JPH02171628A - Measuring apparatus - Google Patents

Abstract

PURPOSE:To enable accurate measurement of positions, temperatures and the like of measuring sections accurately by making a light signal incident with the application of reference signal of a position, temperature, humidity and the like between measuring sections of an optical fiber to correct actually measured values from intensity of back scattered light from parts where the reference signal are applied. CONSTITUTION:An optical fiber 22 is laid in an area 20 to be measured across measuring sections 21a-21n and reference signal applying means 23a-23n are arranged between measuring sections. A pulse S is directed into the fiber 22 from a light source 11 and a back scattered light is processed with a data processor 14 through a characteristic filter or a branching filter 12. Thus, the back scattered light is detected at a point where reference signals are applied to specify the measuring sections 21a-21n from reference positions thereof, thereby enabling accurate measurement of temperatures.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Field of Application) The present invention involves inputting an optical signal from an input end, which is one end, in an optical fiber laid in a measurement area, and transmitting an optical signal to the other end. The present invention relates to a 4111 constant device that measures temperature, humidity, temperature distribution, etc. at any location within the Al11 constant region by analyzing backscattered light returning to the incident end from any direction.

(Prior art and problems to be solved by the invention) Generally, when a material is irradiated with an optical signal of a certain frequency ω,
This optical signal is scattered backwards by the material and returns,
The returned light is collected using a time domain analyzer (hereinafter referred to as 0T), for example.
DR), in addition to the frequency ω of the irradiated light, ω+ωr and ω±mωr (+
is an integer), that is, Raman (Raman
) A phenomenon involving scattered light was discovered by Raman, but it has since been known that this Raman scattered light is dependent on temperature.

By the way, this Raman scattering is affected by microscopic substances and various molecules in the air or gas environment, so it has been thought that it is difficult to use it for temperature measurement. However, since then, with the development of optical fiber manufacturing and technology, research has been conducted into various ways to use optical fibers, and research and development has also progressed into the use of thermometers. In particular, unlike air or gas environments, optical fibers only have a fixed fiber component, so it has gradually become clear that they are suitable for temperature measurement. However, at present, thermometers based on 0TDR that utilize backscattering have a position resolution length Lt of the optical fiber in the measuring section.
is 20m1 Minimum measurement temperature Tb is 5°C1 Maximum measurement temperature T
c is 150℃ (due to the operating temperature limit of optical fiber)
, the minimum refresh time T rfr is 90 seconds
(determined by OTDR and temperature measurement method), maximum measurement length LtIIlx is in the range of 1lv (due to the resolution of OTDR), etc., but even if we predict the future, at most Lt-w2, Tb-2 ℃ degree, Tc -500~6
00°C, Trfr - about 30 seconds, and L tmx - about several km.

Therefore, at present, since Lt >20 m, it is difficult to measure the temperature at a point, and the only research that has been done is to measure the temperature distribution along the optical fiber.

Moreover, the backscattered light from each point on a long optical fiber is weak and contains noise, so the optical signal is emitted thousands to tens of thousands of times and the backscattered light is averaged to eliminate the noise. Although the structure is designed to measure the desired signal by removing the signal, it is extremely difficult to measure with good fidelity. Also, 0TD
R originally has the function of detecting position, but due to temperature changes, the optical refractive index within the optical fiber, which is the optical transmission path, changes, and the transmission speed of light within the fiber changes accordingly. Therefore, even if the conventional method of calculating the temperature detection position from the light transmission time is used as is, the temperature detection position cannot be accurately identified. Note that one of the reasons for requiring a length of Lt>20 m is due to changes in the transmission speed of light. Therefore, the predetermined dl1
1. When used in a constant temperature environment at a fixed location and measuring abnormal temperatures that occur locally, the temperature detection location and the temperature at that location can be measured fairly accurately while taking those known conditions into account. However, in the case of general temperature aj determination, which measures the temperature at an unspecified location, various problems arise as described above.

The present invention has been made in view of the above circumstances, and it is possible to measure the temperature at any arbitrary location in a wide range of measurement areas.

