Underwater fluorescence matrix measuring device

Abstract

This invention provides an underwater fluorescence matrix measuring device that can perform continuous EEM spectroscopy measurements of objects in the surrounding environment while the device is submerged in water. [Solution] The underwater fluorescence matrix measuring device 100 comprises excitation light sources 21, 22, and 23; a light receiving unit 31 that receives fluorescence emitted from the object to be measured; a spectroscopic unit 32 having a spectroscopic element 322 that spectrally analyzes the fluorescence received by the light receiving unit 31 and a linear image sensor 323 having a plurality of light receiving elements arranged along the spectral direction of the spectroscopic element 322; a control unit 41 that generates EEM information based on excitation wavelength information indicating the excitation wavelength of the excitation light and light reception intensity information when the object to be measured is sequentially irradiated with excitation light of different wavelength bands; a bottomed cylindrical housing 11; and a lid 12 fitted to the opening portion of the housing 11 so as to seal the inside of the housing 11.

Description

Technical Field

[0001] The present invention relates to an underwater fluorescence matrix measuring device.

Background Art

[0002] There has been proposed a method of discriminating the type of a measurement object by obtaining excitation-fluorescence matrix (EEM) information about the measurement object by measuring the wavelength spectrum of fluorescence generated from the measurement object irradiated with excitation light while stepwise changing the excitation wavelength for irradiating the measurement object and the fluorescence wavelength for measurement within a predetermined excitation wavelength range and a predetermined fluorescence wavelength range (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document ①

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, dissolved organic matter (DOM) in water such as the sea and rivers is a fundamental existence in the carbon cycle of the earth's hydrosphere. Therefore, elucidating its behavior has become an urgent issue in elucidating the carbon cycle of the earth's surface including the carbon absorption mechanism of the hydrosphere. For this reason, it is required to analyze the temporal change in the components of DOM in water such as the sea and rivers. For specifying this DOM, DOM can be accurately specified by adopting the EEM measurement method as described in Patent Document 1. Therefore, in order to accurately grasp the temporal change in the components of DOM in water such as the sea and rivers, there is a demand for a fluorescence spectrum measuring device that can continuously measure information on the wavelength band of excitation light when DOM is excited with excitation light in a plurality of wavelength bands and information on the wavelength spectrum of fluorescence from DOM while being left in water such as the sea and rivers.

[0005] The present invention has been made in view of the above-mentioned reasons, and aims to provide an underwater fluorescence matrix measuring device that can perform continuous EEM spectroscopic measurements on objects present in the surroundings while the device is placed in water. [Means for solving the problem]

[0006] The underwater fluorescence matrix measuring device according to the present invention is Multiple excitation light sources that irradiate the object to be measured with excitation light in different wavelength bands to excite the object, A light receiving unit that receives fluorescence emitted from the object to be measured when the object to be measured is excited, A spectroscopic unit having a spectroscopic element that spectrally analyzes fluorescence received by the light receiving unit, and a plurality of light receiving elements arranged along the spectral direction of the spectroscopic element and that receive light spectrally analyzed by the spectroscopic element, An EEM (Excitation-Emission Matrix) information generation unit generates EEM information based on excitation wavelength information indicating the wavelength band of the excitation light when the object to be measured is sequentially irradiated with excitation light of different wavelength bands from the plurality of excitation light sources, and light reception intensity information indicating the intensity of the light received by each of the plurality of photoreceiving elements. A bottomed cylindrical housing containing the plurality of excitation light sources, the light receiving unit, the spectral unit, and the EEM information generation unit inside, The lid is fitted to the opening of the housing so as to seal the inside of the housing, and has a plurality of first through holes that penetrate from the inside to the outside of the housing and face each of the plurality of excitation light sources, and a second through hole that penetrates from the inside to the outside of the housing and faces the light receiving unit, the plurality of first through holes being closed by a first optical member that is transparent to the excitation light emitted from the plurality of excitation light sources, and the second through hole being closed by a second optical member that is transparent to the fluorescence emitted from the object to be measured that is present around the housing. [Effects of the Invention]

