JP3086674B2 - Organic substance detection device that enables finger calibration and organic substance monitoring system using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for detecting an organic substance present in a medium such as air or water, and a monitoring system using the same. The present invention relates to an organic substance detection device capable of calibrating a degree and a monitoring system using the same.

[0002]

2. Description of the Related Art The applicant of the present invention has proposed various detection devices for detecting the type and concentration of organic substances dissolved in water or vapor mixed in air. FIG. 7 schematically shows an example of such a detection device. In the figure, the detection device includes a light source unit 2, a light detection unit 4, and a sensing element 8 made of a polymer thin film coated on a flat reflective holder 6, and these components are It is held integrally by the housing 10. As the sensing element 8, a polymer having a property of reacting with a specific organic substance or absorbing or adsorbing this organic substance to change at least one of the film thickness and the refractive index is used.

A light beam emitted from a light-emitting body such as a laser diode provided in the light source unit 2 enters a sensing element 8, is reflected there, and is detected by a photodetector of a photodetecting unit 4. At this time, the light reflected on the surface of the sensing element 8 and the light reflected on the surface of the holder 6 supporting the sensing element 8 have a phase relationship and interfere with each other. When the refractive index changes, the reflectance of the sensing element or the intensity of the reflected light changes. Thus, it is possible to detect the presence and / or concentration of the fuel vapor as a function of the intensity of the reflected light from the sensing element 8.

The housing 10 has an inlet 12 for introducing air containing organic or water in which organic substances are dissolved, and an outlet 14 for discharging air or water. A passage 16 for contacting the element 8 with the organic substance is formed, and when air or water in which the organic substance is dissolved is introduced from the inlet 12, the organic substance comes into contact with the sensing element 8, Since the film thickness and the refractive index of the sensing element 8 change, it is possible to determine, as an output of the light detection unit 4, whether a specific organic substance is mixed in air or dissolved in water.

[0005] In general, the minimum detection limit (Minimum Detectable) of an organic substance detection device under a certain environment.
e Limit (MDL) is usually determined by taking the ratio of the zero level fluctuation width and the signal intensity of the organic substance detection device in the environment to one. However, if the signal intensity has a temperature-humidity characteristic, the MDL also shows the same temperature-humidity characteristic. Factors of the zero level fluctuation of the organic substance detection device include temperature and humidity characteristics of the sensing element, temperature and humidity characteristics specific to the device, electric noise specific to the device, extraneous noise (including electric noise and vibration), and the like. Can be.

In order to improve the MDL, it is possible to correct the temperature and humidity characteristics specific to the sensing element and the device using the measured temperature and humidity characteristics after the organic substance detection device is installed. However, it takes a lot of time to measure the temperature and humidity characteristics of each organic substance detection device, and this may cause a significant increase in manufacturing cost. Strictly speaking, there is a hysteresis characteristic that cannot be completely corrected by the organic substance detection device, and for such a measurement, it is necessary to operate the temperature and humidity characteristic measurement probe in the dangerous area where the organic substance detection device is installed. There is also a problem that it does not. Furthermore, the conventional organic substance detection device as shown in FIG.
Although it is configured to handle only optical signals and does not include electrical components, measurement of the temperature and humidity characteristics of such an organic substance detection device can be performed without adding any electrical element to the organic substance detection device. It is practically impossible to perform only with the optical signal.

In addition, when the conventional organic substance detecting device is installed in a place containing an organic substance (for example, a place contaminated with the organic substance) for a long time, the sensing element causes a characteristic change inherent to the organic substance detecting apparatus. There is also a drawback that the output drifts.

[0008]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to perform zero adjustment of an instrument and calibration of a finger at a monitoring center. Has a new configuration so that
An object of the present invention is to provide an organic substance detection device which is inherently safe, has a simple structure, is easy to manufacture, has high reliability, is inexpensive, and can be reduced in size. Another object of the present invention is to
An object of the present invention is to provide a monitoring system capable of performing zero point adjustment and calibration of a finger in a measurement unit using such an organic substance detection device.