It can accurately measure humidity and temperature distribution in the measurement area,
Furthermore, it is an object of the present invention to provide a 71111 constant device that can improve the measurement sensitivity and resolution of measured values and contribute to speeding up data processing.

[Structure of the invention] (Means for solving the problem) In order to solve the above problem, the present invention provides claims] and 2.
In , an optical signal is input from a light source to the input end of an optical fiber, and the time required for Raman scattering generated within the optical fiber due to the input of this optical signal until backscattered light directed toward the input end returns. In a measuring device that measures temperature, humidity, or temperature distribution by analyzing the strength of the returned signal with a signal processing device, the measuring section of the optical fiber is continuously arranged across each IPj fixed location in the measurement area. In addition, the configuration includes a reference signal applying means for applying reference signals such as position and temperature over a part or all of the apj constant section.

Further, in claim 3, the optical fiber is covered with 'A11l.
The optical fibers are arranged in a predetermined order in a single stroke in a two-dimensional or three-dimensional manner in a predetermined area, and all or part of the intersecting portions or any part of the non-intersecting portions formed on the optical fibers are defined as measurement portions. Applying a reference signal and inputting an optical signal to the input end of the optical fiber, and determining position data or position data and temperature data of the measuring section from the backscattered light obtained by the input of the optical signal at this time. The temperature, humidity, or temperature distribution of the n1 constant part is calculated using the position and temperature data stored in advance at the actual p1 constant time and the backscattered light obtained by actually inputting the optical signal into the optical fiber. The configuration is such that the data is measured, compared with the stored data, and corrected.

Furthermore, in claim 5, when the area from the signal processing device including the light source to the front of the measurement target area or the optical fiber part excluding any measurement area is defined as a measurement-unnecessary part, the signal processing device il'e of the backscattered light returned from the optical fiber portion corresponding to the measurement-unnecessary portion.
The temperature is determined by skipping the J constant and taking in the backscattered light scattered from within the optical fiber of the part to be measured placed in the AF J constant area.

It is configured to measure humidity or temperature distribution.

Furthermore, in claim 6, the measurement section of the optical fiber is continuously arranged across each of the 4P1 fixed locations in the measurement area, and a variable reference signal is provided over a part or all of the measurement section. A reference signal applying means for applying the reference signal is provided, and the signal processing device controls the reference signal of the reference signal applying means so as to match the actual Jll value of the backscattered light obtained from the optical fiber. .

Furthermore, '!' of the optical fiber in the Apl fixed area. 11
In addition to arranging a constant part, a reference signal applying means for applying a reference signal over a part or the entire area of the measuring part is provided, and the reference signal applying means corresponds to the reference signal applying means by inputting the optical signal to the optical fiber. This is a configuration in which the transmission time of the optical signal within the destination fiber is obtained from the backscattered light that is scattered and returned from the part.

(Function) Therefore, in claim 1, by taking the above measures, the position, temperature, An optical signal is input into an optical fiber while a reference signal such as humidity is applied, and the backscattered light from the reference signal application section is included in the backscattered light scattered from within the optical fiber. Therefore, using the backscattered light from the reference signal application section as a guide, determine from which location the backscattered light returned from the measurement section, and in the case of a reference temperature signal, determine the backscattered light from the reference signal application section. By correcting the actual measured value as a known temperature base, the position and temperature of each measuring section can be accurately measured.

In addition, in claim 3, optical fibers are arranged in a plane or three-dimensionally in a single stroke in a fixed area to be illuminated, and a reference signal is applied to a Δ1 constant part such as a crossing part or a non-crossing part to measure them. Since the reference position or reference position and reference temperature are obtained from the unique backscattered light from the
In actual Ap1, the temperature or humidity can be accurately determined by locating a large number of flFJ constant positions in a wide range using the reference position or the like.

In addition, in claim 5, the area from the signal processing device including the light source to the front of the measurement area or any arbitrary area 71
If the optical fiber part excluding the P+ constant area is set as an unnecessary part of aPJ constant, it can be skipped without processing the ifl constant unnecessary part during actual measurement, so it is possible to reduce the memory capacity and enable high-speed processing. can.