[0007] The present invention comprises a housing that houses multiple excitation light sources, a light receiving unit, a spectroscopic unit, and an EEM information generation unit, and a lid fitted to the opening of the housing so as to seal the inside of the housing. The lid has multiple first through-holes facing each of the multiple excitation light sources and a second through-hole facing the light receiving unit, with the multiple first through-holes being closed by a first optical member and the second through-holes being closed by a second optical member. As a result, water can not enter the inside of the housing even when the housing is placed in water, so that continuous EEM spectroscopic measurements can be performed on objects present in the surroundings while the housing is placed in water. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic cross-sectional view of an underwater fluorescence matrix measuring device according to an embodiment of the present invention. [Figure 2] This is a cross-sectional view taken along line AA in Figure 1 of the underwater fluorescence matrix measuring device according to the embodiment. [Figure 3] The underwater fluorescence matrix measuring device according to an embodiment is shown, where (A) is a schematic front view seen from one direction, and (B) is a cross-sectional view of a portion of (A) along the line BB. [Figure 4] This figure shows the wavelength spectrum of fluorescence of the object being measured. [Figure 5] This is a block diagram showing the configuration of the information processing unit of the underwater fluorescence matrix measuring device according to the embodiment. [Figure 6] This figure shows an example of the information stored by the setting storage unit according to the embodiment. [Figure 7] This flowchart shows an example of the flow of the underwater fluorescence matrix measurement process performed by the underwater fluorescence matrix measurement device according to the embodiment. [Figure 8] This figure shows an example of the fluorescence wavelength spectrum of a measurement target measured by the underwater fluorescence matrix measuring device according to the embodiment. [Modes for carrying out the invention]

[0009] The underwater fluorescence matrix measuring apparatus according to the embodiment of the present invention comprises a plurality of excitation light sources, a light receiving unit, a spectral unit, an EEM (Excitation-Emission Matrix) information generation unit, a housing, and a lid. The plurality of excitation light sources irradiate the object to be measured with excitation light of different wavelength bands to excite the object to be measured. The light receiving unit receives the fluorescence emitted from the object to be measured when it is excited. The spectral unit has a spectral element that spectrally analyzes the fluorescence received by the light receiving unit, and a plurality of light receiving elements arranged along the spectral direction of the spectral element and receiving the light spectrally analyzed by the spectral element. The EEM information generation unit generates EEM information based on wavelength band information indicating the wavelength band of the excitation light when the object to be measured is sequentially irradiated with excitation light of different wavelength bands from the plurality of excitation light sources, and fluorescence intensity information indicating the intensity of the light received by each of the plurality of light receiving elements. The housing is a bottomed cylindrical shape and houses the plurality of excitation light sources, the light receiving unit, the spectral unit, and the EEM information generation unit inside. The cover is fitted to the opening of the housing so as to seal the inside of the housing. The cover also has multiple first through-holes that penetrate from the inside to the outside of the housing, facing each of the multiple excitation light sources, and a second through-hole that penetrates from the inside to the outside of the housing, facing the light receiving unit. The multiple first through-holes are closed by a first optical member that is transparent to the excitation light emitted from the multiple excitation light sources, and the second through-holes are closed by a second optical member that is transparent to the fluorescence emitted from the object to be measured that is present around the housing.

[0010] As shown in Figures 1 and 2, the underwater fluorescence matrix measuring device 100 according to this embodiment comprises a plurality (five in Figure 2) excitation light sources 21, 22, 23, 24, and 25, a light receiving unit 31, a spectroscopic unit 32, a control unit 41, a housing 11, a lid 12, and a battery 51. This underwater fluorescence matrix measuring device 100 is used while stationary in water such as the sea or a river. For example, the underwater fluorescence matrix measuring device 100 is stationary while suspended in the sea from a buoy moored on the ocean. The housing 11 is formed, for example, from metal in a bottomed cylindrical shape and houses the five excitation light sources 21, 22, 23, 24, and 25, the light receiving unit 31, the spectroscopic unit 32, the control unit 41, and the battery 51 inside. The optical axes of the five excitation light sources 21, 22, 23, 24, and 25 and the optical axis of the light receiving unit 31 are set to intersect with each other at approximately position FP1.