[0009]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a hollow storage tube, a sensing element which causes an attribute change upon contact with an organic substance, and an optical fiber stored in the storage tube. An optical fiber for outputting light for irradiating the sensing element and receiving and transmitting light reflected by the sensing element, and disposed in the storage tube to fix an end of the optical fiber. A receptacle, a holder disposed on the storage tube so as to form a space between the receptacle and the sensing element on a surface facing the receptacle, and a medium containing the organic substance; An introduction means for introducing into the space from one end of the storage tube, and one of a medium containing no organic substance and a medium containing the organic substance having a known concentration. Providing an introduction tube for introducing from the end in the space, the organic substance detecting device, characterized by comprising, a discharge tube for evacuating the space from the other end of said housing tube. The organic substance detection device may be installed in an underground tank, a sump, a submerged pump area, an above-ground tank, a refinery, an oil feed pipe, an oil feed line, an oil feed tanker, or the like.

The organic substance detecting device is provided between the holder and the medium according to the usage mode, and preferably includes a filter that does not allow the medium to pass through but allows the organic substance in the medium to pass. In some cases, it is desirable to include a holder for mounting the sensing element so as to face the receptacle and for transmitting the medium.

According to another aspect of the present invention, there is provided a monitoring system including the above-described organic substance detecting device and a monitoring center coupled thereto, wherein the monitoring center is provided with respect to the introduction tube. A supply unit for supplying a medium containing no organic substance and a medium containing a known concentration of an organic substance for a predetermined period, and supplying light to the optical fiber; A measuring unit for processing a reflected light transmitted through the optical fiber and outputting a signal indicating one of the presence and the concentration of the organic substance, and the supply unit with respect to the introduction tube, Adjusting the zero point of the measurement unit when supplying a medium containing no organic substance, and calibrating the index of the measurement unit when supplying a medium containing a known concentration of organic substance. Monitoring system for the ability to provide.

In this monitoring system, the measuring unit is connected to the other end of the optical fiber and transmits a laser beam to the optical fiber, and detects a laser beam reflected from the sensing element. And a detection converter for outputting an electric signal corresponding to the intensity of the laser light.

The supply unit includes a first cylinder containing a dry inorganic gas, a second cylinder containing air containing a known concentration of an organic gas, the first cylinder and the second cylinder. When it is desirable to provide a valve means for coupling any one of the organic substance detection device and the first substance containing water in which the organic substance is not dissolved, and a known concentration of the organic substance It may be desirable to have a second cylinder containing dissolved water and valve means for coupling one of the first and second cylinders to the organic substance detection device. .

[0014]

The attribute of the sensing element, for example, the film thickness or the refractive index changes due to the contact of the organic substance. By using this,
Detect the presence or concentration of organic substances. That is, as a result of the interaction with the organic substance, a physical change such as swelling occurs in the sensing element. Further, due to such swelling, the film thickness and the refractive index, which are optical parameters of the sensing element, change. Since such a change changes the optical properties of the sensing element, an organic substance can be detected by measuring the reflection properties of the sensing element.

By appropriately selecting the polymer material constituting the sensing element, it is possible to selectively or non-selectively detect the presence of an organic substance, for example, a fuel such as gasoline, light oil, kerosene, jet fuel, or heavy oil. It becomes possible. In addition, since the sensing element has a reflection characteristic corresponding to the concentration of the organic substance, the organic substance detecting device according to the present invention can also operate as an organic substance concentration meter.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Some embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows the configuration of a first embodiment of an organic substance detection device according to the present invention, which is for detecting an organic substance mixed in air.

In the organic substance detection device 20 shown in FIG. 1, one end of the optical fiber 22 having one end connected to the measurement / control unit 62 (FIG. 2) of the monitoring center 60 is connected to the receptacle 26 having a collimator lens via the FC connector 24. Fixed to A sensing element 30 fixed to the sensing element holder 28 with an adhesive or the like is arranged so as to face the collimator lens in the receptacle 26. The light emitted from the measurement / control unit 62 and transmitted by the optical fiber 22 is transmitted through the collimator lens in the receptacle 26 to the sensing element 30.
Irradiates the optical fiber 22
, And returns to the measurement / control section 62.

The receptacle 26 is fixed to one end of a cylindrical main body 32, and a sensing element holder 28 is fixed inside the main body 32. An O-ring 34 is provided in the opening at the other end of the main body 32 to prevent water or the like from entering from the outside. The O-ring 34 is fixed to an O-ring holder 36.

A lid 40 having a filter 38 inside is fixed to the outer periphery of the other end of the main body 32. An opening 42 is provided at the center of the lid 40, and the filter 38 is in contact with the outside air through the opening 42, and has a property of not allowing water to pass therethrough but allowing organic substances dissolved in the water to pass therethrough. An O-ring 44 in contact with the O-ring holder 34 is also provided at one end of the lid 40, and the filter 38 is fixed to the lid 40 by being sandwiched between the O-ring 44 and a gasket and a support screen (neither is shown). You. At least one vent hole 48 is formed in the sensing element holder 28 so that the sensing element 30 contacts the filter 38 and the outside air passing through the vent hole 48.