Furthermore, in claim 6, each aP is
By controlling the reference signal of the inter-I fixed section applied signal applying means so as to match the actual measurement value, the actual measurement value can be used as it is as the measurement value.

Furthermore, in claim 7, a reference signal is applied to a specific portion of the measurement area of the optical fiber, and the transmission time of the optical signal within the optical fiber can be obtained from the arrival of backscattered light corresponding to the reference signal.

(Example) Before describing the embodiments of the device of the present invention, the measurement principle applied in the device will be described below. In other words, in Raman scattering applied to this device, when light with a frequency ω irradiates a substance with a frequency ωr such as molecular vibration or lattice vibration, the substance emits scattered light with a frequency ω+ωr in addition to the frequency ω. appear. In particular, when a strong laser beam is input, a strong ω+ωr or ω±m is generated due to stimulated emission.
Oscillations with a frequency of ωr (m is an integer) occur, and these ω
+ωr or ω±mωr occurs anywhere within the optical fiber, and backscattering in the direction of the laser input end also occurs.

Then, ωr and mωr included in this backscattered light
Since the strength of etc. depends on the temperature, this strength is
By performing appropriate processing, information such as position and temperature can be obtained.

FIG. 1 is a diagram showing the measurement principle of a thermometer using 0TDR, which is the basis of the present invention. This Dj constant is determined by a light source 11 such as a laser oscillation device or a light emitting diode that generates a light pulse.
When a light pulse S is generated from a beam splitter 12 (a device that performs the same function as a beam splitter, such as an optical splitter, is also called a beam splitter) and enters the input end of an optical fiber 13, within this optical fiber 13, Transmission arrival position of optical pulse S, for example, t1+...tn
-1°tn, Raman scattering with frequencies of ω+ω", ω+mω" occurs one after another, resulting in each position tI+...
The backscattered light from tn-1tn returns to the input end of the optical fiber, is reflected by the beam splitter 12, and enters the signal processing device 14. Therefore, this signal processing device 1
4, after the light pulse S is generated, each position t1. ...tn-
Let Tl,...Tn-1,Tn be the temperature that is the magnitude of backscattered light scattered from 1,tn, and temporarily Tl -T2-
-----.--Tn-1-Tn, the signal becomes smaller because the farther the temperature is located, the greater the loss due to transmission. That is, the Ap1 fixed connection node 2 by the signal processing device 14 becomes as shown in FIG. Note that since the signal processing device 14 issues a light pulse emission command to the light source 11, in this embodiment, this emission command and the backscattered light scattered and returned from within the optical fiber 13 are processed as electrical signals that can be processed respectively. Convert to , measure the time for the backscattered light to return based on the launch command, calculate the intensity of the backscattered light on the time axis, and calculate the speed of light in the optical fiber as known. Then, the temperature δIII is determined from the measurement position and the intensity of backscattered light at the measurement position.

In other words, this 71111 constant principle is a method of generating a light pulse S and measuring the time until it returns from within the optical fiber 13 to find out where Raman scattering has occurred. In the case of S, if the time between the emitted pulse and the return pulse is long to a certain extent, it is difficult to calculate all the time, so it is effective for long optical fibers. On the other hand, AC to 0TDR
Similarly, when using a continuous wave (modulated wave), there is a method of determining at which position Raman scattering has occurred based on the phase shift between the AC waveform optical signal and the AC waveform optical signal returning from within the optical fiber. , in this case, 71111 can be accurately determined even for a relatively short optical fiber. In either case, the temperature is measured from the magnitude of backscattered light. In addition to the frequency ω of the optical pulse S generated from the light source 11, this backscattered light includes
Since ωr, mω, etc. are mixed, a characteristic filter or branching filter is provided in the signal processing device 14, and after separating ω, ωr, lJr with this characteristic filter or branching filter, the temperature factor is ``ωr'' or ``IIlω''
Alternatively, take out "ωr and lJr" and measure the temperature.

On the other hand, it is also desirable to utilize ωr and mω' when detecting the position. Note that the beam splitter 12 is not necessary when using an element that serves both as a light source that generates an optical signal and as a detector.