[0011] The cover 12 is formed, for example, from metal in a disc shape and is fitted to the opening on the -Z direction side of the housing 11 so as to seal the inside of the housing 11. A waterproof O-ring (not shown) is provided between the opening end face of the housing 11 and the housing 11 side of the periphery of the cover 12. In addition, as shown in Figure 3(A), a recess 12a is formed in the cover 12 approximately in the center on the -Z direction side, and five first through holes 12c and one second through hole 12b are provided through the inside of the recess 12a, opening to the inside. As shown in Figure 2, the first through holes 12c are arranged opposite to the excitation light sources 21, 22, 23, 24, and 25, respectively, and the second through hole 12b is arranged opposite to the light receiving unit 31. Also, as shown in Figure 3(B), the first through holes 12c penetrate from the inside to the outside of the housing 11 along the optical axis J21 direction of the excitation light source 21. Furthermore, the other four first through-holes 12c each penetrate from inside to outside the housing 11 along the optical axis directions of the excitation light sources 22, 23, 24, and 25. As shown in Figure 3(A), each first through-hole 12c is closed by a transparent, disc-shaped first optical member 131 that is not affected by the excitation light emitted from the excitation light sources 21, 22, 23, 24, and 25. The second through-hole 12b is also closed by a transparent, disc-shaped second optical member 132 that is not affected by the fluorescence emitted from the object to be measured surrounding the housing 11. The first optical member 131 and the second optical member 132 are formed from, for example, transparent quartz glass. The first optical member 131 and the second optical member 132 may also have a lens-like shape.

[0012] The excitation light sources 21, 22, 23, 24, and 25 irradiate the measurement object with excitation light in different wavelength bands for exciting the measurement object. As shown in Fig. 3(B), each of the excitation light sources 21, 22, 23, 24, and 25 includes a bottomed cylindrical lens barrel 201, a light-emitting module 202 disposed on the bottom side of the lens barrel 201, and a lens 203 disposed along the axial direction of the lens barrel 201. The posture of the excitation light sources 21, 22, 23, 24, and 25 and the focal length in the corresponding wavelength band of the excitation light of the lens 203 employed are set so that the excitation light emitted from each of the excitation light sources 21, 22, 23, 24, and 25 is focused on one focal point P1 shown in Fig. 1. The light-emitting module 202 has a light-emitting part using, for example, an LED (Light Emitting Diode) element, and lights up the light-emitting part when current is supplied from the control unit 41. For example, assume that the measurement object contains a protein-like substance, a humus-like substance, and a substance derived from Escherichia coli. In this case, as shown in Fig. 4, if the wavelengths corresponding to the intensity peaks of the excitation light emitted from the excitation light sources 21, 22, 23, 24, and 25 are set to 265 nm, 310 nm, 365 nm, 410 nm, and 500 nm, the fluorescence components from the protein-like substance, the humus-like substance, and the substance derived from Escherichia coli can be separated respectively.

[0013] Returning to Fig. 3(B), the light-receiving unit 31 receives the fluorescence emitted from the measurement object when the measurement object is excited. The light received by the light-receiving unit 31 enters the spectroscopic unit 32 through an optical transmission cable 33 having an optical fiber. The light-receiving unit 31 has an optical system for making the received light enter the optical fiber of the optical transmission cable 33.