The outer peripheries of the FC connector 24, the receptacle 26, and the main body 32 are covered with a cylinder 46 made of a material such as stainless steel to prevent water or the like from entering. Further, the detecting unit 2
0, which penetrates through the cylinder 46 and is connected at one end to one of the cylinders in the monitoring center 60;
An exhaust tube 52 having one end connected to the exhaust treatment device is provided. The other end of the introduction tube 50 is air-tightly connected to one end of an introduction path 54 formed in the main body 32, and
The other end of 4 opens into a chamber 56 which is a space between the sensing element 30 and the receptacle 26. Similarly, the other end of the discharge tube 52 is connected to the discharge passage 5 formed in the main body 32.
8 is airtightly connected to one end, and the other end of the discharge path 58 also opens to the chamber 56. The introduction tube 50 and the discharge tube 52 are connected to the main body 32 such that the other ends of the introduction tube 50 and the discharge tube 52 communicate with the chamber 56.
May be penetrated.

In the present invention, for example, the IER method is used to detect the attribute of the sensing element 30 by utilizing the property that the attribute of the sensing element 30, for example, the film thickness or the refractive index changes upon contact with an organic substance. . The IER method utilizes the optical interference characteristics of a thin film structure. The light reflected on the surface of the sensing element 30 has a phase relationship with the light reflected from the interface between the sensing element and the reflective surface of the holder and interferes with each other. The reflectivity of the sensing element 30 largely depends on the thickness and / or the refractive index of the sensing element. That is, the sensing element 30
When the film thickness and / or the refractive index of the sensor 30 change, the reflectivity of the sensing element 30 or the intensity of light reflected therefrom changes. Thus, the IER method makes it possible to detect the presence and / or concentration of organic substances as a function of the intensity of the reflected light.

As described above, the IER method is sensitive to a change in the film thickness.
If a material having a refractive index not so different from that of the organic substance is used as 0, in the present invention, the influence of the thickness of the sensing element 30 may be more important than the refractive index. . This is a unique advantage of the present invention over the prior art.

It is known that the reflectance of the sensing element 30 suitable for the IER method changes sinusoidally with an increase in the concentration of the organic substance. Therefore, it is necessary to adjust the reflectance as follows according to the concentration range of the organic substance. preferable. First, when the concentration of the organic substance is low, the change in the reflectance of the sensing element 30 is small. Therefore, when the film thickness is adjusted to the minimum value or the maximum value of the reflectance, a sufficient change in the reflectance occurs. I can't get it. Therefore, λ / corresponding to the minimum value and the maximum value of the reflectivity
It is desirable that the value is not close to a multiple of 4 ncos θ (where λ is the wavelength of the incident light, n is the refractive index of the sensing element 30, and θ is the light propagation angle in the sensing element 30). on the other hand,
When the concentration of the organic substance is relatively high, the change in the reflectance of the sensing element 30 is large. Therefore, in order to increase the signal span, it is preferable to adjust the film thickness to correspond to the minimum value or the maximum value of the reflectance. The thickness of the sensing element 30 is 10 nm to 10 μm
m, but is preferably less than 1 μm for high-speed response.

The sensing element 30 is

[0025]

Embedded image

It is preferably a homopolymer or a copolymer having a repeating unit represented by the following formula: here,
X is, -H, -F, -Cl, -Br , -CH 3, -C
Represents F ₃ , —CN or —CH ₂ —CH ₃ , wherein R ¹ is —R ²
Or represents -Z-R ^2, Z is, -O -, - S -, - NH
-, -NR ² '-,-(C = Y)-,-(C = Y) -Y
-, - Y- (C = Y ) -, - (SO 2) -, - Y'-
(SO ₂ )-,-(SO ₂ ) -Y'-, -Y '-(S
_{O 2) -Y '-, -} NH- (C = O) -, - (C = O)
-NH-,-(C = O) -NR ² '-, -Y'-(C =
Y) -Y'- or -O- (C = O) - ( CH 2) n - (C
＝ O) -O-, Y independently represents O or S;
Y 'represents O or NH, independently, n represents an integer of 0 to 20, R ² and R ^2' are independently hydrogen, straight chain alkyl groups, branched-chain alkyl group, a cycloalkyl group, unsaturated Represents a saturated hydrocarbon group, an aryl group, a saturated or unsaturated heterocyclic ring, or a derivative thereof. However, R ¹ is not hydrogen, a linear alkyl group or a branched alkyl group.

