２の周囲には、複数条の溝、この例で
は４つの溝2aが、互いに直径方向に対向して形成され、
それらの溝2aの１つには光ファイバ３が、残りの溝の２
つにはヒータ線等の線状発熱体４が収納され、一体化さ
れている。これらテンションメンバ1,スペーサ2,光ファ
イバ３及び線状発熱体４は、複合ケーブル７のコア部を
構成しており、このコア部は水中で使用されるために更
に遮水層５を被覆して防水対策を行った上で、防蝕層６
を施す。Reference numeral 2 is a spacer having the tension member 1 at the center, and a plurality of grooves, four grooves 2a in this example, are formed around the spacer 2 so as to be diametrically opposed to each other.
One of the grooves 2a has an optical fiber 3 and the other of the grooves 2a.
A linear heating element 4 such as a heater wire is housed and integrated in one. The tension member 1, the spacer 2, the optical fiber 3 and the linear heating element 4 form a core portion of the composite cable 7, and the core portion further covers the water-impervious layer 5 for use in water. After taking waterproofing measures, the anticorrosion layer 6
Give.
第２図は、上記複合ケーブル７を利用した水位測定シス
テムを示す。FIG. 2 shows a water level measuring system using the composite cable 7.
10は水位測定対象となるダム等の水溜部に水深方向に沿
って設置された円筒状支柱であり、この円筒状支柱10に
は、その全長に亘り等ピッチで、上記複合ケーブル７が
巻き付けられている。Reference numeral 10 denotes a cylindrical column that is installed along a depth direction in a water reservoir of a dam or the like whose water level is to be measured, and the composite cable 7 is wound around the cylindrical column 10 at an equal pitch over its entire length. ing.
更に複合ケーブル７を巻き付けた円筒状支柱10の外側に
は、パンチングメタル（穴あき板）による筒状カバーが
施されている。Further, a cylindrical cover made of punching metal (perforated plate) is provided on the outside of the cylindrical column 10 around which the composite cable 7 is wound.
筒状カバーは複合ケーブル７に水が接触するように穴が
設けられると共に、複合ケーブル７が波や降雨，降雪，
浮遊物からの損傷を防止するための保護カバーとして作
用するものである。上記実施例において、円筒状支柱10
の表面に複合ケーブル７を巻き付けて使用しているが、
これは、現状の光ファイバ温度分布測定装置８ではその
距離分解能が1m程度なので、巻き付けによって光ファイ
バ長を増やし、水深方向の分解能、つまり水位検出分解
能を上げるためである。The cylindrical cover is provided with a hole so that water may come into contact with the composite cable 7, and the composite cable 7 may have waves, rain, snow,
It acts as a protective cover to prevent damage from floating materials. In the above embodiment, the cylindrical support 10
I use the composite cable 7 wrapped around the surface of
This is because the current optical fiber temperature distribution measuring device 8 has a distance resolution of about 1 m, and therefore the optical fiber length is increased by winding to increase the resolution in the water depth direction, that is, the water level detection resolution.
本実施例水位測定システムの測定時には、水位測定対象
とする水面11が、円筒状支柱10に巻き付けられた複合ケ
ーブル７に接していることが必要である。すなわち、複
合ケーブル７が巻き付けられている円筒状支柱10の領域
が、水位測定領域となる。At the time of measurement by the water level measuring system of this embodiment, it is necessary that the water surface 11 to be measured for the water level is in contact with the composite cable 7 wound around the cylindrical column 10. That is, the area of the cylindrical column 10 around which the composite cable 7 is wound becomes the water level measurement area.
上記円筒状支柱10に巻き付けた複合ケーブル７は、その
上端側が測定端まで延在され、測定端で光ファイバ３と
線状発熱体４とに分離され、光ファイバ３は光ファイバ
温度分布測定装置８に接続され、線状発熱体４は発熱体
給電装置９に接続されている。The composite cable 7 wound around the cylindrical column 10 has its upper end side extended to the measurement end, and is separated into the optical fiber 3 and the linear heating element 4 at the measurement end. The optical fiber 3 is an optical fiber temperature distribution measuring device. 8 and the linear heating element 4 is connected to the heating element power feeding device 9.
発熱体給電装置９は、線状発熱体４に給電して発熱さ
せ、また光ファイバ温度分布測定装置８はOTDR（Optica
l Time Domain Reflectometry）装置と同じ手法により
光ファイバ３に沿った温度分布を測定する。The heating element power feeding device 9 feeds power to the linear heating element 4 to generate heat, and the optical fiber temperature distribution measuring device 8 uses the OTDR (Optica).
The temperature distribution along the optical fiber 3 is measured by the same method as that of the Time Domain Reflectometry) device.