Next, FIG. 3 is a diagram particularly showing an example of a single unit of the signal processing section 14. In FIG. That is, this signal processing device 14 includes a CPU 1 that outputs various commands based on a sequence program.
41, and upon receiving an operation command from the CPU 141, when a light pulse of frequency ω is input from the light source 11 to the optical fiber 13 via the beam splitter 12, which is composed of two prisms, for example, inside the optical fiber 13, Of the Raman scattering that occurs, the frequency “ω” that returns to the light input end side
, "ωrJ, rmω", etc. enters the characteristic filter or demultiplexer 142. If 142 is a characteristic filter, use a filter that passes only "ωr" or "lJr", and use one of αω", β m (lJr as a signal, or pass both "ωr" and "lJr". It is passed through a filter and αωr+β ωr is used as a signal. α and β are attenuation coefficients in the filter.

If 142 is a demultiplexer, the light of the frequency "ω" and the light of "ωr"
After the light is separated into light having frequencies of "J and rmωr", the light is converted into electrical signals by subsequent optical-to-electrical converters 143 and 144, respectively. The electrical signal converted by the optical-to-electrical converter 144, that is, the signal caused by Raman scattering, is sent directly or through a switch circuit 145 to a high-speed time series processing means 146.
Here, based on the timing signal input in synchronization with the operation command output from the CPU 141 to the light source 11, the signal strength corresponding to the total time (position) lPJ and the temperature with respect to that time is measured, and the internal memory are saved sequentially. 147 is a data processing unit that performs desired data processing using the data stored in the high-speed time series processing means 146 and, if necessary, data in a file 148 that maps, for example, temperature sources in the ΔIII fixed area. It is.

Next, each embodiment of the device of the present invention will be described using the device as described above. First, FIG. 4 shows claim 1 of the present invention.
FIG. 2 is a diagram showing an example related to No. 2; In the same figure, 20
is a measurement area corresponding to, for example, a building, tank, etc. to be measured for temperature, and this measurement area 20
There are measuring sections 21a, 21b, etc., which serve as multiple measurement locations.
- The optical fiber 22 is continuously laid across 21n. And each measurement part 21a-21b, 21b-
21c (not shown), ... without drawing out or pulling out the optical fiber portion located between the two, the drawn out portion of the optical fiber or the undrawn out portion, etc., is kept sufficiently away from the temperature of 20° C. Temperature 1 e.g. 0℃
Reference signal applying means 23a, 23b, which sets the temperature of
...is provided.

Reference numeral 24 denotes an end non-scattering part, and specifically, the end part of the optical fiber 22 is inserted into a liquid such as silicone oil or paraffin oil to prevent large reflection of light toward the incident end side. This has the function of diffusing most of the light at the end of the optical fiber into the liquid. Suppose that the backscattered light reflected at this terminal part is transmitted to the signal processing device 1.
If amplification is performed on the 4 side, the amplifier becomes saturated and measurement becomes impossible. To avoid this, an embodiment in which a terminal non-scattering section 24 is provided is shown. Although the measurement units 21a, 21b, . . . and the reference signal applying means 23a, 23b, .

Therefore, according to the configuration of the embodiment as described above, the light source 11
When a light pulse S is inputted into the optical fiber 22 from the optical fiber 22 and the backscattered light returned from within the optical fiber 22 is processed by a characteristic filter or demultiplexer 142, the frequency ωr as shown in FIG. 5 is obtained.

The intensity of the backscattered light of mωr is obtained. In this FIG. 5, 25a, 25b, . . . correspond to the temperature (intensity) from each measurement part 21a, 21b, . Means 23a
, 23b, .
23b, . . . indicates a temperature of 0° C. Therefore, the high-speed time series processing means 146 obtains an analog signal proportional to the backscattered light as shown in FIG.

21b, . . . and can accurately measure the temperature.

Note that the reference signal applying means 23a, 23b, . . .
Although position identification is performed by setting a temperature sufficiently far from the temperature of the DI fixed place, for example, if a predetermined reference temperature that is not much different from the temperature of the DI fixed place is set in advance or during actual measurement, the signal processing device 14 Then, each measurement unit 21a, 21 is determined based on the intensity of backscattered light caused by the reference temperature signal.
The actual 1111J temperature of b,... can be corrected,
It can also be used as a reference position signal. Further, although the reference signal applying means 23a and 23b have a fixed reference temperature, they may be of a variable type. In this case, temperature correction can be performed more accurately.