[0014] Returning to FIG. 1, the spectroscopic unit 32 includes a spectroscopic element 322 that spectroscopically analyzes the fluorescence received by the light receiving unit 31, and a linear image sensor 323 having a plurality of light receiving elements arranged along the spectroscopic direction of the spectroscopic element 322 and receiving the light spectroscopically analyzed by the spectroscopic element 322. The spectroscopic unit 32 also includes an incident slit 321 interposed between the end portion of the optical fiber of the optical transmission cable 33 disposed inside the spectroscopic unit 32 and the spectroscopic element 322, and a measurement information generation unit 324 having a drive circuit for the linear image sensor 323 and generating measurement information. The spectroscopic element 322 is, for example, a so-called reflective concave grating, and has a function of condensing the light spectroscopically analyzed onto the region where the plurality of light receiving elements of the linear image sensor 323 are arranged while spectroscopically analyzing the light incident from the incident slit 321. The measurement information generation unit 324 generates measurement information including light reception intensity information indicating the intensity of the light received by each of the plurality of light receiving elements of the linear image sensor 323 and light receiving element identification information for identifying the corresponding light receiving element, and outputs the measurement information to the control unit 41.

[0015] The battery 51 is a secondary battery such as a lead-acid battery, a lithium-ion secondary battery, or an all-solid-state battery, and supplies DC power to the spectroscopic unit 32 and the control unit 41.

[0016] As shown in FIG. 5, the control unit 41 includes a processing unit 401 having a processor and a memory, a lighting circuit 402 for lighting the excitation light sources 21, 22, 23, 24, 25, an interface 403 for acquiring the above-described measurement information input from the spectroscopic unit 32 and transferring the acquired measurement information to the processing unit 401, a timing unit 404, and a communication module 405 for communicating with an external device 200. The lighting circuit 402 receives power supply from the battery 51 and lights or turns off the excitation light sources 21, 22, 23, 24, 25 based on a control signal input from the processing unit 401.

[0017] In the processing unit 401, the processor reads and executes a program stored in memory, thereby functioning as an excitation light source control unit 411, a measurement information acquisition unit 412, an EEM (Excitation-Emission Matrix) information generation unit 413, an EEM information notification unit 414, and a setting acquisition unit 415. The memory also includes a setting storage unit 431, a wavelength information storage unit 432, an EEM information storage unit 433, and a measurement information buffer 421. As shown in Figure 6, the setting storage unit 431 stores information indicating the irradiation duration when excitation light is continuously irradiated onto the object to be measured by the excitation light sources 21, 22, 23, 24, and 25, and usage flag information indicating whether the excitation light sources 21, 22, 23, 24, and 25 are being used, in association with excitation light source identification information that identifies the excitation light sources 21, 22, 23, 24, and 25. In the example shown in Figure 6, the peak wavelengths of the excitation light emitted from excitation light sources 21, 22, 23, 24, and 25, identified by excitation light source identification information ID[0], ID[1], ID[2], ID[3], ID[4], and ID[5], respectively, are "265nm", "280nm", "340nm", "365nm", and "405nm", and the irradiation durations are set to "50sec", "20sec", "50sec", "10sec", and "10sec". It also shows that excitation light source 22, identified by excitation light source identification information ID[1], is not used in the measurement. Here, the irradiation duration for excitation light sources 21, 22, 23, 24, and 25 is set so that the integrated amount of excitation light irradiated onto the object to be measured from excitation light sources 21, 22, 23, 24, and 25 within the irradiation duration is equal. In Figure 6, the intensity of the excitation light emitted from each of the excitation light sources 21, 22, 23, 24, and 25, identified by excitation light source identification information ID[0], ID[1], ID[2], ID[3], ID[4], and ID[5], is set to "40 mW / cm²". 2 "100mW / cm 2 "35mW / cm 2 "580mW / cm 2 "550mW / cm 2 This shows the case where...

[0018] The wavelength information storage unit 432 stores wavelength information indicating the central wavelength of the wavelength band of light received by each of the multiple photodetectors constituting the linear image sensor 323 of the spectral unit 32, in association with photodetector identification information that identifies the photodetector. The wavelength information storage unit 432 also stores wavelength information indicating the wavelength at the intensity peak of the wavelength spectrum of the excitation light emitted by the excitation light sources 21, 22, 23, 24, and 25, in association with excitation light source identification information.