今、第２図の如く円筒状支柱10の水位測定領域と途中に
水面11が在る場合、水面11を境界にして光ファイバ３の
温度分布が大きく変化することになる。何故なら、水面
11より上の領域では線状発熱体４による熱的影響が支配
的で光ファイバ３が昇温し、水面下の領域では水による
冷却作用の方が支配的となって光ファイバ３の温度が低
くなるからである。As shown in FIG. 2, when the water surface 11 exists in the middle of the water level measurement area of the cylindrical support 10, the temperature distribution of the optical fiber 3 changes greatly with the water surface 11 as the boundary. Because the water surface
In the region above 11, the thermal effect of the linear heating element 4 is dominant and the temperature of the optical fiber 3 rises, and in the region below the water surface, the cooling action by water is dominant and the temperature of the optical fiber 3 is Because it will be low.
光ファイバ温度分布測定装置８は、光ファイバ３の温度
分布を測定し、上記水面11を境界とする温度分布の大き
く変化する地点を認識することにより、水位（水面位
置）を検出する。詳述するに、光ファイバ温度分布測定
装置８は、内蔵する光源からセンサ用光ファイバ３に、
その一端よりパルス光を入射する。この光はセンサ用光
ファイバ３中を伝播し、その各通過位置で後方散乱光を
発生させる。この後方散乱光の一部は、上記センサ用光
ファイバ３の入射端側に戻って来る。光ファイバ温度分
布測定装置８のOTDR測定系は、この後方散乱光をOTDR測
定し、その後方散乱光のストークス光とアンチストーク
ス光との光強度比の時間変化より、センサ用光ファイバ
３に沿った線状の温度分布を測定する。The optical fiber temperature distribution measuring device 8 detects the water level (water surface position) by measuring the temperature distribution of the optical fiber 3 and recognizing the point where the temperature distribution greatly changes with the water surface 11 as a boundary. More specifically, the optical fiber temperature distribution measuring device 8 is provided with a sensor optical fiber 3 from a built-in light source.
Pulsed light enters from one end thereof. This light propagates through the sensor optical fiber 3 and generates backscattered light at each passage position thereof. A part of the backscattered light returns to the incident end side of the sensor optical fiber 3. The OTDR measurement system of the optical fiber temperature distribution measuring device 8 measures the backscattered light by OTDR, and determines the time along the optical fiber 3 for sensor from the time change of the light intensity ratio between the Stokes light and the anti-Stokes light of the backscattered light. Measure the linear temperature distribution.
第３図は、光ファイバ温度分布測定装置８による測定温
度グラフを示す。第３図の横軸の左端は上記円筒状支柱
10の水位測定領域の最下限、右端は最上限に当る。第２
図の水面11に対応して、OTDR温度分布測定波形12は、そ
の波形の途中で急峻に立ち下がる波形変化を生じてお
り、この急な温度下降の生ずる地点、つまり原点（最下
限）からの距離位置13が、水位レベルであるとして検出
される。FIG. 3 shows a temperature graph measured by the optical fiber temperature distribution measuring device 8. The left end of the horizontal axis in FIG. 3 is the cylindrical column.
The lower limit of the water level measurement area of 10 is the upper limit at the right end. Second
Corresponding to the water surface 11 in the figure, the OTDR temperature distribution measurement waveform 12 has a waveform change that sharply falls in the middle of the waveform, and the point where this sudden temperature drop occurs, that is, the origin (the lowest limit) Distance position 13 is detected as being at the water level.
上記の温度分布測定に際し、発熱体給電装置９は線状発
熱体４を常時給電して発熱させていても良いが、エネル
ギーの損失を考慮した場合、あまり得策でない。そこで
省エネルギー化を図るため、通常は、水温と気温の差で
温度分布測定波形上の変化点の距離位置を自動測定し、
判定のつかない時にのみ、最小限のエネルギーでヒータ
加熱をする。In the above temperature distribution measurement, the heating element power feeding device 9 may constantly feed power to the linear heating element 4 to generate heat, but this is not a good idea when energy loss is taken into consideration. Therefore, in order to save energy, normally, the distance position of the change point on the temperature distribution measurement waveform is automatically measured by the difference between the water temperature and the air temperature,
Only when there is no judgment, heat the heater with the minimum energy.
尚、複合ケーブル７の巻き付けは、マイクロベンドによ
る著しい光損失を光ファイバ３に与えないような許容曲
げ半径を満足していれば良い。従って、円筒状支柱10は
円柱でも角柱でも良い。また、巻き付けのピッチは等ピ
ッチでなくとも、測定時にソフトで対応させることがで
きる。It should be noted that the winding of the composite cable 7 only needs to satisfy an allowable bending radius that does not give the optical fiber 3 a significant optical loss due to the microbend. Therefore, the cylindrical column 10 may be a column or a prism. Moreover, even if the winding pitches are not equal, it is possible to use software at the time of measurement.