Preferably, X in the above-mentioned repeating unit (I)
Represents H or CH _3, R ¹ represents a substituted or unsubstituted aryl group or -Z-R ^2, Z is, -O -, - (C =
O) represents —O— or —O— (C ＝ O) —, and R ² represents a linear alkyl group, a branched alkyl group, a cycloalkyl group, an unsaturated hydrocarbon group, an aryl group, a saturated or unsaturated heterocyclic ring Or a derivative thereof.

The polymer used as the sensing element may be a polymer consisting of a single repeating unit (I) or a copolymer consisting of another repeating unit and the above repeating unit (I), Copolymers of two or more types of (I) may be used. The arrangement of the repeating units in the copolymer may be any, for example, a random copolymer, an alternating copolymer, a block copolymer or a graft copolymer can be used. In particular, the sensing elements are polymethacrylates,
It is particularly preferred that they are prepared from polyacrylates. The side chain group of the ester is preferably a linear or branched alkyl group or a cycloalkyl group, and preferably has 4 to 22 carbon atoms.

Particularly preferred polymers for use in sensing element 30 are listed below: poly (dodecyl methacrylate) poly (isodecyl methacrylate) poly (2-ethylhexyl methacrylate) poly (2-ethylhexyl methacrylate-co-methacryl) (Methyl methacrylate) poly (2-ethylhexyl methacrylate-co-styrene) poly (methyl methacrylate-co-2-ethylhexyl acrylate) poly (methyl methacrylate-co-2-ethylhexyl methacrylate) poly (isobutyl methacrylate-co) -Glycidyl methacrylate) poly (cyclohexyl methacrylate) poly (octadecyl methacrylate) poly (octadecyl methacrylate-co-styrene) poly (vinyl propionate) poly (dodecyl methacrylate-co-styrene) Poly (butyl methacrylate-co-glycidyl methacrylate) Poly (butyl methacrylate) Poly (butyl methacrylate-co-methyl methacrylate) Poly (butyl methacrylate-co-glycidyl methacrylate) Poly (2-ethylhexyl methacrylate) co-glycidyl methacrylate poly (cyclohexyl methacrylate-co-glycidyl methacrylate) poly (cyclohexyl methacrylate-co-methyl methacrylate) poly (benzyl methacrylate-co-methacrylic acid 2-)
Ethylhexyl Poly (2-ethylhexyl methacrylate-co-diacetone acrylamide) Poly (2-ethylhexyl methacrylate-co-benzyl-methacrylate-co-glycidyl methacrylate) Poly (2-ethylhexyl methacrylate-co-methyl methacrylate) co-glycidyl methacrylate poly (vinyl cinnamate) poly (vinyl cinnamate-co-dodecyl methacrylate) poly (tetrahydrofurfuryl methacrylate) poly (hexadecyl methacrylate) poly (2-ethylbutyl methacrylate) poly (methacrylic acid) 2-hydroxyethyl) poly (cyclohexyl methacrylate-co-isobutyl methacrylate) poly (cyclohexyl methacrylate-co-2-ethylhexyl methacrylate) poly (butyl methacrylate-c) -2-ethylhexyl methacrylate) poly (butyl methacrylate-co-isobutyl methacrylate) poly (cyclohexyl methacrylate-co-butyl methacrylate) poly (cyclohexyl methacrylate-co-dodecyl methacrylate) poly (butyl methacrylate-co -Ethyl methacrylate) Poly (butyl methacrylate-co-octadecyl methacrylate) Poly (butyl methacrylate-co-styrene) Poly (4-methylstyrene) Poly (cyclohexyl methacrylate-co-benzyl methacrylate) Poly (methacrylic acid) Dodecyl-co-benzyl methacrylate poly (octadecyl methacrylate-co-benzyl methacrylate) poly (benzyl methacrylate-co-tetrahydrofurfuryl methacrylate) poly (methacrylic acid) Poly (hexyldecyl-co-hexadecyl methacrylate) poly (dodecyl methacrylate-co-methyl methacrylate) poly (dodecyl methacrylate-co-ethyl methacrylate) poly (2-ethylhexyl methacrylate-co-dodecyl methacrylate) poly (methacrylic acid) 2-ethylhexyl-co-octadecyl methacrylate) poly (2-ethylbutyl methacrylate-co-benzyl methacrylate)) poly (tetrahydrofurfuryl methacrylate-co-glycidyl methacrylate) poly (styrene-co-octadecyl acrylate) poly (Octadecyl methacrylate-co-glycidyl methacrylate) poly (4-methoxystyrene) poly (2-ethylbutyl methacrylate-co-glycidyl methacrylate) poly (styrene-co-methacrylic acid) Tiger tetrahydrofurfuryl) poly (2-ethylhexyl methacrylate--co- propyl methacrylate) poly (octadecyl methacrylate -co- methacrylate isopropyl) poly (3-methyl-4-hydroxystyrene -co-4
-Hydroxystyrene) Poly (styrene-co-2-ethylhexyl methacrylate-co-glycidyl methacrylate).

