JPH04148832A - Temperature measuring method and distribution-type optical-fiber temperature sensor - Google Patents
Temperature measuring method and distribution-type optical-fiber temperature sensorInfo
- Publication number
- JPH04148832A JPH04148832A JP2270627A JP27062790A JPH04148832A JP H04148832 A JPH04148832 A JP H04148832A JP 2270627 A JP2270627 A JP 2270627A JP 27062790 A JP27062790 A JP 27062790A JP H04148832 A JPH04148832 A JP H04148832A
- Authority
- JP
- Japan
- Prior art keywords
- light
- optical fiber
- temperature
- measured
- stokes
- 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.)
- Granted
Links
- 239000013307 optical fiber Substances 0.000 title claims abstract description 50
- 238000000034 method Methods 0.000 title claims description 8
- 238000001069 Raman spectroscopy Methods 0.000 claims abstract description 15
- 238000009529 body temperature measurement Methods 0.000 claims abstract description 6
- 238000012545 processing Methods 0.000 claims description 13
- 230000003287 optical effect Effects 0.000 claims description 5
- 239000000126 substance Substances 0.000 claims 2
- 238000005259 measurement Methods 0.000 description 5
- 238000012935 Averaging Methods 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 239000004065 semiconductor Substances 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 230000003595 spectral effect Effects 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
Landscapes
- Measuring Temperature Or Quantity Of Heat (AREA)
- Radiation Pyrometers (AREA)
Abstract
Description
【発明の詳細な説明】
［産業上の利用分野］
本発明は分布型光ファイバー温度センザーに関するもの
である。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a distributed optical fiber temperature sensor.
［従来の技術］
第２図に従来技術の構成を示す。１３はレーザ発光部、
１４は光方向性結合器、１５は被測定光ファイバー、１
６は分光部、１７及び１８は光電変換器、１９及び２０
は前置増幅器、２１は平均化処理部、２２は信号処理部
を表わす。[Prior Art] FIG. 2 shows the configuration of the prior art. 13 is a laser emitting part;
14 is an optical directional coupler, 15 is an optical fiber to be measured, 1
6 is a spectroscopic unit, 17 and 18 are photoelectric converters, 19 and 20
21 represents a preamplifier, 21 represents an averaging processing section, and 22 represents a signal processing section.
光源部のレーザ発光部１３から発振したレーザパルスは
、被測定用の光ファイバー１５へ入射され、光フアイバ
ー１５中で発生したラマン１１々乱光が入射端へ戻って
くる。該ラマン散乱光は光方向性結合器１４により測定
装置へ導光され、まず分光部１６によりラマン散乱光中
のストークス光と反ストークス光が分離検出され、各々
光電変換器１７．１８でその強度に比例した電気信号に
変換される。該電気信号は各々前置増幅器１９．２゜に
より増幅され、平均化処理部２１にて所定回数平均化処
理がなされる。平均化処理された信号は信号処理部２２
へ伝送され、スト−クス光と反ストークス光の信号の比
をとり、温度分布への換算等の処理がなされる。Laser pulses oscillated from the laser emitting section 13 of the light source section are input to the optical fiber 15 to be measured, and the scattered light of the Raman 11 generated in the optical fiber 15 returns to the input end. The Raman scattered light is guided to the measuring device by the optical directional coupler 14, and first the Stokes light and anti-Stokes light in the Raman scattered light are separated and detected by the spectrometer 16, and their intensities are determined by photoelectric converters 17 and 18, respectively. is converted into an electrical signal proportional to . The electrical signals are each amplified by a preamplifier 19.2°, and averaged a predetermined number of times by an averaging processing section 21. The averaged signal is sent to the signal processing unit 22
The ratio of the Stokes light and anti-Stokes light signals is calculated, and processing such as conversion to temperature distribution is performed.
［発明の解決しようとする課題］
従来、上記のような構成の分布型光ファイバ？Ｍ度セン
ザーにおいては以下に示すような温度測定を行なってい
た。[Problem to be solved by the invention] What is the conventional distributed optical fiber having the above configuration? The M degree sensor measures temperature as shown below.
