TWI410664B - Optical oil detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical oil detector capable of maintaining its proper detection characteristic over a long period of time even if algae is attached to the outer circumferential surface of an optical fiber. <P>SOLUTION: The optical oil detector detects oil by using detection light which is made incident to the optical fiber from a light projecting section wherein light having a wavelength which suppresses the growth potential of the algae is employed as the detection light. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

Optical oil detector

The present invention relates to an optical oil detector that uses detection light to detect oil. The present application claims priority based on Japanese Patent Application No. 2008-228568, filed on Sep. 5, 2008, the entire disclosure of which is incorporated herein.

Conventionally, there has been known an optical oil detector that detects the presence or absence of oil in water by using detection light incident on a light projecting portion of an optical fiber.

Here, Japanese Patent Application No. 4008910 (page 9, FIG. 1) discloses an optical oil detector comprising: a floating body floating near a water surface; an optical fiber provided in the floating body; and detecting light a light projecting portion that enters one end of the optical fiber; and a light receiving portion that converts the detection light emitted from the other end of the optical fiber into an electrical signal.

First, the fiber is immersed in water under normal use. Further, since the refractive index of water is smaller than the refractive index of the outer peripheral portion of the optical fiber, the detection light system passes through the optical fiber while reflecting on the outer peripheral surface of the optical fiber.

On the other hand, when the oil adheres to the outer peripheral surface of the optical fiber, since the refractive index of the oil is larger than the refractive index of the outer peripheral portion of the optical fiber, the detection light that is reflected and passed through the optical fiber is refracted at the portion where the oil adheres, and At least a portion of the detected light leaks from the outer peripheral surface to the outside of the optical fiber. When the light leakage is detected, since the amount of light emitted from the other end of the optical fiber is reduced, the optical oil detector detects the presence or absence of oil in the water by grasping the decrease in the amount of light of the detection light.

However, since the detector disclosed in the above patent document is used in water, the algae adheres to the outer peripheral surface of the optical fiber when used for a certain period of time. However, since the algae retains water around its periphery, even if the algae adhere to the outer surface of the optical fiber, if it is carefully observed, the water will substantially contact the outer peripheral surface of the optical fiber. Therefore, even if the algae adheres to the outer surface of the optical fiber, the detection light is only slightly leaked, and it is difficult for the optical oil detector to grasp the leakage.

Further, the algae adhering to the outer peripheral surface of the optical fiber hinders the adhesion of the oil to the outer peripheral surface of the optical fiber. Therefore, there is a problem that the optical oil detector cannot detect the presence or absence of oil in the water due to the adhesion of the algae to the outer peripheral surface of the optical fiber.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an optical oil detector which can maintain normal detection characteristics for a long period of time even when algae adhere to the outer surface of an optical fiber.

In order to solve the above problems, the present invention employs the following means.

The optical oil detector of the present invention uses an optical oil detector that detects oil from detection light incident on a light projecting portion of an optical fiber, and uses the detection light as light having a wavelength of growth resistance of algae.

In the optical oil detector of the present invention having the above-described configuration, when the algae floating in the water adheres to the outer peripheral surface of the optical fiber, the optical fiber is leaked minutely from the outer peripheral surface even in the normal use state. The algae is irradiated with light having a wavelength of growth resistance of algae. As a result, in the optical oil detector of the present invention, the growth of algae in the outer peripheral surface of the optical fiber can be suppressed.

Further, in the optical oil detector of the present invention, it is preferable that the detection light system is ultraviolet light.

In the optical oil detector of the present invention having the above-described configuration, the algae adhering to the outer surface of the optical fiber is irradiated with the ultraviolet light having the growth resistance of the algae, so that the growth of the algae in the outer peripheral surface of the optical fiber can be suppressed.

Further, in the optical oil detector of the present invention, the wavelength of the ultraviolet light is preferably from 200 nm to 280 nm.

In the optical oil detector of the present invention having the above-described configuration, since the ultraviolet light having a wavelength of 200 nm to 280 nm has a property of destroying living organisms, algae adhering to the outer peripheral surface of the optical fiber can be eliminated, and the outer periphery of the optical fiber can be suppressed. The growth of algae in the face.

Further, in the optical oil detector of the present invention, the wavelength of the ultraviolet light is preferably 280 nm to 400 nm.