[0019] The excitation light source control unit 411 sequentially lights up the excitation light sources 21, 22, 23, 24, and 25 one by one. The excitation light source control unit 411 selects one of the five excitation light sources 21, 22, 23, 24, and 25 to light up. Then, the excitation light source control unit 411 identifies the irradiation duration information corresponding to the excitation light source identification information of the selected excitation light source 21, 22, 23, 24, and 25, which is stored in the setting memory unit 431. Next, the excitation light source control unit 411 generates a control signal to light up the selected excitation light source 21, 22, 23, 24, and 25 for the irradiation duration indicated by the identified irradiation duration information, and outputs it to the lighting circuit 402. As a result, the irradiation of the object to be measured with excitation light from the selected excitation light source 21, 22, 23, 24, and 25 begins. At this time, the excitation light source control unit 411 notifies the measurement information acquisition unit 412 of irradiation start notification information indicating the start of irradiation with excitation light and excitation light source identification information identifying the selected excitation light source 21, 22, 23, 24, 25. The excitation light source control unit 411 also notifies the EEM information generation unit 413 of the excitation light source identification information identifying the selected excitation light source 21, 22, 23, 24, 25. Subsequently, based on the elapsed time since the start of lighting the excitation light source 21, 22, 23, 24, 25 measured by the timing unit 404, the excitation light source control unit 411 determines that a specified irradiation duration has elapsed since the start of excitation light irradiation, and generates a control signal to turn off the lit excitation light source 21, 22, 23, 24, 25 and outputs it to the lighting circuit 402. This ends the irradiation of the measurement target with excitation light from the selected excitation light source 21, 22, 23, 24, 25. At this time, the excitation light source control unit 411 notifies the measurement information acquisition unit 412 of the irradiation completion notification information indicating that the irradiation of excitation light has ended.

[0020] When the excitation light source control unit 411 notifies the measurement information acquisition unit 412 of the irradiation start notification, the unit 412 begins acquiring measurement information continuously input from the spectral unit 32. Thereafter, each time the measurement information acquisition unit 412 acquires measurement information continuously input from the spectral unit 32, it extracts the light reception intensity information and light receiving element identification information contained in the measurement information and stores them in the measurement information buffer 421 in association with the excitation light source identification information notified by the excitation light source control unit 411. Furthermore, when the excitation light source control unit 411 notifies the measurement information acquisition unit 412 of the irradiation end notification, the unit 412 terminates the acquisition of measurement information from the spectral unit 32.

[0021] The EEM information generation unit 413 generates EEM information based on wavelength band information indicating the wavelength band of the excitation light when the object to be measured is sequentially irradiated with excitation light of different wavelength bands from the excitation light sources 21, 22, 23, 24, and 25, and light reception intensity information indicating the intensity of the light received by each of the multiple photodetectors. The EEM information generation unit 413 refers to the wavelength information stored in the wavelength information storage unit 432 to identify the wavelength corresponding to each of the photodetector identification information stored in the measurement information buffer 421, and generates wavelength spectrum information showing the relationship between the identified wavelength and the light reception intensity at that wavelength. The EEM information generation unit 413 also identifies the wavelength of the excitation light indicated by the wavelength information corresponding to the excitation light source identification information notified by the excitation light source control unit 411, which is stored in the wavelength information storage unit 432. Then, the EEM information generation unit 413 stores the generated wavelength spectrum information in the EEM information storage unit 433, associating it with the excitation light wavelength information indicating the identified excitation light wavelength.

[0022] The EEM information notification unit 414 generates EEM notification information, including wavelength spectrum information and excitation light wavelength information, which is stored in the EEM information storage unit 433, whenever a preset EEM information notification period arrives. The EEM information notification unit 414 then transmits the generated EEM notification information to the external device 200 via the communication module 405.