入射レーザパルスによって被測定光ファイバー中で発生
した後方ラマン散乱光が伝搬するときのスト−クス光と
反ストークス光の減衰率差の影響を補正するため、
ａｋｊｎ
の式
にスト−クス光と反スト−クス光の減衰率差αを導入し
た式
％式％
を用いて温度分布を測定していた。ここで、Ｔは測定温
度、Ｏは基準温度、Ｒ’ （Ｔ）は被測定部の相対強度
比、Ｒ’（］は基準温度部の相対強度比、ｋはボルツマ
ン定数、１）はブランク定数、Ｃけ光速、１ノはラマン
トンシフト量、ＸはＷ１１離である。このＪ：うな測定
ノブ法によっても精度良く温度分布を測定できたが、こ
の方法では、基準温度ｅを設定するために被測定光ファ
イバ・−を敷設する４７■に該光ファイバーの−・部も
しくは全部を精度の良い恒温槽に人第１、あらがじめ測
定する温度範囲のストークス光と反スト−クス光の減衰
率を測定しなければならず、また測定部分の減衰率を該
光フアイバー全体に定として適用させていた為、すでに
敷設しである光ファイバーや、極端に特性の異なる部分
を含んだ光ファイバーには適用できず、また光ファイバ
ーの特性の経時変化・敷設状態に起因する温度算出の誤
差を含んでいるという欠点を有していた。In order to correct the influence of the difference in attenuation rate between Stokes light and anti-Stokes light when the backward Raman scattering light generated in the optical fiber under test by the incident laser pulse propagates, the formula of akjn is - Temperature distribution was measured using the formula % formula % which introduced the attenuation rate difference α of light. Here, T is the measurement temperature, O is the reference temperature, R' (T) is the relative intensity ratio of the measured part, R' ( ] is the relative intensity ratio of the reference temperature part, k is the Boltzmann constant, and 1) is the blank constant. , C is the speed of light, 1 is the Ramanton shift amount, and X is W11 distance. Although the temperature distribution could be measured with high accuracy using this J: Una measurement knob method, in this method, in order to set the reference temperature e, the optical fiber to be measured is laid. First, the attenuation rate of Stokes light and anti-Stokes light in the temperature range to be measured must be measured in advance, and the attenuation rate of the measurement part must be measured in advance by placing the entire body in a high-precision thermostatic chamber. Because it was applied as a general rule, it cannot be applied to optical fibers that have already been installed or to optical fibers that include parts with extremely different characteristics. It had the disadvantage of containing errors.
［課題を解決する為の手段］
本発明は、前述の問題点を解決すべくなされたものであ
り、光源より被測定用の光フアイバーへレーザパルスを
入射し、該光ファイバーからの後方ラマン散乱光中に含
まれるス［・−ラス光ど反スト−クス光の強度比と遅れ
時間がら該光ファイバーの距離に関する温度分布を測定
する温度測定方法において、１゛（１、）を距離りにお
ける測定温度、Ｉｇ（Ｌ、）を距離Ｌ、におりるスト−
クス光の検出強度、ＩＡ（Ｌ）を距離１．における反ス
ト−クス光の検出強度、△αをスト−クス光ど反スト−
クス光の減衰率差、ｋをボルツマン定数、１〕をブラン
ク定数、Ｃを光速、っノをラマンシフト量としたとき、
予め測定した光ファイバーのＬ ＝ Ｏの温度から逐次
的に以下の式１式％（１）
により温度分布を測定することを特徴とした温度測定方
法、及び被測定用の光フアイバーへレーザパルスを入射
する光源と、該光ファイバーからの後方ラマン散乱光を
検出器へ導光する光方向性結合器と、該後方ラマン散乱
光中に含まれるストークス光と反ストークス光を検出し
それらの強度比と遅れ時間から該光ファイバーの距離に
関する温度分布を算出する仏号処理部とを備えた分布型
光フアイバー温度センサーにおいて、該信号処理部はＴ
（Ｌ）を距離■−における測定温度、１．（Ｌ）を距離
■、におけるストークス光の検出強度、ＩＡ（Ｌ、）を
距離■−における反スト−クス光の検出強度、Δαをス
トークス光と反ストークス光の減衰率差、ｋをボルツマ
ン定数、１１をブランク定数、Ｃを光速、νをラマンシ
フト量としたとき、予め測定した光ファイバーの１．、
、、 ＝ Ｏの温度から逐次的に以下の式１式％（）
により温度分布を測定することを特徴とした分布型光フ
アイバー温度センサーを提供するものである。[Means for Solving the Problems] The present invention has been made to solve the above-mentioned problems, and involves injecting a laser pulse from a light source into an optical fiber to be measured, and detecting backward Raman scattered light from the optical fiber. In a temperature measurement method that measures the temperature distribution with respect to the distance of the optical fiber from the intensity ratio and delay time of the Stokes light and the Stokes light contained in the optical fiber, 1゛(1,) is the measured temperature at a distance. , Ig(L,) at distance L,