In the optical oil detector of the present invention having the above-described configuration, since the ultraviolet light having a wavelength of 200 nm to 400 nm has the growth resistance of algae, the growth of algae in the outer peripheral surface of the optical fiber can be suppressed.

Preferably, the optical oil detector of the present invention has a second light projecting portion that allows the second detection light having a wavelength different from the wavelength of the detection light emitted from the light projecting portion to enter the optical fiber; and the switching portion, the selectivity The light projection from the light projecting unit and the second light projecting unit is switched.

In the optical oil detector of the present invention having the above-described configuration, the presence or absence of oil in the water can be detected by the second detection light while the second detection light is incident on the optical fiber by the second light projecting portion. Further, during the period in which the detection light is incident on the optical fiber by the light projecting portion, the formation of algae in the outer peripheral surface of the optical fiber can be suppressed. long.

Further, in the optical oil detector of the present invention, the second detection light is preferably visible light.

In the optical oil detector of the present invention having the above-described configuration, the presence or absence of oil in the water can be detected by visible light while the visible light is incident on the optical fiber by the second light projecting portion.

Further, in the optical oil detector of the present invention, it is preferable that the optical fiber is provided in the floating body.

Since the refractive index of water and air is different, when the ratio of the portion of the optical fiber that is in contact with water to the portion that is in contact with air changes, the amount of light leakage from the optical fiber also changes. Therefore, when the above ratio is changed, there is a possibility that the optical oil detector malfunctions.

In the optical oil detector of the present invention, since the floating system floats near the water surface, the optical fiber is maintained at a substantially constant position from the water surface. As a result, since the amount of light leakage from the optical fiber is substantially constant, malfunction of the detector can be prevented.

(First embodiment)

The overall configuration of the optical oil detector 1 of the present embodiment will be described with reference to Figs. 1A and 1B.

1A and 1B are schematic views showing an overall configuration of an optical oil detector 1 according to a first embodiment of the present invention. Fig. 1A is a plan view of an optical oil detector 1, and Fig. 1B is an optical oil detector. 1 and the side view of the drainage pit (pit) P.

The optical oil detector 1 is a detector for detecting the presence or absence of oil mixed in the water stored in the drain pit P. The optical oil detector 1 includes a floating body 2 that floats near a water surface of water stored in the drainage pit P, a monitor 3 that is disposed in the vicinity of the drainage pit P, and an elongated rod-shaped member that allows the floating body 2 to be a rod 4 connected to the side wall of the drain pit P; and a cable 5 for electrically connecting the rod 4 and the monitor 3.

The floating body 2 has a detecting unit 30 for detecting the presence or absence of oil in the water (see Fig. 5). The details will be described later.

The monitor 3 is a machine that inputs a signal related to oil detection output from the floating body 2 to generate an alarm signal or the like. In addition, the monitor 3 can also be connected to a computer for data collection and the like.

Both ends of the rod 4 are connected to the floating body 2 and the side wall bracket 41 provided on the side wall of the drain pit P, respectively.

Further, the rod 4 is rotatably provided at its both end portions in a direction orthogonal to the extending direction of the rod and extending in the direction of the horizontal plane.

The cable 5 is detachably connected to the floating body 2, and is a cable for supplying electric power to the floating body 2 and transmitting an oil detection signal output from the floating body 2 to the monitor 3. Furthermore, the cable 5 is laid along the rod 4.

Next, the configuration of the floating body 2 of the present embodiment will be described with reference to Figs. 2 to 4 .

Fig. 2 is a perspective view showing the configuration of the floating body 2 according to the first embodiment of the present invention. Figure 3 is a cross-sectional view of the floating body 2. Fig. 4 is a sectional view taken along line A-A of Fig. 3.

The floating body 2 is provided with a tree having an internal space sealed in a waterproof state. A grease case 10; a substrate 20 provided at a central portion in the casing 10; and a detecting portion 30 provided in the casing 10 and detecting the presence or absence of oil in the water.

The casing 10 has a main body portion 11 , a lid portion 12 that covers the upper portion of the main body portion 11 in a waterproof state, a cover portion 13 that is provided on the lid portion 12 and covers a connector to be described later, and a side that is provided on the side of the main body portion 11 . a guide portion 14; a second guide portion 15 provided at the bottom of the main body portion 11; and a ballast 16 fixed to the lower end portion of the main body portion 11 by bolts. Further, the main body portion 11 is formed into a substantially cylindrical shape having a bottom which becomes thinner as it goes downward, and a lower spherical end is formed in a substantially spherical curved surface. In addition, the housing 10 has buoyancy that floats as far as possible in the water near the surface of the water.