［考案の効果］ 以上述べたように、本考案は、線状発熱体により発生し
た熱を光ファイバで検知させるため、線状発熱体と光フ
ァイバを内蔵した複合線状体をセンサ部とし、これと光
ファイバ温度分布測定装置とを組み合わせて、温度の急
峻な変化部を見い出すことにより水位を検知するもので
ある。従って、次のような優れた効果を奏する。[Advantages of the Invention] As described above, the present invention detects the heat generated by the linear heating element with the optical fiber, and thus the composite linear body including the linear heating element and the optical fiber is used as the sensor unit. By combining this with an optical fiber temperature distribution measuring device, the water level is detected by finding a steep temperature change portion. Therefore, the following excellent effects are obtained.
（１）可動部がないため故障が少なく、保守が容易であ
る。(1) Since there are no moving parts, there are few failures and maintenance is easy.
（２）浮遊物の影響を受けない。(2) Not affected by suspended matter.
（３）凍結時にも、線状発熱体の発熱量を制御すること
により測定が可能である。(3) Even when frozen, measurement can be performed by controlling the amount of heat generated by the linear heating element.
第１図は本考案の実施例におけるセンサ部の複合ケーブ
ルの断面図、第２図は本考案の実施例の水位検知装置の
構成図、第３図は光ファイバ温度分布測定装置で測定さ
れる線状温度分布を例示した図である。 図中、１はテンションメンバ、２はスペーサ、３は光フ
ァイバ、４は線状発熱体、５は遮水層、６は防蝕層、７
は複合ケーブル（複合線状体）、８は光ファイバ温度分
布測定装置、９は発熱体給電装置、10は円筒状支柱、11
は水面、12はOTDR温度分布測定波形、13は温度下降箇所
（距離位置）を示す。FIG. 1 is a cross-sectional view of a composite cable of a sensor unit in an embodiment of the present invention, FIG. 2 is a configuration diagram of a water level detection device in an embodiment of the present invention, and FIG. 3 is measured by an optical fiber temperature distribution measuring device. It is the figure which illustrated linear temperature distribution. In the figure, 1 is a tension member, 2 is a spacer, 3 is an optical fiber, 4 is a linear heating element, 5 is an impermeable layer, 6 is an anticorrosion layer, 7
Is a composite cable (composite linear body), 8 is an optical fiber temperature distribution measuring device, 9 is a heating element power feeding device, 10 is a cylindrical column, 11
Is the water surface, 12 is the OTDR temperature distribution measurement waveform, and 13 is the temperature falling point (distance position).
Claims (1)
層を被覆した複合線状体を、測定対象の空気中から水中
に向かって水深方向に沿って設置された円筒状支柱に巻
き付けると共に、その外周に穴あきの筒状カバーを設け
て配設し、該複合線状体の一端側において上記線状発熱
体を発熱体給電装置に、上記光ファイバを温度分布測定
装置に接続し、該温度分布測定装置によりそのOTDR温度
分布測定波形上の水面を境界とする温度分布の大きく変
化する距離位置を水位レベルとして検知することを特徴
とする光ファイバを用いた水位検知装置。1. A cylindrical support in which a composite linear body having an optical fiber and a linear heating element built-in and having a water-impervious layer coated is installed along the depth direction from the air to be measured into the water. And a cylindrical cover with a hole on the outer periphery thereof is provided, and the linear heating element is connected to a heating element power feeding device and the optical fiber is connected to a temperature distribution measuring device at one end of the composite linear element. A water level detecting device using an optical fiber, wherein the temperature distribution measuring device detects, as a water level, a distance position at which the temperature distribution on the OTDR temperature distribution measuring waveform greatly changes with the water surface as a boundary.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8056790U JPH0723702Y2 (en) | 1990-07-31 | 1990-07-31 | Water level detector using optical fiber |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8056790U JPH0723702Y2 (en) | 1990-07-31 | 1990-07-31 | Water level detector using optical fiber |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0438526U JPH0438526U (en) | 1992-03-31 |
| JPH0723702Y2 true JPH0723702Y2 (en) | 1995-05-31 |
Family
ID=31625747
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP8056790U Expired - Fee Related JPH0723702Y2 (en) | 1990-07-31 | 1990-07-31 | Water level detector using optical fiber |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0723702Y2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH11304739A (en) * | 1998-04-16 | 1999-11-05 | Kasen Joho Center | Wetness distribution measurement method |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114295177B (en) * | 2021-12-31 | 2024-08-30 | 北京景通科信科技有限公司 | Well lane water level detection method based on distributed optical fibers |
-
1990
- 1990-07-31 JP JP8056790U patent/JPH0723702Y2/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH11304739A (en) * | 1998-04-16 | 1999-11-05 | Kasen Joho Center | Wetness distribution measurement method |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0438526U (en) | 1992-03-31 |
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