Furthermore, although the optical fiber 22 is illustrated as being laid continuously in one direction, the manner in which it is laid varies depending on the object to be measured. For example, when a tank is used as the region 20 to be measured, the optical fiber 22 is laid in a coil shape inside or outside the tank depending on the shape of the tank. At this time, in the case of inside a tank, as shown in FIG. 6, each average temperature tl of the measurement parts 21a, 21b, .

t2. When measuring ..., in order to clearly distinguish the position from other circumferential parts, segmented winding fibers 27a, 27b, etc. are provided between adjacent circumferential parts to obtain a reference position signal. You may also obtain Therefore, in this case the segmentally wound fiber 27a.

The measuring sections 21a, 2], b extend over a wide distance in each circumferential portion, except for the portions 27b....

... are provided, so if the signals from the measurement parts 21a, 21b, ... of each of these circumferential parts are averaged,
Accurate average temperature of each circumferential portion tl, t2. ... can be measured. Note that the optical fibers 22 of the measurement units 21a, 21b, . . . may be wound circularly only once, or may be wound multiple times. For example, if a pond is to be fixed, the optical fiber 22 can be connected along the shape of the pond.
Needless to say, it is necessary to provide

Therefore, in the embodiment shown in FIG. 6 as well, position signals can be extracted from the segmented winding fibers 27a, 27b, . . . , so that not only the average temperature but also the temperature at a specific position can be determined.

Next, FIG. 7 is a block diagram showing another embodiment of the present invention, which is structurally similar to FIG. 21
c (not shown) connecting portions 28a, 2 including welded portions etc.
8b, . . . are provided, and these connecting portions 28a, 28b, .
- Intensities 29a and 29b of the backscattered light shown in FIG. 8 reflected back from.

The configuration is such that a reference position signal is obtained from . . . , and the position of each measuring section 21a, 21b, . Note that this connection part does not necessarily need to be provided between all measurement parts.

Next, FIGS. 9 to 12 are diagrams showing an embodiment according to claim 3 of the present invention. First, in FIG. 9, the optical fibers 22 are laid in a meandering manner in one direction in a predetermined order so as to form a single stroke on a plane within the measurement area 20, and then meandering in a direction perpendicular to the prescribed order. By laying the optical fibers 22 in a shape, the optical fibers 22 are formed into a mesh shape, and each crossing portion is used as a measurement portion 31a, 31b, . . . .

On the other hand, FIG. 10 shows an optical fiber 22 having a three-dimensional configuration by providing multiple stages of mesh-like optical fibers formed in the same manner as in FIG. 9 at predetermined intervals in the vertical direction. It is. FIG. 11 is a diagram schematically representing the configuration of FIG. 10.

Therefore, when the optical fiber 22 arranged as shown in FIG. 9 and FIG.
The temperatures of 1a, 31b, . . . are measured.

First, only position or position and temperature reference signals are acquired from each measuring section 31a, 31b, . . . .

In this case, each measuring section 31a, 31b.

... individually or all at a temperature sufficiently different from the temperature in the measurement area 20,
is driven to input a light pulse S into the optical fiber 22. Then, the intensity of backscattered light that is Raman scattered from within the optical fiber 22 and returned to the input end side by the incidence of this optical pulse S is filtered by a characteristic filter or a demultiplexer 142. The signal is taken in by a high speed time series processing means 146 through an optical-to-electrical converter 145 and processed in time series. At this time, each measuring section 31a.

31b, . . . for a predetermined time t as shown in FIG. 12(a),
, t2. ...Backscattered light with a different intensity (reference temperature) from each part (reference position) comes in, so the time (reference position) and the temperature for that time are sequentially stored in memory. .

Once the reference position and reference temperature of each measuring section 31a, 31b, .