The lid portion 12 is formed in a substantially disk shape. Further, the lid portion 12 is fixed to the main body portion 11 by bolts in a state in which an O-ring (not shown) for waterproofing made of an elastic body is sandwiched between the main body portion 11. Further, the lid portion 12 has a first hole portion 12A and a second hole portion 12B (see FIG. 5) penetrating in the thickness direction, and the hole portions are formed to have a large diameter portion and are located above the large diameter portion. Two-stage shape of the small diameter portion smaller than the diameter of the large diameter portion. Further, the cable 5 is detachably connected by a cable clamp 12C formed at a central portion of the upper surface of the lid portion 12, and is electrically connected to a substrate 20 to be described later.

The first guiding portion 14 and the second guiding portion 15 have a concave portion for guiding the optical fiber sensor 31 to be described later, and protrude further outward than the optical fiber sensor 31 wound around the outer periphery of the casing 10. The protrusion. Further, the second guiding portion 15 has a through hole 15A that rotatably holds the rod 4 (see FIG. 4).

As shown in Figure 3, the ballast 16 is adjusted to float the float 2 The water line WL on the water is located at a position slightly below the joint portion between the lid portion 12 and the body portion 11.

The substrate 20 is fixed to the substrate supporting portion fixed to the lower surface of the lid portion 12 by bolts, and is housed in the casing 10 so as to extend in the vertical direction as shown in Fig. 4 . Further, the substrate 20 has a power supply circuit that supplies electric power to a light projecting element 32 to be described later, an amplification circuit that amplifies an output of the light receiving element 33, and the like, and is electrically connected to the elements.

Next, the configuration of the detecting unit 30 of the present embodiment will be described based on the third and fifth figures.

Fig. 5 is a schematic view showing the configuration of the detecting unit 30 according to the first embodiment of the present invention.

As shown in Fig. 5, the detecting unit 30 includes a fiber optic sensor (optical fiber) 31 provided on the outer peripheral surface of the casing 10, and a light projecting element (projecting light) for causing the detection light to enter from one end of the optical fiber sensor 31. a portion 32; and a light receiving element 33 that receives the detection light emitted from the other end of the optical fiber sensor 31.

Further, both end portions of the optical fiber sensor 31 are detachably connected to the first hole portion 12A and the second hole portion 12B of the lid portion 12 via the light projecting side connector 34 and the light receiving side connector 35, respectively.

The optical fiber sensor 31 is a single-core optical fiber cable formed of plastic, and is guided to the first guiding portion 14 and the second guiding portion 15 as shown in FIG. 3, and is substantially perpendicular to the longitudinal direction. The outer circumference of the casing 10 is disposed around the circumference.

Further, the optical fiber sensor 31 peels off the coating film over the predetermined detection range S to expose the core wire (optical fiber core wire) 31A. The detection range S is The upper and lower ranges are included with the water line WL. Further, the detection range S is an oil which is turbid and has a certain thickness, and is designed to be rapidly detected in the lower part of the water line WL in order to be quickly detected even when the oil is floated.

The light projecting element 32 is a light emitting diode (LED) that emits ultraviolet light having a wavelength of 360 nm to 370 nm. The light of this wavelength is called UV-A ultraviolet light, and although it does not have a strong destructive effect on living things, it has an effect of destructive or weak destruction of living things, and has an effect of suppressing the growth of algae. In addition, the light projecting element 32 is disposed on the lower surface side of the first hole portion 12A of the lid portion 12 so as to be opposed to the first collar member 32A.

The first collar member 32A is made of an electrically insulating member such as a synthetic resin.

The light receiving element 33 is a photodiode (PD) that receives ultraviolet light emitted from the light projecting element 32 and converts it into an electrical signal. Further, the light receiving element 33 is disposed on the lower surface side of the second hole portion 12B of the lid portion 12 so as to face the second collar member 33A with the light receiving surface facing the upper side.

The second collar member 33A is made of an electrically insulating member such as a synthetic resin.

The light projecting side connector 34 has a male connector 34A and a female connector 34B.

The male connector 34A is formed in a substantially cylindrical shape in which a screw portion is formed on the outer peripheral surface, and the inner diameter is formed to be sized to be inserted into the core wire 31A of the optical fiber sensor 31. Further, the male connector 34A is protruded upward from the upper surface side of the first hole portion 12A in the lid portion 12.

