Measurement device measuring substance concentration of measured liquid

Abstract

To provide a device that, by enabling highly accurately and easily aligning a position of a light beam reflection unit with respect to a transparent part before and after a cleaning work of the light beam reflection unit to be arranged in a measured liquid, suppresses occurrence of measurement errors before and after the cleaning of the light beam reflection unit, enables making a stable concentration measurement over a long period, and measures substance concentration of the measured liquid.SOLUTION: A measurement device comprises: a transparent part that is provided in a wall surface of a container having a measured liquid accommodated; a light beam reflection unit that is arranged in the measured liquid; a light emitting unit that is arranged in a direction toward outside of the container with respect to the transparent part, and irradiates a visible light ray, infrared ray and / or ultraviolet ray toward the light beam reflection unit via the transparent part; and a light reception unit that is arranged in the direction toward outside of the container with respect to the transparent part, and receives the visible light ray, infrared ray and / or ultraviolet ray from the light beam reflection unit via the transparent part. The measurement device, in which the light beam reflection unit is attached to the transparent part, measures substance concentration of the measured liquid.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an apparatus for measuring the concentration of a substance in a liquid, and more specifically, to an apparatus for optically measuring the concentration of a substance in a liquid, which comprises a light reflecting unit placed in the liquid to be measured, an emitter and a receiver placed on the outside of a container. [Background technology]

[0002] An example of an optical device for measuring the concentration of a substance in a liquid is an optical device for measuring the concentration (number) of bacteria or cells in a culture solution for culturing microorganisms or animal or plant cells. Specifically, a turbidity measuring device has been proposed for measuring the turbidity of a culture solution from outside the culture tank, the device comprising a transparent part provided on the tank wall of the culture tank, a reflecting mirror disposed in the culture solution in the culture tank, a light emitting part disposed outside the culture tank and irradiating light toward the reflecting mirror through the transparent part, and a detection light receiving part disposed outside the culture tank and receiving light from the reflecting mirror direction through the transparent part (Patent Document 1).

[0003] Patent Document 1 claims that, compared to a case where a turbidity sensor is placed inside a culture tank, stable turbidity measurement is possible without damage to the turbidity sensor due to thermal heat cycles, and therefore the turbidity of the culture solution can be measured with high accuracy even from outside the culture tank. Patent Document 1 also claims that the bacterial concentration, cell concentration, etc. in the culture solution can be evaluated based on the measured turbidity of the culture solution, making it suitable for culture management, etc.

[0004] On the other hand, in Patent Document 1, a baffle plate (baffle plate) extending in the axial direction is provided near the inner circumference of the culture tank, and a reflecting mirror is attached to the baffle plate that is suspended and fixed to the top plate of the culture tank. Patent Document 1 also claims that by attaching the reflecting mirror to the baffle plate, measurement errors due to vibration or positional movement of the reflecting mirror can be prevented.

[0005] Since bacteria, cells, compounds, etc. in the liquid to be measured adhere to the light reflecting part disposed in the liquid to be measured such as a culture solution, the reflectance of the light reflecting part decreases over time. From the above, in order to accurately measure the concentration of a substance such as the turbidity of the liquid to be measured, it is necessary to periodically remove the light reflecting part from the support such as a baffle plate, wash the light reflecting part, and remove the bacteria, cells, compounds, etc. from the light reflecting part. In addition, in order to prevent measurement errors due to the positional movement of the light reflecting part, the washed light reflecting part needs to be attached to the container so as to accurately match the position of the light reflecting part in the liquid to be measured before washing. Specifically, before and after the washing operation of the light reflecting part, the incident angle of the light irradiated from the light emitting part to the light reflecting part and the distance from the transparent part to the light reflecting part need to accurately match in the liquid to be measured.

[0006] However, in Patent Document 1, a transparent portion is provided on the side wall of the culture tank, and a reflecting mirror is attached to a baffle plate fixed to the top plate of the culture tank. That is, in Patent Document 1, the reflecting mirror is attached to a member separate from the transparent portion, which is provided at a position spatially separated from the transparent portion, and therefore there is a problem in that it is difficult to attach the cleaned reflecting mirror in a manner that precisely matches the position of the reflecting mirror before cleaning.

[0007] If the position of the reflector relative to the transparent part is not precisely aligned before and after cleaning of the reflector, measurement errors will occur before and after cleaning of the reflector, making it impossible to perform stable turbidity measurements over a long period of time. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] International Publication No. 2012 / 127650 Summary of the Invention [Problem to be solved by the invention]

[0009] In view of the above circumstances, the present invention aims to provide an apparatus for measuring the concentration of a substance in a liquid to be measured, which can easily and accurately align the position of a light reflecting part relative to a transparent part before and after cleaning of the light reflecting part placed in the liquid to be measured, thereby suppressing the occurrence of measurement errors before and after cleaning of the light reflecting part and enabling stable concentration measurements over a long period of time. [Means for solving the problem]