A light pulse S1 is simply introduced into the input end of the optical fiber 22 without setting a specific temperature, and the reference time (for example, 111 constant part 3
1a) The temperature of the measuring section 31a can be accurately measured based on the intensity of the backscattered light returning from within the optical fiber 22 at the appropriate time (see FIG. 12(b)) and the reference temperature. Another measuring section 31b.

31C1... can also be subjected to similar processing to accurately determine the temperature 71111.

In addition, in FIG. 9 and FIG. 10, the entire mesh-like intersecting part is used as the measurement part, but it may be a part, or the part outside the intersecting part may be used as the measuring part. It may be an ipt constant part, and it does not necessarily have to be mesh-like, and may be, for example, connected by diagonal lines within a polygon.

Next, the thirteenth embodiment regarding the fourth embodiment of the present invention will be explained.
This will be explained with reference to FIGS. 15 to 15.

That is, in this embodiment, the measuring section 40 (21a.

21b, -, 31a, 31b, -=), the optical fibers 22 are laid in a bundle by repeating them multiple times in one stroke. Therefore, when the measuring section 40 is expanded,
The part a of the measuring section 40 is located at the position a1 as shown in FIG. 14(a). a2+...relationship.

Therefore, according to the arrangement of the optical fiber 22 as described above, when an arbitrary position a is set to a predetermined temperature in advance and a light pulse S is input to the optical fiber 22, the arbitrary position a is expanded to a position At the time corresponding to a1+a2+..., it is possible to obtain the intensity of backscattered light corresponding to a set temperature different from other parts as shown in Figure 14(b), so the time and intensity at this time are stored in a file. 148.

Then, the temperature signal proportional to the backscattered light obtained at the actual temperature 1111 time as shown in FIG. 14(c), for example, is sequentially sampled in synchronization with the storage time, and the sampled values are stored in the memory. After sampling in this manner, the data processing section 147 reads out the contents of the memory and averages these sampled values, thereby making it possible to detect the temperature of the measuring section 40 with high sensitivity and high resolution.

In addition, as a means for bundling the optical fibers 22 in one stroke while reciprocating in the a1 fixed area 20, for example, the 15th
It may also be carried out as shown in Figures (a), (b), and (C).

Furthermore, FIGS. 16 and 17 are diagrams showing an embodiment according to claim 5 of the present invention, in which the optical fiber 22 is used when measuring the temperature etc. of the measurement area 20 from a distance.
Since there is no need to measure from the incident end of the area to be measured 20, this j? The signal processing device 1
This is intended to reduce the burden on the memory capacity of No. 4 and improve the efficiency of data processing.

Incidentally, if the distance between each δ1 plus portion 21a, 21b, . . . is long, it may be skipped as a measurement-unnecessary portion Lng as shown in FIG.

Next, FIG. 18 is a diagram showing an embodiment according to claims 1 and 6 of the present invention. That is, in this device, controllers 41a, 41b, . . . are provided for each reference signal application means 23a, 23b, . Any group in the means 23a, 23b, . . .? It is configured to be able to apply four different temperatures.

Further, from the signal processing device 14, each controller 41a,
41b, . . . , and the intensity of the backscattered light at this time is determined as &llI. After that, the signal processing device 14 controls the controller 41 a +
If a control signal is sent to 41b+ and the reference signal applying means 23a, 23b, .
? The measuring part 2 foot part, 21b with H degree.

The temperature can be set to...

Next, in claim 7 of the present invention, in each of the above-mentioned implementation rows, the distance between some or all of the reference signal applying means 23a, 23b, .
1j, the reference signal applying means 23a.

23b, . . . to set the reference position or reference temperature,
By actually inputting the optical signal into the optical fiber 22,
The transmission time of the optical pulse within the optical fiber 22 can be determined from the optical pulse input timing signal and the time until the backscattered light from the reference position or reference temperature portion of the optical fiber 22 is received.

In this way, since different transmission times can be determined depending on the temperature and the length of the optical fiber, the temperature on the optical fiber of the optical fiber thermometer API result can be corrected using this transmission time.

Further, in each of the above embodiments, each H1 constant part, for example, 21a-
21b or fljl fixed portions 31a, 31b, .