The female connector 34B is formed to be screwed into the male connector 34A The land portion is formed in a substantially cylindrical shape on the inner circumferential surface, and is connected to one end portion 311 of the optical fiber sensor 31.

Further, one end portion 311 of the optical fiber sensor 31 peels off the core wire 31A, and when the light-emitting side connector 34 is connected, the core wire 31A of the one end portion 311 is inserted into the inside of the male connector 34A.

The light receiving side connector 35 has a male connector 35A and a female connector 35B. Further, the male connector 35A is provided in the second hole portion 12B of the lid portion 12, and the female connector 35B is connected to the other end portion 312 of the optical fiber sensor 31. The other configuration of the light-receiving side connector 35 is the same as that of the light-emitting side connector 34, and the description thereof will be omitted.

Next, the operation of the optical oil detector 1 of the present embodiment will be described.

First, the description will be given of the fact that the floating body 2 of the optical oil detector 1 is placed in the drain pit P. Next, a method of detecting the oil in which the water in the drain pit P is detected by the optical oil detector 1 will be described. Finally, a process of suppressing the growth of algae when the algae adheres to the outer peripheral surface of the core wire 31A of the optical fiber sensor 31 will be described.

First, the floating body 2 is placed in the drain pit P.

As shown in Fig. 1B, water is stored in the drain pit P to the water level WL1. The floating body 2 connected to the rod 4 and the cable 5 floats upright in the vicinity of the water surface due to the buoyancy of the casing 10 and the weight of the ballast 16 when floating in the water in the drain pit P.

Here, when the water stored in the drain pit P is reduced to the water level WL2, the floating body 2 moves (falls) in the drain pit P in the vertical direction as the water level changes. Furthermore, the floating body 2 is connected by the rod 4 and the side wall bracket 41. On the side wall of the drain pit P, therefore moving within the movable range of the rod 4. Therefore, the floating body 2 does not apply a load to the cable 5 connected between the floating body 2 and the monitor 3.

Further, as shown in FIG. 3, the waterline WL when the cable floats on the water is at a position slightly lower than the joint portion between the lid portion 12 and the body portion 11. Further, the core wire 31A of the detection range S of the optical fiber sensor 31 is almost submerged.

Next, the optical oil detector 1 detects oil mixed with water in the drain pit P.

The light projecting element 32 of the floating body 2 receives power supply from the substrate 20 and injects ultraviolet light from one end portion 311 of the optical fiber sensor 31. The ultraviolet light is reflected and passed through the fiber optic sensor 31 and exits from the other end 312. The light receiving element 33 converts the received ultraviolet light into an electrical signal, and outputs the signal to the substrate 20. The substrate 20 amplifies the electrical signal input from the light receiving element 33 and outputs it to the monitor 3 via the cable 5.

Here, the oil is mixed into the water in the drain pit P, and the oil adheres to the outer peripheral surface of the core wire 31A in the detection range S of the optical fiber sensor 31. The refractive index of the above oil is larger than the refractive index of the outer peripheral portion of the core wire 31A. Therefore, the ultraviolet light reflected and passed through the core wire 31A is refracted on the outer peripheral surface of the core wire 31A, and at least a part of the ultraviolet light leaks from the outer peripheral surface to the outside. When the ultraviolet light leaks, the amount of ultraviolet light emitted from the end portion of the optical fiber sensor 31 on the light-receiving element 33 side is reduced, and therefore the amount of electrical signals output from the light-receiving element 33 to the substrate 20 is also reduced. As a result, since the amount of electrical signals output from the substrate 20 to the monitor 3 is reduced, the monitor 3 is tied An alarm signal for oil detection or the like is generated by the decrease of the electrical signal.

Finally, a process of suppressing the growth of algae when the algae adheres to the outer peripheral surface of the core wire 31A of the optical fiber sensor 31 will be described.

In the water stored in the drainage pit P, there are few algae floating freely. Further, the algae adhere to the outer peripheral surface of the core wire 31A of the detection range S of the optical fiber sensor 31. In this state, the attached algae grows slowly as time passes, hindering the normal detection of the optical oil detector 1. However, in the present embodiment, even if a small amount of ultraviolet light leaks from the outer peripheral surface of the core wire 31A in the normal use state, the algae is irradiated with ultraviolet light.