[0023] The setting acquisition unit 415 acquires setting notification information, including excitation light source identification information, irradiation duration information, and usage flag information, from the external device 200 via the communication module 405, and extracts this information from the acquired setting notification information. Then, the setting acquisition unit 415 uses this extracted information to update the excitation light source identification information, irradiation duration information, and usage flag information stored in the setting storage unit 431.

[0024] Next, an example of the flow of the underwater fluorescence matrix measurement process performed by the underwater fluorescence matrix measurement device according to this embodiment will be explained with reference to Figure 7. Here, it is assumed that the setting storage unit 431 has in advance stored irradiation duration information and usage / usage flag information for each of the excitation light sources 21, 22, 23, 24, and 25. First, the setting acquisition unit 415 determines whether or not it has acquired the aforementioned setting notification information from the external device 200 via the communication module 405 (step S101). If the setting acquisition unit 415 determines that it has not acquired the setting notification information (step S101: No), the process in step S103, which will be described later, is executed. On the other hand, if the setting acquisition unit 415 determines that it has acquired the setting notification information (step S101: Yes), it extracts the excitation light source identification information, irradiation duration information, and usage / usage flag information contained in the setting notification information, and uses this extracted information to update the excitation light source identification information, irradiation duration information, and usage / usage flag information stored in the setting storage unit 431 (step S102).

[0025] Next, the excitation light source control unit 411 selects one of the five excitation light sources 21, 22, 23, 24, and 25, and identifies the irradiation duration corresponding to the excitation light source identification information of the selected excitation light source 21, 22, 23, 24, and 25 stored in the setting storage unit 431 (step S103). Subsequently, the excitation light source control unit 411 generates a control signal to turn on the selected excitation light source 21, 22, 23, 24, and 25 and outputs it to the lighting circuit 402. This starts the irradiation of the object to be measured with excitation light from the selected excitation light source 21, 22, 23, 24, and 25. At this time, the excitation light source control unit 411 notifies the measurement information acquisition unit 412 of the aforementioned irradiation start notification information. Then, when the measurement information acquisition unit 412 receives the irradiation start notification information, it starts acquiring measurement information that is continuously input from the spectral unit 32 (step S104). Thereafter, each time measurement information is acquired, the measurement information acquisition unit 412 extracts the light reception intensity information and light receiving element identification information contained in the acquired measurement information, and stores them in the measurement information buffer 421 in association with the excitation light source identification information notified by the excitation light source control unit 411.

[0026] Subsequently, the excitation light source control unit 411 determines, based on the elapsed time since the start of lighting one of the excitation light sources 21, 22, 23, 24, 25, which is timed by the timing unit 404, whether or not the specified irradiation duration has elapsed since the start of excitation light irradiation (step S105). Here, the excitation light source control unit 411 repeatedly executes the process in step S105 as long as it determines that the specified irradiation duration has not yet elapsed since the start of excitation light irradiation (step S105: No). On the other hand, if the excitation light source control unit 411 determines that the specified irradiation duration has elapsed since the start of excitation light irradiation (step S105: Yes), it generates a control signal to turn off the lit excitation light sources 21, 22, 23, 24, 25 and outputs it to the lighting circuit 402. As a result, the irradiation of the measurement target with excitation light from the selected excitation light source 21, 22, 23, 24, 25 ends. At this time, the excitation light source control unit 411 notifies the measurement information acquisition unit 412 of irradiation completion notification information indicating that the irradiation of excitation light has ended. When the measurement information acquisition unit 412 receives the irradiation completion notification information, it terminates the acquisition of measurement information from the spectral unit 32 (step S106). In the end, the excitation light source control unit 411 repeats the process of steps S103 to S106 described above to select one of the excitation light sources 21, 22, 23, 24, and 25, identifies the irradiation duration set for the selected excitation light source 21, 22, 23, 24, and 25, and controls the lighting state of the excitation light sources 21, 22, 23, 24, and 25 to repeatedly irradiate the object to be measured with excitation light from the selected excitation light source 21, 22, 23, 24, and 25 for the specified irradiation duration.