In the methacrylic ester polymer or copolymer, acrylic acid may be used instead of methacrylic acid. The above polymer can be crosslinked by itself, but can be crosslinked by introducing a compound having a reactive group for crosslinking into the polymer. Examples of such a crosslinking reactive group include, for example, an amino group, a hydroxyl group, a carboxyl group, an epoxy group, a carbonyl group, a urethane group and derivatives thereof, and maleic acid, fumaric acid, sorbic acid,
Mention may be made of itaconic acid and cinnamic acid and their derivatives. Substances having a chemical structure capable of forming carbene or nitrene upon irradiation with visible light, ultraviolet light, or high-energy radiation can also be used as the crosslinking agent. Since the film formed from the crosslinked polymer is insoluble, the stability of the detector can be increased by crosslinking the polymer forming the polymer thin film 4. The crosslinking method is not particularly limited, and a conventionally known crosslinking method, for example, a method by heating or a method by irradiation with light or radiation can be used.

In the organic substance detecting device of FIG. 1, the surface of the sensing element holder 28 supporting the sensing element 30 is preferably sufficiently flat to reflect light, and the sensing element holder 28 itself has a high reflectance. It may be something. An example of the sensing element holder 28 is a silicon wafer. The sensing element 30 is provided by a spin coating method or another commonly used coating method.
8 is preferably formed on the surface. In order to actually produce the sensing element 30, 8.5 g of poly (benzyl methacrylate-co-2-ethylhexyl methacrylate) was dissolved in cyclohexanone to make a total amount of 100 g, and the solution was spun on a substrate made of a silicon wafer at 2900 rpm. Coat and
A polymer thin film was formed. After drying under reduced pressure at 60 ° C. for 1 hour, the thickness of the polymer thin film was measured using a three-wavelength automatic ellipsometer “Auto EL IV NIR” manufactured by Rudol Research.
III ", it was about 330 nm.
The substrate made of the silicon wafer was cut into a 10 mm × 10 mm square to form a sensing element 30.

The filter 38 shown in FIG. 1 does not allow water to pass through only organic substances in the air, but selectively removes organic substances dissolved or separated in water in water.
Has the property of being able to take in only organic substances as vapor except water, for example, polymer separation membranes, that is, polyethylene, polypropylene, polystyrene, polycarbonate, polyphenylene oxide, polyphenylene ether, polyphenylene sulfide, polyether sulfone, polyether Ether ketone, polyetherimide, polysulfone, polyethylene naphthalate, polyacetal, polybutylene terephthalate, fluororesin,
Polyparabanic acid resin, wholly aromatic polyamide, polythiol, amino alkyd resin, acrylic resin, polycellulose, natural rubber, polyester, unsaturated polyester, epoxy resin, silicone resin, and derivatives thereof, and these It is preferable to use a separation membrane made of a polymer laminate, a ceramic, a porous metal, and a separation membrane made of these laminates.

Preferred among these are hydrophobic PTFs.
E (polytetrafluoroethylene) membrane, hydrophobic PVD
An F (polyvinylidene fluoride) film, a hydrophobic polyethylene film, a hydrophobic polypropylene film, a hydrophobic polyethylene-PTFE laminated film, and a hydrophobic polypropylene-polyethylene-polypropylene laminated film.

Preferably, a separation membrane having a diameter of 0.01 to 100 μm and a thickness of 50 to 2000 μm, particularly preferably a separation membrane having a diameter of 0.05 to 20 μm and a thickness of 70 to 300 μm is used. Specifically, a hydrophobic PTFE membrane:
(0.1-70), (0.2-80), (0.5-7)
5), (1-75), (3-75), (5-125),
(10-125), hydrophobic polypropylene net support PTFE membrane: (0.1-130), (0.2-13)
0), (0.5-120), (0.2-175),
(0.5-175), (1-145), (3-20)
0), hydrophobic polyvinylidene fluoride membrane: (0.1
-125), (0.22-125), (0.45-12)
5), (0.65-125) and (5-125).
The above () indicates the combination of the pore diameter and the thickness of each material, and the unit is micron.