Since the ultraviolet light system has the growth resistance of algae, it is possible to suppress the growth of algae on the outer peripheral surface of the core wire 31A of the detection range S.

Therefore, according to the present embodiment, the following effects can be obtained.

In the present embodiment, the growth of algae can be suppressed on the outer peripheral surface of the core wire 31A of the detection range S of the optical fiber sensor 31. Therefore, it is possible to avoid the problem that the optical oil detector 1 cannot detect the presence or absence of oil in the water due to the adhesion of the algae. Therefore, in the present embodiment, the normal detection characteristics of the optical oil detector 1 can be maintained for a long period of time.

(Second embodiment)

The configuration of the detecting unit 30 of the optical oil detector 1 of the present embodiment will be described with reference to Fig. 6 . In addition, the configurations other than the substrate 20 and the detecting unit 30 of the present embodiment are the same as those of the first embodiment, and thus the description thereof will be omitted. In the sixth embodiment, the same components as those of the detecting unit 30 of the first embodiment shown in Fig. 5 are denoted by the same reference numerals, and the description thereof is omitted. Description.

First, the configuration of the detecting unit 30 of the present embodiment will be described based on Fig. 6 .

Fig. 6 is a schematic view showing the configuration of the detecting unit 30 according to the second embodiment of the present invention.

As shown in Fig. 6, the detecting unit 30 includes a concentrator 36 as an element other than the constituent elements described in the first embodiment, and refracts light incident from the opposite side surfaces to be emitted from the upper surface; The second light projecting element (second light projecting unit) 37 causes the detection light (second detection light) to enter from one side surface of the concentrator 36.

The concentrator 36 has an entrance hole 36A for allowing light to be incident on the opposite side faces, and an exit hole 36B for refracting light incident from each of the incident holes 36A and emitting from the upper surface. Further, the injection hole 36B of the concentrator 36 is provided on the lower surface side of the first hole portion 12A of the lid portion 12 so as to face the core wire 31A located above.

The second light projecting element 37 is a light emitting diode (LED) that emits visible light having a wavelength of 650 nm to 700 nm. Further, the light projecting surface of the second light projecting element 37 faces the incident hole 36A of one of the concentrators 36, and is provided on the side surface of the concentrator 36 by the second mounting bracket 37A.

The light projecting surface of the light projecting element 32 faces the other incident hole 36A of the concentrator 36, and is provided on the side surface of the concentrator 36 by the first mounting bracket 32B.

The light receiving element 33 is a photodiode (PD) that receives visible light that is emitted by the second light projecting element 37 and converts it into an electrical signal.

Next, the configuration of the substrate 20 of the present embodiment will be described.

The substrate (switching unit) 20 has a switching circuit for selectively switching the light projection from the light projecting element 32 and the second light projecting element 37 in addition to the power supply circuit and the amplifier circuit described in the first embodiment. . The switching circuit may be configured to perform a switching operation preset by a semiconductor element or the like. Furthermore, the switching circuit may be configured to change the switching operation by a change in a program or the like.

Next, the operation of the optical oil detector 1 of the present embodiment will be described. In addition, the detection operation by the detecting unit 30 in the present embodiment is the same as that of the first embodiment, and thus the description thereof will be omitted.

First, the operation of the switching circuit of the substrate 20 will be described.

The switching circuit of the substrate 20 selectively switches the light projection from the light projecting element by selectively switching the power to the light projecting element 32 and the second light projecting element 37. Further, normally, the visible light is emitted by the second light projecting element 37, and the presence or absence of oil in the water is detected. Further, the light projecting element 32 emits light for a certain period of time for a predetermined period of time, and the growth of the algae adhering to the outer peripheral surface of the core wire 31A of the detection range S of the optical fiber sensor 31 is suppressed.

In addition, the light emission time by each light-emitting element can be appropriately changed in consideration of, for example, the ease of attachment of algae, the speed of growth, and the like.

Next, an operation of emitting visible light emitted from the second light projecting element 37 from the concentrator 36 will be described.