The detected intensity of light, IA(L), is set at a distance of 1. The detected intensity of the anti-Stokes light, △α, is the anti-Stokes light
where k is the Boltzmann constant, 1 is the blank constant, C is the speed of light, and k is the Raman shift amount,
A temperature measurement method characterized by sequentially measuring the temperature distribution from the pre-measured temperature of the optical fiber at L = O using the following equation 1, % (1), and injecting a laser pulse into the optical fiber to be measured. a light source that guides the backward Raman scattered light from the optical fiber to a detector, a light directional coupler that detects Stokes light and anti-Stokes light contained in the backward Raman scattered light, and detects their intensity ratio and delay. In the distributed optical fiber temperature sensor, the signal processing section includes a Buddhist name processing section that calculates the temperature distribution with respect to the distance of the optical fiber from time.
(L) is the measured temperature at distance ■-, 1. (L) is the detected intensity of Stokes light at distance ■, IA(L,) is the detected intensity of anti-Stokes light at distance ■-, Δα is the difference in attenuation rate between Stokes light and anti-Stokes light, and k is Boltzmann's constant. , 11 is a blank constant, C is the speed of light, and ν is the amount of Raman shift, 1. of the optical fiber measured in advance. ,
The present invention provides a distributed optical fiber temperature sensor that measures the temperature distribution sequentially from the temperature of .
［作用］
検出されるレイリー散乱光及びスト−クス光、反スト−
クス光の強度をそれぞれＩＲ（ｌ、）及びＩ、（１，、
）、ＩＡ（＋−）とすると次式で与えられる。[Effect] Detected Rayleigh scattered light, Stokes light, anti-Stokes light
The intensity of the light is expressed as IR(l,) and I,(1,,
), IA(+-), it is given by the following equation.
Ｉ 、（Ｌ）＝ ■１ｌｏ（Ｌ）＊ｅｘｐ［−Σａ−（
Ｔ（ｘ）ｌ ］Ｔ ｓ（１，）＝ Ｉ ５ｏ（Ｌ）
＊ ｅｘ、ｐ ［−Σａ、（Ｔ（ｘ）ｌ ］Ｉ
Ａ（１，、）＝
ここでＩＲｏ（＋−）及びＩ 、、、（Ｌ） 、 Ｉ
Ａａ（Ｌ、■（Ｌ））はそれぞれレイリー散乱光及び
スト−クス光、反スト−クス光の被測定光ファイバーの
レーザ光入射端からの距離りにおける発光強度を、α、
及びαｌｌ、ｆｌＡはそれぞれレイリー散乱光及びスト
−クス光、反ストークス光の被測定光ファイバーにおけ
る減衰率を示す。なお、Ｌは被測定光ファイバーにレー
ザパルスか入射してからそれぞれの散乱光が検出される
までの時間から算出できる。また、絶対温度Ｔの関数に
なっているものはｌＲ度依存かあることを、Σ は距離
０から１．−１までのデータを加算することを意味する
。I, (L) = ■1lo(L)*exp[-Σa-(
T(x)l ]T s(1,)=I 5o(L)
* ex, p [-Σa, (T(x)l ]I
A(1,,)= where IRo(+-) and I , , (L) , I
Aa (L, ■ (L)) is the emission intensity of Rayleigh scattered light, Stokes light, and anti-Stokes light at a distance from the laser light input end of the optical fiber to be measured, respectively, α,
and αll and flA respectively represent the attenuation rates of Rayleigh scattered light, Stokes light, and anti-Stokes light in the optical fiber to be measured. Note that L can be calculated from the time from when a laser pulse enters the optical fiber to be measured until each scattered light is detected. Also, what is a function of absolute temperature T is lR degree dependent, and Σ is a distance from 0 to 1. This means adding data up to -1.