[0027] Next, the EEM information generation unit 413 refers to the wavelength information stored in the wavelength information storage unit 432 to identify the wavelengths corresponding to each of the photodetector identification information stored in the measurement information buffer 421, and generates wavelength spectrum information showing the relationship between the identified wavelengths and the light received intensity at those wavelengths. The EEM information generation unit 413 also identifies the wavelength of the excitation light indicated by the wavelength information corresponding to the excitation light source identification information notified from the excitation light source control unit 411, which is stored in the wavelength information storage unit 432. Then, the EEM information generation unit 413 stores the generated wavelength spectrum information in the EEM information storage unit 433, associating it with the excitation light wavelength information indicating the identified excitation light wavelength (step S107). As a result, the EEM information storage unit 433 stores EEM information including excitation wavelength information indicating the center wavelength of the excitation light wavelength band when the measurement target is sequentially irradiated with excitation light of different wavelength bands from the excitation light sources 21, 22, 23, 24, and 25, and wavelength spectrum information.

[0028] Next, the EEM information notification unit 414 determines whether or not the aforementioned EEM information notification time has arrived (step S108). If the EEM information notification unit 414 determines that the EEM information notification time has not yet arrived (step S108: No), the process in step S101 is executed again. On the other hand, if the EEM information notification unit 414 determines that the EEM information notification time has arrived (step S108: Yes), it generates EEM notification information, which includes wavelength spectrum information and excitation light wavelength information, stored in the EEM information storage unit 433. Then, the EEM information notification unit 414 transmits the generated EEM notification information to the external device 200 via the communication module 405 (step S109). After that, the process in step S101 is executed again.

[0029] Based on the EEM information obtained by the underwater fluorescence matrix measuring device 100 according to this embodiment, an analysis result image, such as the one shown in Figure 8, can be displayed on an external device 200. S1, S2, and S3 in Figure 8 are diagrams showing the wavelength spectra of fluorescence emitted from a measurement target when the measurement target is irradiated with excitation light with wavelengths of 435 nm, 470 nm, and 570 nm, respectively.

[0030] As described above, the underwater fluorescence matrix measuring device according to this embodiment comprises a housing 11 that houses five excitation light sources 21, 22, 23, 24, and 25, a light receiving unit 31, a spectroscopic unit 32, and a control unit 41, and a lid 12 fitted to the opening of the housing 11 so as to seal the inside of the housing 11. The lid 12 has five first through-holes 12c facing each of the five excitation light sources 21, 22, 23, and 24, and a second through-hole 12b facing the light receiving unit 31. The five first through-holes 12c are closed by a first optical member, and the second through-hole 12b is closed by a second optical member. As a result, even if the housing is left in water, water intrusion into the inside of the housing is prevented, so that continuous EEM spectroscopic measurements can be performed on objects present in the surrounding area while the housing is left in water.

[0031] Although embodiments of the present invention have been described above, the present invention is not limited to the configuration of the embodiments described above. It is not fixed. For example, the excitation light source may include a lens barrel that is bottomed and has an opening fixed to the lid 12, with at least one lens disposed inside; an optical transmission cable having an optical fiber, one end of which is positioned on the bottom wall side inside the lens barrel; and a light-emitting module that emits excitation light into the optical fiber from the other end of the optical transmission cable.

[0032] With this configuration, there is no need to place a light-emitting module inside the microscope tube, which allows for a smaller microscope tube and, consequently, a smaller underwater fluorescence matrix measurement device.

[0033] In the embodiment described, an example was given in which the spectroscopic element of the spectroscopic unit 32 is a so-called reflective concave grating. However, the embodiment is not limited to this, and the spectroscopic element may be a so-called transmission grating. In this case, the spectroscopic element is placed between the incident slit and the linear image sensor 323.