When the substrate 20 supplies electric power to the second light projecting element 37, the second light projecting element 37 causes visible light to enter the incident hole 36A of the concentrator 36. The visible light incident on the incident hole 36A is refracted inside the concentrator 36, and is incident from the concentrator 36. The exit hole 36B is incident on one end portion 311 of the optical fiber sensor 31. The light receiving element 33 receives the visible light emitted from the other end portion 312 of the optical fiber sensor 31, converts the visible light into an electrical signal, and outputs the signal to the substrate 20. The substrate 20 amplifies the electrical signal input from the light receiving element 33 and outputs it to the monitor 3 via the cable 5. In addition, the operation when the oil adheres to the outer surface of the core wire 31A of the detection range S of the optical fiber sensor 31 is the same as that of the first embodiment, and thus the description thereof will be omitted.

In addition, the operation of emitting ultraviolet light emitted from the light projecting element 32 from the concentrator 36 will be described.

When the substrate 20 supplies electric power to the light projecting element 32, the light projecting element 32 causes ultraviolet light to be incident on the incident hole 36A of the concentrator 36. The ultraviolet light incident on the incident hole 36A is refracted inside the concentrator 36, and is incident from the exit hole 36B to one end portion 311 of the optical fiber sensor 31. Even in the normal use state, a trace amount of ultraviolet light leaks from the outer peripheral surface of the core wire 31A of the detection range S. Therefore, during the period in which the substrate 20 supplies electric power to the light projecting element 32, the growth of the algae adhering to the outer peripheral surface of the core wire 31A can be suppressed.

Therefore, according to the second embodiment, in addition to the effects obtained by the first embodiment, the following effects can be obtained.

The ultraviolet light system used in the present embodiment has a property of accelerating deterioration of the optical fiber sensor 31. However, in the present embodiment, the ultraviolet light emitted from the light projecting element 32 and the visible light emitted from the second light projecting element 37 are switched and used. Therefore, the life of the optical fiber sensor 31 can be extended as compared with the case where the ultraviolet light is constantly projected.

Further, the operation sequence or each configuration shown in the above embodiment The shapes, combinations, and the like of the members are merely examples, and various modifications can be made depending on the program conditions, design requirements, and the like without departing from the scope of the invention.

For example, in the above embodiment, the wavelength of the ultraviolet light emitted from the light projecting element 32 is 360 nm to 370 nm. However, the present invention is not limited to this wavelength, and the growth of algae can be suppressed even when a wavelength of 280 nm to 400 nm is used.

Further, the wavelength of the ultraviolet light emitted from the light projecting element 32 may be set to 200 nm to 280 nm. These wavelengths of ultraviolet light are called UV-C ultraviolet light and have a strong destructive effect on living things. Therefore, by using the ultraviolet light of the same wavelength, the algae adhering to the outer peripheral surface of the core wire 31A of the detection range S can be eliminated, and the growth of the algae can be more strongly suppressed.

Further, in the above embodiment, an LED is used as the light projecting element 32 and the second light projecting element 37. However, an electric bulb, a fluorescent lamp, or the like may be used as a member for projecting visible light, and a UV lamp or the like may be used as a member for projecting ultraviolet light.

In the foregoing embodiment, a fiber optic cable of a single core wire formed of plastic is used. However, it is also possible to use a quartz fiber formed of quartz instead of the plastic optical fiber. Since the quartz fiber is highly durable against ultraviolet light, the replacement period of the fiber sensor 31 is longer than when the plastic fiber is used.

It is also possible to use a fiber optic cable composed of a plurality of core wires instead of a plastic optical fiber and a quartz optical fiber.

Further, in the above embodiment, the optical oil detector 1 is configured to have the floating body 2 and float near the water surface. However, the present invention can also be used in a state where it is fixed to a detection site without using the floating body 2. Learning oil detector. For the fixed optical oil detector, a detector disclosed in, for example, Japanese Patent Publication No. Sho 59-20092 can be used.

In the second embodiment, the wavelength of the visible light emitted by the second light projecting element 37 is 650 nm to 700 nm. However, the present invention is not limited to this wavelength, and a wavelength of 400 nm to 650 nm may be used.

Further, in the second embodiment of the present invention, the light emitted from the light projecting element 32 and the second light projecting element 37 is condensed and emitted by the concentrator 36. However, the present invention can also use a light projecting element that projects two kinds of light from one light projecting element. In the light projecting element, the selection of the light to be emitted is performed based on a control signal input from the substrate 20 to the light projecting element. Further, when the light projecting element is used, since the concentrator 36 is not required, the configuration adopted in the first embodiment is used.

Further, any concentrating/refracting method may be employed for the concentrator 36 used in the second embodiment. For example, an optical coupler such as a cymbal, a mirror, and a multiplexer can also be used.