次に、レイリー散乱光とスト−クス光にζＪ、温度依存
がないので
Ｉ １ｌ（Ｌｌ１）＝ Ｉ ｌ＋（１、）＊ ｅｘｐ
［−２＊ａ ＋＋（Ｔ（［、））］Ｉ ｇ（Ｌｌ１）
＝ Ｉ ５（Ｌｌ ＊ ｅｘｐ ［２＊ａ ５ｆＴ（Ｌ
）ｌ ］・ ・・ （７）
であるから（式中−α、 （Ｔ （１，） ）の係数２
は往復の減衰を表わす）、
２＊［α、 （Ｔ （Ｌ） ｌ −α、（Ｔ（Ｌ）ｌ
１ ＝１ｒ＋（Ｉ Ｒ（Ｌ）／ Ｉ ｐ（Ｌ÷１） ＊
Ｉ 、、（Ｌｌ１．）／ Ｉ ｓ（１、））となり、
被測定光ファイバーの任意の点におけるレイリー散乱光
とストークス光の減衰率差が求められる。更に、レイリ
ー散乱光及びスト−クス光、反スト−クス光の波長は数
１０ｎｍＬか離れていないのでこの波長領域における減
衰率の変化は線型だと考えられるので、被測定光ファイ
バーの任意の点におけるストークス光と反ストークス光
の減衰率差が求められることとなる。Next, since Rayleigh scattered light and Stokes light have no ζJ and temperature dependence, I 1l (Ll1) = I l + (1, ) * exp
[-2*a ++(T([,))]I g(Ll1)
= I 5(Ll * exp [2*a 5fT(L
)l]... (7) Since (in the formula -α, the coefficient 2 of (T (1,))
represents the round-trip attenuation), 2*[α, (T (L) l −α, (T(L) l
1 = 1r + (I R (L) / I p (L÷1) *
I,,(Ll1.)/Is(1,)),
The difference in attenuation rate between Rayleigh scattered light and Stokes light at any point on the optical fiber to be measured is determined. Furthermore, since the wavelengths of Rayleigh scattered light, Stokes light, and anti-Stokes light are separated by several tens of nanometers, the change in attenuation rate in this wavelength range is considered to be linear. The difference in attenuation rate between Stokes light and anti-Stokes light is determined.
このようにして求められたストークス光と反ストークス
光の減衰率差△αｆＴ（Ｌ））＝ ２ ｘ［α、＋Ｔ（
Ｌ））−〇、（Ｔ（１、））］を用いて次式に従ってＴ
（０）が既知であればＬ＝Ｏから逐次的に温度分布が得
られることとなる。Difference in attenuation rate between Stokes light and anti-Stokes light obtained in this way △αfT(L)) = 2 x[α, +T(
L))−〇, (T(1,))], T according to the following formula
If (0) is known, the temperature distribution can be obtained sequentially from L=O.