When the reference temperature is set as a reference signal application means,
Apart from this, the reference position signal may be obtained by inserting a connecting part including welding before or after the reference signal applying means or before and after the reference signal applying means. Furthermore, 7Illll constant area 20
In the optical fiber 22, a crystal that is likely to cause Raman scattering or a crystal that is sensitive to temperature may be interposed at an appropriate location of the optical fiber 22, and these crystals may be used as reference signal applying means 23a, 23b, . ...or the connection part 2
8a.

28b, . . . may be replaced.

Further, in each of the above embodiments, the temperature is mainly constant, but the humidity can be similarly determined. For example, as shown in FIG. 19, in addition to the temperature measuring section 51 in the optical fiber 22, a humidity measuring section 52 is provided in the optical fiber 22 in the vicinity of the temperature measuring section 51, and the water 54 inside the container 53, for example, distilled water, is The humidity measuring section 52 is immersed in water 54 using capillary action caused by the cloth 55. After setting such a state, the optical pulse S is actually connected to the optical fiber 2.
2, and the temperature t of the temperature measuring section 51 and the temperature t' of the humidity measuring section 52 immersed in the water 54 are measured from the intensity of the backscattered light obtained from within the optical fiber 22 at that time. , these both temperatures t.

The relative humidity of the humidity measuring section 52 can be measured from t'.

Although distilled water is used as the water 54, ordinary tap water may be supplied manually or automatically. However, it is necessary to know in advance the error when using distilled water and tap water.

[Effects of the Invention] As explained above, the present invention provides the following various effects.

First, in claims 1 and 2, the temperature of the measurement result as well as the position of each measurement part of the measurement area is corrected from the intensity of the unique backscattered light generated from the position corresponding to the reference signal application means in the optical fiber. The temperature of a large number of measuring parts, f
It is possible to accurately measure temperature, sealing temperature, etc.

Next, in claim 3, the optical fiber is arranged in a planar or three-dimensional manner with a single stroke, and the position or temperature is predetermined on the measuring part such as all or a part of the crossing part or the non-crossing part on the optical fiber. By applying the brush signal and acquiring data, it is possible to accurately measure the temperature, humidity, etc. of a large number of C1 constant parts in a wide range of measurement areas at the actual time.

In addition, in claim 4, by reciprocating and bundling the optical fibers in the same 411 constant portion in a single stroke, the backscattered light returned from the same measurement portion at different times is averaged, thereby improving the measurement sensitivity. Resolution can be increased.

Furthermore, in claim 5, by skipping and processing portions of the optical fiber that do not require measurement, the memory capacity of the signal processing device can be reduced and the data processing speed can be increased.

Next, in claim 6, by controlling the reference temperature of the reference signal applying means so as to match the actual measurement value, the measurement value can be obtained very accurately.

Furthermore, in claim 7, the optical fiber transmission time 71'Ilj can be determined accurately.

[Brief explanation of the drawing]

1 and 2 are diagrams explaining the measurement principle of the device of the present invention, FIG. 3 is an overall configuration diagram of an embodiment of the device of the present invention, and FIG.
8 to 8 are block diagrams and measurement result diagrams related to claim 1.2, FIGS. 9 to 12 are block diagrams and timing diagrams related to claim 3, and FIGS. 13 to 15 are block diagrams and measurement result diagrams related to claim 4. 16 is a configuration diagram related to claim 5, FIG. 17 is a diagram explaining another embodiment of FIG. 16, and FIG. 18 is a configuration related to claim 6. 19 are schematic diagrams for measuring humidity. 11... Light source, 12... Beam splitter, 14.
Signal processing device, 20...Measurement area, 21a. 21b... Measuring section, 23a, 23b,... Reference signal applying means, 28a, 28b, --- Connection section, 31a. 31b...Measurement section, 40...Measurement section, 41a. 41b,...controller, 51...temperature δIII
Constant part, foot part...humidity measurement part. Figure 8.2 Patent attorney Patent attorney Takehiko Suzue Figure 9 Figure 13 Figure 14 Figure 0 (a) (b) (C) Figure 15 [- Figure 16 Figure 17

Claims (7)