Further, in the second embodiment described above, the light projection from the light projecting element 32 and the second light projecting element 37 is electrically switched by the power supply from the substrate 20. However, the present invention can also perform the switching of the above-described light projecting by mechanical means such as a shutter or the like. At this time, the switching circuit of the substrate controls the opening and closing of the shutter or the like.

According to the present invention, since the growth of the algae on the outer peripheral surface of the optical fiber can be suppressed, it is possible to avoid the problem that the optical oil detector cannot detect the presence or absence of oil in the water due to the adhesion of the algae. Therefore, according to the present invention, the normal detection characteristics of the optical oil detector 1 can be maintained for a long period of time.

1‧‧‧Optical oil detector

2‧‧‧ floating body

3‧‧‧Monitor

4‧‧‧ rod

5‧‧‧ cable

10‧‧‧shell

11‧‧‧ Body Department

12‧‧‧ 盖部

12A‧‧‧1st hole

12B‧‧‧2nd hole

13‧‧‧ Cover

14‧‧‧1st guide

15‧‧‧2nd Guide

15A‧‧‧through hole

16‧‧‧ ballast

20‧‧‧Substrate (switching unit)

30‧‧‧Detection Department

31‧‧‧Fiber optic sensor (optical fiber)

32‧‧‧Lighting element (projection department)

31A‧‧‧core wire (optical fiber core wire)

32A‧‧‧1st collar member

33‧‧‧Light-receiving components

33A‧‧‧2nd collar member (1st mounting bracket)

34‧‧‧Lighting side connector

34A, 35A‧‧‧ male connectors

34B, 35B‧‧‧ female connector

35‧‧‧Light-receiving side connector

36‧‧‧ concentrator

36A‧‧‧Injection hole

36B‧‧‧ shot hole

37‧‧‧2nd Projector (2nd Projector)

37A‧‧‧2nd mounting bracket

41‧‧‧ Side brackets

311‧‧‧ one end

312‧‧‧Other end

P‧‧‧Drainage pit

S‧‧‧Detection range

WL‧‧‧ waterline

WL1, WL2‧‧‧ water level

Fig. 1A is a plan view showing an optical oil detector 1 according to the first embodiment of the present invention.

Fig. 1B is a side view showing the optical oil detector 1 and the drain pit P according to the first embodiment of the present invention.

Fig. 2 is a perspective view showing the configuration of the floating body 2 according to the first embodiment of the present invention.

Fig. 3 is a cross-sectional view showing the floating body 2 according to the first embodiment of the present invention.

Fig. 4 is a sectional view taken along line A-A of Fig. 3.

Fig. 5 is a schematic view showing the configuration of the detecting unit 30 according to the first embodiment of the present invention.

Fig. 6 is a schematic view showing the configuration of the detecting unit 30 according to the second embodiment of the present invention.

12‧‧‧ 盖部

12A‧‧‧1st hole

12B‧‧‧2nd hole

30‧‧‧Detection Department

31‧‧‧Fiber optic sensor (optical fiber)

31A‧‧‧core wire (optical fiber core wire)

32‧‧‧Lighting element (projection department)

32A‧‧‧1st collar member

33‧‧‧Light-receiving components

33A‧‧‧2nd collar member (1st mounting bracket)

34‧‧‧Lighting side connector

34A, 35A‧‧‧ male connectors

34B, 35B‧‧‧ female connector

35‧‧‧Light-receiving side connector

311‧‧‧ one end

312‧‧‧Other end

Claims (6)

An optical oil detector detects an oiler by detecting light from a light projecting portion of an optical fiber, and the optical oil detector is characterized in that the detection light is light having a wavelength of growth resistance of algae And the optical oil detector includes: a second light projecting unit that causes a second detection light having a wavelength different from the wavelength to enter the optical fiber; and a switching unit that selectively switches the light projecting unit and the first 2 cast light of the light projection department. An optical oil detector according to claim 1, wherein the detection light system is ultraviolet light. An optical oil detector according to claim 2, wherein the ultraviolet light has a wavelength of from 200 nm to 280 nm. An optical oil detector according to claim 2, wherein the ultraviolet light has a wavelength of from 280 nm to 400 nm. The optical oil detector according to claim 1, wherein the second detection light system is visible light. An optical oil detector according to claim 1, wherein the optical fiber is provided in a floating body.