１／Ｔ（Ｌ＋１）＝ １／Ｔ（Ｌ）
−Ｃ＊ ［Ｉｎ （Ｉ −（Ｌ）／ Ｉ ｌ
ｌ（Ｌ＋１）＊ Ｉ Ａ（Ｌ＋１）／ＩＡ（Ｌ）１
−Δα（Ｔ（Ｌ）ｌｌ ・ （９）ここで、Ｃは被
測定光ファイバーの材質とレーザの波長によって決まる
定数である。1/T(L+1)=1/T(L)-C* [In(I-(L)/I l
l(L+1)* I A(L+1)/IA(L)1
−Δα(T(L)ll) (9) Here, C is a constant determined by the material of the optical fiber to be measured and the wavelength of the laser.
即ち、距離りにおける温度はＤａｋｉｎＯ式よりであり
、
同様に距離Ｌ＋１では
であり、
これらの両辺を各々引いてに／ｈｃ１／＝Ｃとおくど、
が得られる。このように、基準温度θを設定する必要が
な（なる。That is, the temperature at a distance is according to the DakinO formula, and similarly at a distance L+1, subtracting both sides of these and setting /hc1/=C,
is obtained. In this way, there is no need to set the reference temperature θ.
［実施例］
本発明の詳細な説明する。第１図は本発明のブロック図
である。１は半導体レーザ等のレーザ発光部、２は光フ
アイバーカブラや音響光学素子等の光方向性結合器、３
は被測定光ファイバー、４は分光フィルター等の分光部
、５及び６．７はレイリー散乱光、ストークス光、反ス
ト−クス光各々の光電変換器、８及び９．１゜は前置増
幅器、１１は平均化処理、１２は信号処理部を示してい
る。[Example] The present invention will be explained in detail. FIG. 1 is a block diagram of the present invention. 1 is a laser emitting unit such as a semiconductor laser, 2 is an optical directional coupler such as an optical fiber coupler or an acousto-optic device, and 3 is a laser light emitting unit such as a semiconductor laser.
is an optical fiber to be measured; 4 is a spectroscopic unit such as a spectral filter; 5 and 6.7 are photoelectric converters for Rayleigh scattered light, Stokes light, and anti-Stokes light; 8 and 9.1° are preamplifiers; 11 12 indicates an averaging process, and 12 indicates a signal processing section.
この測定システムを用いて、以下の処理を行う。The following processing is performed using this measurement system.
被測定光ファイバー３のレーザパルス人別端から５０ｍ
の部分をＬ＝Ｏの点とし、その部分の温度Ｔ（０）を２
５．０℃に保ちスト−クス光強度Ｉ。50m from the laser pulse end of the optical fiber to be measured 3
Let the part be the point L=O, and let the temperature T(0) of that part be 2
Stokes light intensity I kept at 5.0°C.
（０）、レイリー散乱光強度ＩＲ（０）、反ストーク」
ｌ
ス光強度■Ａ（０）を測定し、それらを１．（０）＝１
．１．（０）＝１、Ｉ Ａ（０）＝ １とし規格化した
６Ｌ−１ではＩ ｌｌ（１，）＝ ０．９９８９００、
ＩＲ（１，）＝０．９９８９７３、Ｉ Ａ（１）＝ ０
．９９８８１．１であった。これらの値から（８）式を
用いてスト−クス光と反ストークス光の減衰率差△α（
Ｔ（０）ｌを外挿して求め、Δα（Ｔ（０） ｌ ＝
７．３０７８Ｘ １０−１′となった。従って、（９）
式を用いてＴ（１） ＝ ２５．３°Ｃが求められた。(0), Rayleigh scattered light intensity IR (0), anti-Stokes”
l Measure the light intensity ■A(0) and compare them to 1. (0)=1
．． 1. In 6L-1, which is standardized with (0) = 1 and I A (0) = 1, I ll (1,) = 0.998900,
IR(1,)=0.998973, IA(1)=0
．． It was 99881.1. From these values, the attenuation rate difference △α(
Obtain by extrapolating T(0)l, Δα(T(0)l =
It became 7.3078X 10-1'. Therefore, (9)
T(1) = 25.3°C was determined using the formula.