[Claims] (1) Inject the optical signal from the light source to the input end of the optical fiber,
Of the Raman scattering that occurs within the optical fiber due to the incidence of this optical signal, the time it takes for the backscattered light toward the input end to return and the strength of the returned signal are analyzed by a signal processing device, and the temperature and In a measuring device for measuring humidity or temperature distribution, the measurement section of the optical fiber is continuously arranged across each measurement location in the measurement area, and
A measuring device comprising a reference signal applying means for applying a reference signal to a part or the entire area of a measuring section. (2) The reference signal may be a fixed or variable set temperature, a position reference signal from a fiber connection, etc.
2. The measuring device according to claim 1, which uses at least one temperature reference signal based on any variable known temperature. (3) Inject the optical signal from the light source to the input end of the optical fiber,
Of the Raman scattering that occurs within the optical fiber due to the incidence of this optical signal, the time it takes for the backscattered light toward the input end to return and the strength of the returned signal are analyzed by a signal processing device, and the temperature and In a measuring device for measuring humidity or temperature distribution, the optical fibers are arranged in a predetermined order in a single stroke in a two-dimensional or three-dimensional manner within the measurement area, and all or one of the crossing portions formed on the optical fibers are A predetermined reference signal is applied to an arbitrary part of the part or the non-intersecting part as a measurement part, and an optical signal is input to the input end of the optical fiber, and the backscattered light obtained by the input of the optical signal at this time and the backscattered light are sequentially obtaining and storing position data or position data and temperature data of the measuring unit from
The temperature, humidity, or temperature distribution of the measuring section is measured using the position and temperature data stored in advance during actual measurement and the backscattered light obtained by actually inputting an optical signal into the optical fiber, and the stored data is A measuring device characterized by comparing and correcting. (4) The measurement section synchronously collects backscattered light that returns from the same measurement section at different times in the signal processing device by reciprocating and bundling the optical fibers in a single stroke. 4. The measurement device according to claim 1, wherein the measurement sensitivity and resolution of the same measurement portion are increased by capturing and averaging the measurement results. (5) Inject the optical signal from the light source to the input end of the optical fiber,
A light source is used in a measuring device that uses a signal processing device to analyze and measure temperature, humidity, or temperature distribution based on backscattered light directed toward the input end of the Raman scattering generated within the optical fiber by the incidence of this optical signal. If the area from the included signal processing device to the front of the area to be measured or the part of the optical fiber excluding any area to be measured is defined as a part that does not require measurement,
During actual measurement, the signal processing device skips the measurement of the backscattered light that returns from the optical fiber portion corresponding to the measurement-unnecessary portion, and measures the backscattered light that is scattered from within the optical fiber of the part to be measured located within the measurement area. A measuring device characterized in that it measures temperature, humidity, or temperature distribution by taking in backscattered light that comes from the surrounding area. (6) Inject the optical signal from the light source to the input end of the optical fiber,
Among the Raman scattering that occurs within the optical fiber due to the incidence of this optical signal, the time taken for the backscattered light toward the input end to return and the strength of the returned signal are analyzed by a signal processing device, and the temperature and humidity are analyzed. Alternatively, in a measurement device that measures temperature distribution, the measurement section of the optical fiber is arranged continuously across each measurement location in the measurement area, and a variable reference signal is provided over a part or all of the measurement section. A reference signal applying means for applying the reference signal is provided, and the signal processing device controls the reference signal of the reference signal applying means so as to match the actual measured value of the backscattered light obtained from the optical fiber. Measuring device. (7) Inject the optical signal from the light source to the input end of the optical fiber,
Measurement in which temperature, humidity, or temperature distribution is measured by a signal processing device based on this optical signal input timing signal and backscattered light directed toward the input end of the Raman scattering generated within the optical fiber by the input of the optical signal. In the apparatus, the measurement section of the optical fiber is disposed in the region to be measured, and a reference signal applying means is provided for applying a reference signal over a part or the entire region of the measurement section, and by the incidence of the optical signal into the optical fiber, A measuring device characterized in that the transmission time of an optical signal within the optical fiber is obtained from backscattered light scattered and returned from a portion corresponding to the reference signal applying means.