Next, FIG. 2 shows one embodiment of a monitoring center 60 according to the present invention, which is combined with the organic substance detection device of FIG. 1 to constitute a monitoring system. FIG.
, One end of the optical fiber 22 is
One end of the introduction tube 50 is connected to the switching valve 64, and one end of the discharge tube 52 is connected to the exhaust treatment device 66. The gas processed by the exhaust processing device 66 is discharged to the outside air via a tube 68. If necessary, air filters 70 and 72 may be provided at appropriate places between the introduction tube 50 and the discharge tube 52. Further, the optical fiber 22, the introduction tube 50 and the discharge tube 5
For protection of 2, it is desirable to store these in a tube made of, for example, Teflon or stainless steel (indicated by a dashed line).

The measurement / control section 62 receives the light source connected to the end of the optical fiber 22 and the reflected light reflected by the sensing element 30 and transmitted through the optical fiber 22, and is proportional to the intensity of the reflected light. It includes a light detection circuit for generating an electric signal, an instrument for displaying the magnitude of the electric signal, and a control circuit for controlling the switching valve 64 to operate at the timing shown in FIG. Laser diodes or light-emitting diodes are suitable as light sources.

The switching valve 64 is connected to a first cylinder 74 in which a first gas is compressed and stored, and a second cylinder 76 in which a second gas different from the first gas is compressed and stored. You. The switching valve 64 connects the introduction tube 48 to the first cylinder 7 according to a control signal 78 from the measurement / control unit 62.
The connection is switched to the fourth or second cylinder 76.

The first gas is used for adjusting the zero point of the instrument in the measurement / control section 62, and is a gas containing no organic substance, such as dry air, dry nitrogen, dry argon, etc. Is most preferred. During the period when the introduction tube 50 is connected to the first cylinder 74 by the switching valve 64, for example, dry air is supplied from the first cylinder 74 to the detection unit 20 through the introduction tube 50, and the discharge tube 5 is discharged.
Since the air is exhausted through the sensor 2, it is possible to adjust the instrument in the measurement / control unit 62 to indicate zero using the intensity of the reflected light from the sensing element 30 at this time.

The second gas is used to calibrate the indicator of the instrument in the measurement / control unit 62, and a dry organic gas such as dry isobutane or dry propane having a known concentration is used.
For example, when the detection unit 20 is installed at a gas station and a leak of oil is to be detected, the second gas is 50 to 8,000 ppm, which is smaller than the explosion lower limit of 8,500 ppm.
, Preferably 100 ppm of dry isobutane. Assuming that dry isobutane having a concentration of 100 ppm is sent to the chamber 56 through the introduction tube 50, the measurement / control unit 6 utilizes the intensity of the reflected light from the sensing element 30 that has absorbed or adsorbed this isobutane.
The instrument in 2 can be calibrated to indicate the presence of 100 ppm isobutane.

FIG. 3 shows that the switching valve 64 is connected to the introduction tube 5.
FIG. 3A shows the relationship between the timing at which 0 is connected to the first cylinder 74 or the second cylinder 76 and the calibration period of the instrument of the measurement / control section 62. FIG. 3B shows that the introduction tube 50 is connected to the second cylinder 76 from time t2 to time t3. The measurement / control unit 62 includes a switching valve 64
Control signal 78, and the switching valve 64 operates 1 to 10 per day.
The introduction tube 50 is controlled to be connected to the first cylinder 74 and the second cylinder 76 alternately and periodically, preferably eight times. FIG. 3 shows that the introduction tube 50 is connected to the first cylinder 74 or the second cylinder 76 once each time, but the operation from time t1 to time t3 is performed several times each time. It may be repeated.

The period during which the introduction tube 50 is connected to the first cylinder 74 or the second cylinder 76 (the periods t1 to t2 and t2 to t3 in FIG. 3) is between the detection unit 20 and the monitoring center 60. It is good to set according to the distance, and is usually 30 seconds to 60 minutes.