以上の操作を繰り返して、被測定光ファイバー全体の２
ｋｍにわたって１ｍ間隔で温度分布を測定することが可
能となり、光ファイバー個々の特性や経時変化による特
性の変化を考慮してストークス光と反ストークス光減衰
率差を前もって光フアイバー全体にわたって測定してお
くという操作が省くことができ、測定時間の大幅な短縮
が可能となった。Repeat the above operation to measure the entire optical fiber to be measured.
It is now possible to measure temperature distribution at 1 m intervals over a km distance, and the difference in attenuation rates of Stokes light and anti-Stokes light is measured over the entire optical fiber in advance, taking into account the characteristics of each optical fiber and changes in characteristics over time. The operation can be omitted and the measurement time can be significantly shortened.
発明の効果］ 本発明の効果は次のとおりである。Effect of the invention] The effects of the present invention are as follows.
（１）被測定光ファイバーを敷設する前に該光ファイバ
ーの一部もしくは全部を精度の良い恒温槽に入れ、測定
する温度範囲のストークス光と反ストークス光の減衰率
を測定する必要がなくなった。(1) It is no longer necessary to place part or all of the optical fiber to be measured in a highly accurate thermostatic oven before laying the optical fiber to measure the attenuation rate of Stokes light and anti-Stokes light in the temperature range to be measured.
（２）すでに敷設しである光ファイバーや、極端に特性
の異なる部分を含んだ光ファイバーを被測定光ファイバ
ーとして使用することが可能となった。(2) It is now possible to use optical fibers that have already been installed or optical fibers that include parts with extremely different characteristics as optical fibers to be measured.
（３）光ファイバーの特性の経時変化・敷設状態に起因
する温度算出の誤差を相殺して精度の良い温度測定が可
能となった。(3) Accurate temperature measurements are now possible by canceling out temperature calculation errors caused by changes in optical fiber characteristics over time and installation conditions.
第１図は本発明センサーのブロック図であり、第２図は
従来センサーのブロック図である。
１はレーザ発光部、２は光方向性結合器、３は被測定光
ファイバー、４は分光部、５及び６．７は光電変換器、
８及び９．１０は前置増幅器、１１は平均化処理部、１
２は信号処理部を示している。FIG. 1 is a block diagram of a sensor of the present invention, and FIG. 2 is a block diagram of a conventional sensor. 1 is a laser emitting unit, 2 is an optical directional coupler, 3 is an optical fiber to be measured, 4 is a spectroscopic unit, 5 and 6.7 are photoelectric converters,
8 and 9.10 are preamplifiers, 11 is an averaging processing section, 1
2 indicates a signal processing section.
Claims (2)
を入射し、該光ファイバーからの後方ラマン散乱光中に
含まれるストークス光と反ストークス光の強度比と遅れ
時間から該光ファイバーの距離に関する温度分布を測定
する温度測定方法において、Ｔ（Ｌ）を距離Ｌにおける
測定温度、Ｉ＿Ｓ（Ｌ）を距離Ｌにおけるストークス光
の検出強度、Ｉ＿Ａ（Ｌ）を距離Ｌにおける反ストーク
ス光の検出強度、Δαをストークス光と反ストークス光
の減衰率差、ｋをボルツマン定数、ｈをブランク定数、
ｃを光速、νをラマンシフト量としたとき、予め測定し
た光ファイバーのＬ＝０の温度から逐次的に以下の式 ▲数式、化学式、表等があります▼ により温度分布を測定することを特徴とした温度測定方
法。(1) Inject a laser pulse from a light source into the optical fiber to be measured, and calculate the temperature distribution with respect to the distance of the optical fiber from the intensity ratio and delay time of Stokes light and anti-Stokes light contained in the backward Raman scattered light from the optical fiber. In the temperature measurement method, T(L) is the measured temperature at distance L, I_S(L) is the detected intensity of Stokes light at distance L, I_A(L) is the detected intensity of anti-Stokes light at distance L, and Δα is Stokes The attenuation rate difference between light and anti-Stokes light, k is Boltzmann constant, h is Blank constant,
When c is the speed of light and ν is the amount of Raman shift, the temperature distribution is measured sequentially from the pre-measured temperature of the optical fiber at L = 0 using the following formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ temperature measurement method.