[0034] In this embodiment, the device may further include a cleaning unit (not shown) for periodically cleaning the first optical member 131 and the second optical member 132 attached to the lid 12. [Industrial applicability]

[0035] This invention is suitable for in-situ EEM spectroscopy analysis to elucidate the dynamics of dissolved organic matter (DOM) in water such as seas and rivers. [Explanation of symbols]

[0036] 11: Housing, 12: Cover, 12a: Recess, 12b: Second through-hole, 12c: First through-hole, 21, 22, 23, 24, 25: Excitation light source, 31: Light receiving unit, 32: Spectroscopic unit, 33: Optical transmission cable, 41: Control unit, 51: Battery, 100: Underwater fluorescence matrix measuring device, 131: First optical component, 132: Second optical component, 200: External equipment, 201: Lens tube, 202: Light emission module, 203: Lens, 321: Entrance slit T, 322: Spectroscopic element, 323: Linear image sensor, 324: Measurement information generation unit, 401: Processing unit, 402: Lighting circuit, 403: Interface, 404: Timing unit, 405: Communication module, 411: Excitation light source control unit, 412: Measurement information acquisition unit, 413: EEM information generation unit, 414: EEM information notification unit, 415: Setting acquisition unit, 421: Measurement information buffer, 431: Setting storage unit, 432: Wavelength information storage unit, 433: EEM information storage unit

Claims

1. Multiple excitation light sources that irradiate the object to be measured with excitation light in different wavelength bands to excite the object, A light receiving unit that receives fluorescence emitted from the object to be measured when the object to be measured is excited, A spectroscopic unit having a spectroscopic element that spectrally analyzes fluorescence received by the light receiving unit, and a plurality of light receiving elements arranged along the spectral direction of the spectroscopic element and that receive light spectrally analyzed by the spectroscopic element, An EEM (Excitation-Emission Matrix) information generation unit generates EEM information based on excitation wavelength information indicating the wavelength band of the excitation light when the object to be measured is sequentially irradiated with excitation light of different wavelength bands from the plurality of excitation light sources, and light reception intensity information indicating the intensity of the light received by each of the plurality of photoreceiving elements. A bottomed cylindrical housing containing the plurality of excitation light sources, the light receiving unit, the spectral unit, and the EEM information generation unit, The lid is fitted to the opening of the housing so as to seal the inside of the housing, and has a plurality of first through holes that penetrate from the inside to the outside of the housing and face each of the plurality of excitation light sources, and a second through hole that penetrates from the inside to the outside of the housing and faces the light receiving unit, the plurality of first through holes being closed by a first optical member that is transparent to the excitation light emitted from the plurality of excitation light sources, and the second through hole being closed by a second optical member that is transparent to the fluorescence emitted from the object to be measured that is present around the housing, Underwater fluorescence matrix measuring device.

2. The excitation light source control unit further comprises an excitation light source control unit that controls the lighting state of the plurality of excitation light sources, such that an irradiation duration for continuously irradiating each of the plurality of excitation light sources is set in advance, one of the plurality of excitation light sources is selected, the irradiation duration set for the selected excitation light source is identified, and the excitation light is repeatedly irradiated from the selected excitation light source to the object to be measured for the identified irradiation duration. The underwater fluorescence matrix measuring apparatus according to claim 1.

3. The irradiation duration for the plurality of excitation light sources is set such that the integrated amount of excitation light irradiated onto the object to be measured from the plurality of excitation light sources is equal. The underwater fluorescence matrix measuring apparatus according to claim 2.

4. Each of the aforementioned multiple excitation light sources emits excitation light whose wavelength corresponding to the intensity peak is one of 265 nm, 280 nm, 340 nm, 365 nm, and 405 nm. The underwater fluorescence matrix measuring apparatus according to any one of claims 1 to 3.

5. Each of the plurality of first through holes penetrates from inside the housing to outside the housing along the optical axis direction of each of the plurality of excitation light sources. The second through-hole extends from inside the housing to outside the housing along the optical axis direction of the light receiving unit. The underwater fluorescence matrix measuring apparatus according to any one of claims 1 to 3.

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