The apparatus shown in FIG. 4 can be used instead of the first cylinder 74. In FIG. 4, air sent from an air compressor 80 such as a reciprocating air compressor or a screw air compressor is dried by an air dryer (for example, a refrigeration air dryer) 82 and temporarily stored in an air tank 84. Dry air from the air tank 84 is supplied to the first mist separator 8.
6. Fine mist is removed by the second mist separator 88 and supplied to the switching valve 64 via the oil odor filter 90. If a compressed air source can be used, the compressed air may be supplied to the switching valve 64 via a mist separator or an oil odor filter.

Next, a second embodiment of the organic substance detection apparatus according to the present invention and a monitoring system using the same will be described with reference to FIGS. The organic substance detection device in this embodiment is for detecting an organic substance mixed in water. The same or similar components as those in the first embodiment shown in FIGS. 1 and 2 are denoted by the same reference numerals, and description thereof will be omitted.

FIG. 5 shows the structure of an organic substance detecting device according to a second embodiment of the present invention. In the organic substance detecting device 20 'shown in FIG. 5, a receptacle 26 having a collimator lens is fixed to one side of a cylindrical main body 32, and a sensing element is provided on the other side of the main body 32 so as to face the collimator lens. 30 are arranged. The sensing element 30 is fixed to the sensing element holder 92 with an adhesive or the like. The sensing element holder 92 is made of a water-permeable material such as a sintered metal, and is hermetically attached to the main body 32. A space between the sensing element 30 and the receptacle 26, that is, the chamber 56 communicates with the introduction tube 50 and the discharge tube 52.

FIG. 6 shows a second embodiment of the monitoring center according to the present invention, which is connected to the organic substance detecting device 20 'of FIG. The monitoring center 60 'shown in FIG. 6 includes a first tank 94 storing a first fluid and a second tank 96 storing a second fluid different from the first fluid. The switching valve 64 to which one end of the introduction tube 50 is connected is connected to a first tank 94 via a filter 98 and a pump 100, and is connected to a second tank 96 via another filter 102 and a pump 104. Connected.
As in the first embodiment, the switching valve 64
Is connected to the first tank 94 or the second tank 9 by the control signal 78 from the measurement / control unit 62.
6 to be connected. One end of the discharge tube 52 is connected to the waste liquid treatment device 106,
The water treated at 06 is discharged through the tube 108.

The first fluid is used for adjusting the zero point of an instrument in the measurement / control section 62, and is city water, well water, pure water, etc., and pure water is particularly preferred. The second fluid is used for calibrating the finger of a meter in the measurement / control unit 62 and contains a known concentration of an organic substance. As the second fluid, 1-2
Water containing 00 ppm of organic substances, such as water containing 10 ppm of toluene or 10 ppm of xylene, is preferred. For example, 10
When water containing ppm of toluene is supplied to the chamber 56, the intensity of the reflected light from the sensing element 30 which has absorbed or adsorbed the toluene is used to measure the presence of 10 ppm of toluene in the measurement / control unit 62. Can be calibrated to indicate.

In the monitoring center 60 'of FIG. 6, the measurement / control section 62 operates the switching valve 64 at the same timing as shown in FIG. 3 to move the introduction tube 50 to the first cylinder 74 or the second cylinder 76. Are connected alternately.

In the first and second embodiments described above, both the zero adjustment of the instrument in the measurement / control section 62 and the calibration of the finger are performed. If it is sufficient to perform only the operation, a valve is simply installed instead of the switching valve 64, and this valve is controlled by the measurement / control unit 62 to adjust the introduction tube 50 at a predetermined timing at the zero point. First cylinder 74 or first tank 94
In the case of calibration of the finger strength, it may be connected to the second cylinder 76 or the second tank 96.

[0049]

As described above, the embodiments of the present invention have been described in detail with reference to the drawings.
The present invention relates to a temperature fluctuation at a place where a detecting unit is installed,
Calibration of the instrument's zero point and finger strength without being affected by various fluctuation factors such as fluctuations in the refractive index due to aging of the sensing element enables highly accurate detection of the presence and concentration of organic substances. It has a special effect that it becomes possible to

[Brief description of the drawings]

FIG. 1 is a diagram schematically showing a configuration of a first embodiment of an organic substance detection device according to the present invention.

FIG. 2 is a diagram schematically showing a configuration of a first embodiment of a monitoring center according to the present invention, which is connected to the organic substance detection device of FIG. 1;

3 (A) and (B) show operation timings of the switching valve of FIG. 2, and FIG. 3 (C) is a graph showing a period during which zero-point adjustment of a meter and calibration of a finger are performed.