る光源と、該光ファイバーからの後方ラマン散乱光を検
出器へ導光する光方向性結合器と、該後方ラマン散乱光
中に含まれるストークス光と反ストークス光を検出しそ
れらの強度比と遅れ時間から該光ファイバーの距離に関
する温度分布を算出する信号処理部とを備えた分布型光
ファイバー温度センサーにおいて、該信号処理部はＴ（
Ｌ）を距離Ｌにおける測定温度、Ｉ＿Ｓ（Ｌ）を距離Ｌ
におけるストークス光の検出強度、Ｉ＿Ａ（Ｌ）を距離
Ｌにおける反ストークス光の検出強度、 Δαをストークス光と反ストークス光の減衰率差、ｋを
ボルツマン定数、ｈをブランク定数、ｃを光速、νをラ
マンシフト量としたとき、予め測定した光ファイバーの
Ｌ＝０の温度から逐次的に以下の式 ▲数式、化学式、表等があります▼ により温度分布を測定することを特徴とした分布型光フ
ァイバー温度センサー。(2) A light source that injects a laser pulse into the optical fiber to be measured, an optical directional coupler that guides the backward Raman scattered light from the optical fiber to the detector, and Stokes contained in the backward Raman scattered light. In a distributed optical fiber temperature sensor, the signal processing section includes a signal processing section that detects light and anti-Stokes light and calculates a temperature distribution with respect to the distance of the optical fiber from their intensity ratio and delay time.
L) is the measured temperature at distance L, I_S(L) is distance L
I_A(L) is the detected intensity of anti-Stokes light at distance L, Δα is the difference in attenuation rate between Stokes light and anti-Stokes light, k is Boltzmann's constant, h is Blank's constant, c is the speed of light, ν A distributed optical fiber temperature system that is characterized by measuring the temperature distribution sequentially from the pre-measured temperature of the optical fiber at L = 0 using the following formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ where is the Raman shift amount. sensor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2270627A JP2897389B2 (en) | 1990-10-11 | 1990-10-11 | Temperature measuring method and distributed optical fiber temperature sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2270627A JP2897389B2 (en) | 1990-10-11 | 1990-10-11 | Temperature measuring method and distributed optical fiber temperature sensor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH04148832A true JPH04148832A (en) | 1992-05-21 |
| JP2897389B2 JP2897389B2 (en) | 1999-05-31 |
Family
ID=17488725
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2270627A Expired - Fee Related JP2897389B2 (en) | 1990-10-11 | 1990-10-11 | Temperature measuring method and distributed optical fiber temperature sensor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2897389B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113654683A (en) * | 2021-08-16 | 2021-11-16 | 许昌许继软件技术有限公司 | Calibration method and device for distributed optical fiber temperature measurement system |
| CN114046900A (en) * | 2021-11-11 | 2022-02-15 | 许继电气股份有限公司 | Self-adaptive filtering method and device for distributed optical fiber temperature measurement system |
-
1990
- 1990-10-11 JP JP2270627A patent/JP2897389B2/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113654683A (en) * | 2021-08-16 | 2021-11-16 | 许昌许继软件技术有限公司 | Calibration method and device for distributed optical fiber temperature measurement system |
| CN113654683B (en) * | 2021-08-16 | 2023-12-05 | 许昌许继软件技术有限公司 | Calibration method and device for distributed optical fiber temperature measurement system |
| CN114046900A (en) * | 2021-11-11 | 2022-02-15 | 许继电气股份有限公司 | Self-adaptive filtering method and device for distributed optical fiber temperature measurement system |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2897389B2 (en) | 1999-05-31 |
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