FIG. 4 is a diagram schematically showing a configuration of an apparatus that can be used instead of the first cylinder shown in FIG. 2;

FIG. 5 is a diagram schematically showing a configuration of an organic substance detection device according to a second embodiment of the present invention.

FIG. 6 is a diagram schematically showing a configuration of a monitoring center according to a second embodiment of the present invention, which is connected to the organic substance detection device of FIG. 5;

FIG. 7 is a diagram showing a configuration of a conventional organic substance detection device.

[Explanation of symbols]

20, 20 ': organic substance detection device, 22: optical fiber, 24: FC connector, 26: receptacle, 3
0: sensing element, 32: body, 38: filter, 5
0: introduction tube, 52: discharge tube, 54: introduction path, 56: chamber, 58: discharge path, 60, 6
0 ': monitoring center, 62: measurement / control unit, 64: switching valve, 66: exhaust treatment device, 70, 72: filter, 74, 76: cylinder, 92: sensing element holder, 94, 96: tank

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor James B. Stamatoff 1-3-2 Minamidai, Kawagoe-shi, Saitama Prefecture Hoechst Research and Technology Co., Ltd. (72) Hironobu Yamamoto 1-3-Minamidai, Kawagoe-shi, Saitama Prefecture 2 In Hoechst Research and Technology Co., Ltd. (72) Inventor Akihiro Takaya 1-3-2, Minamidai, Kawagoe-shi, Saitama Prefecture In Hoechst Research and Technology Co., Ltd. (56) References JP-A-8-184560 (JP, A) JP-A-1-148944 (JP, A) JP-A-6-222006 (JP, A) JP-A-4-102047 (JP, A) JP-A-7-72081 (JP, A) JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01N 21/00-21/65 G01B 11/06

Claims (7)

(57) [Claims] 1. A hollow storage tube, a sensing element that causes an attribute change when it comes into contact with an organic substance, and an optical fiber housed in the storage tube, which outputs light for irradiating the sensing element and performs the sensing. An optical fiber for receiving and transmitting the light reflected by the element; a receptacle disposed in the storage tube so as to fix an end of the optical fiber; and mounting the sensing element on a surface facing the receptacle. A holder disposed in the storage tube so as to form a space between the receptacle and the container; an introduction unit for introducing a medium containing the organic substance into the space from one end of the storage tube; An introduction tube for introducing one of a medium containing no and a medium containing a known concentration of the organic substance into the space from the other end of the storage tube; The organic substance detecting device characterized by comprising a, a discharge tube for evacuating the space from the other end of said housing tube. 2. The receptacle further comprising a lens to which one end of the optical fiber is coupled to focus light from the optical fiber to the sensing element and transmit light reflected from the sensing element to the optical fiber. The organic substance detection device according to claim 1, wherein: 3. The introduction means is provided on the opposite side of the holder with respect to the receptacle, and is provided with a filter for passing only the organic substance, and a holder for introducing the organic medium passing through the filter into the space. The organic substance detection device according to claim 1, further comprising: a formed vent. 4. The organic substance detecting device according to claim 1, wherein said holder also serves as said introducing means. 5. A monitor comprising: the organic substance detection device according to claim 1; and a monitoring center to which ends of the optical fiber, the introduction tube, and the exhaust tube are coupled. In the system, the monitoring center supplies, to the introduction tube, one of a medium containing no organic substance and a medium containing a known concentration of the organic substance for a predetermined period. A supply unit for supplying light to the optical fiber, processing reflected light transmitted through the optical fiber, and outputting a signal indicating one of the presence and concentration of the organic substance. A measuring unit, which comprises: from the supply unit to the introduction tube,
Adjusting the zero point of the measurement unit when supplying a medium that does not contain the organic substance, and performing calibration of the measurement unit when supplying a medium that contains the organic substance with a known concentration. Characteristic monitoring system. 6. The apparatus according to claim 1, wherein the organic substance detection device is arranged so as to be in contact with the outside air, and the supply unit includes a first cylinder containing a dry inorganic gas, and a second cylinder containing air containing a known concentration of an organic gas. The monitoring according to claim 5, further comprising: a cylinder for connecting one of the first cylinder and the second cylinder to the organic substance detection device. system. 7. The organic substance detection device is disposed in water, and the supply unit accommodates a first cylinder containing water in which the organic substance is not dissolved, and a water in which a known concentration of the organic substance is dissolved. And a valve means for connecting any one of the first cylinder and the second cylinder to the organic substance detection device. The described monitoring system.