[0010] The gist of the configuration of the measuring device of the present invention for measuring the concentration of a substance in a test liquid is as follows. [1] A transparent portion provided on the wall of a container containing the liquid to be measured; a light reflecting portion disposed in the liquid to be measured; a light emitting section that is disposed on the outer side of the container from the transparent section and irradiates visible light, infrared light, and / or ultraviolet light toward the light reflecting section through the transparent section; a light receiving section that is disposed outside the container with respect to the transparent section and receives visible light, infrared light, and / or ultraviolet light that is reflected from the light reflecting section through the transparent section; A measuring device for measuring a substance concentration in a liquid to be measured, wherein the light reflecting portion is attached to the transparent portion. [2] The measuring device according to [1], wherein the light reflecting portion is attached to the transparent portion by a light reflecting portion fixing member having one end connected to the light reflecting portion and the other end connected to the transparent portion. [3] The measuring device according to [2], wherein the light reflecting portion fixing member is a rod-shaped member. [4] The measuring device according to any one of [1] to [3], wherein the light reflecting portion is removably attached to the transparent portion. [5] The measuring device according to any one of [1] to [3], wherein the angle of incidence of the visible light, infrared light and / or ultraviolet light to the light reflecting portion is in the range of 0° or more and 30° or less. [6] The measuring device according to any one of [1] to [3], wherein the angle of incidence of the visible light, infrared light and / or ultraviolet light to the light reflecting portion is in the range of 0° or more and 5° or less. [7] The measuring device according to any one of [1] to [3], wherein the extension direction of the light reflecting portion is parallel to the extension direction of the transparent portion. [8] The measuring device according to any one of [1] to [3], wherein the extension direction of the light reflecting portion is not parallel to the extension direction of the transparent portion. [9] The measuring device according to any one of [1] to [3], wherein the container is a culture tank, a liquid mixing tank for mixing a first substance and a second substance in a liquid, or a reaction tank for reacting a first substance and a second substance in a liquid. Effect of the Invention

[0011] According to the aspect of the measuring device for measuring the substance concentration of the liquid to be measured of the present invention, the light reflecting part disposed in the liquid to be measured is attached to a transparent part provided on the wall surface of the container in which the liquid to be measured is contained, so that the position of the light reflecting part relative to the transparent part can be accurately and easily matched before and after the cleaning operation of the light reflecting part disposed in the liquid to be measured. That is, since the light reflecting part is attached to the transparent part, when the light reflecting part is removed from the container and cleaned, and then the cleaned light reflecting part is attached to the container again, the position of the light reflecting part relative to the transparent part can be accurately and easily matched before and after the cleaning operation of the light reflecting part. Therefore, according to the aspect of the measuring device for measuring the substance concentration of the liquid to be measured of the present invention, the occurrence of measurement errors of the substance concentration before and after the cleaning of the light reflecting part is suppressed, the measurement accuracy of the substance concentration is improved, and stable concentration measurement can be performed for a long period of time.

[0012] According to an aspect of the measuring device of the present invention for measuring the concentration of a substance in a liquid to be measured, the light reflecting portion is attached to the transparent portion by a light reflecting portion fixing member having one end connected to the light reflecting portion and the other end connected to the transparent portion, thereby facilitating the operation of removing the dirty light reflecting portion from the container and the operation of reattaching the cleaned light reflecting portion to the container.

[0013] According to the aspect of the measuring device for measuring the substance concentration of the liquid to be measured of the present invention, since the light reflecting unit fixing member is a rod-shaped member, the liquid to be measured can smoothly flow between the light reflecting unit and the transparent unit, so that the occurrence of measurement errors in the concentration of the substance can be more reliably suppressed. Also, since the light reflecting unit fixing member is a rod-shaped member, the operation of removing the dirty light reflecting unit from the container and the operation of reattaching the cleaned light reflecting unit to the container can be more smoothly performed.

[0014] According to an embodiment of the measuring device of the present invention for measuring the substance concentration of a liquid to be measured, the angle of incidence of visible light, infrared light and / or ultraviolet light to the light reflecting portion is in the range of 0° or more and 30° or less, thereby improving the measurement accuracy of the substance concentration.

[0015] According to an embodiment of the measuring device of the present invention for measuring the substance concentration of a liquid to be measured, the angle of incidence of visible light, infrared light and / or ultraviolet light to the light reflecting portion is in the range of 0° or more and 5° or less, thereby further improving the measurement accuracy of the substance concentration. [Brief description of the drawings]

[0016] [Figure 1] 1 is an overall perspective view of a measurement device for measuring a substance concentration in a test liquid according to an embodiment of the present invention; [Diagram 2] 1 is an enlarged plan view of a transparent portion and a light reflecting portion of a measurement device for measuring a substance concentration in a sample liquid according to an embodiment of the present invention. [Diagram 3] 1 is an explanatory diagram showing a first positional relationship between a transparent portion and a light reflecting portion of a measurement device for measuring a substance concentration in a sample liquid according to an embodiment of the present invention. FIG. [Figure 4] 11 is an explanatory diagram showing a second positional relationship between a transparent portion and a light reflecting portion of a measurement device for measuring a substance concentration in a sample liquid according to an embodiment of the present invention. FIG. [Diagram 5] 1 shows spectra showing the relationship between wavelength and absorbance obtained using the measuring devices of Example 1, Example 2, and Comparative Example 1. [Figure 6] 13 is a graph showing the relationship between the predicted measured concentration and the set concentration in Example 3. [Figure 7] 1 shows spectra showing the relationship between wavelength and absorbance obtained using the measuring devices of Example 4, Example 5, and Comparative Example 2. [Figure 8] 13 is a graph showing the relationship between predicted absorbance values ​​and actual absorbance values ​​in Example 6. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] A measurement device for measuring a substance concentration in a test liquid according to an embodiment of the present invention will be described below. Fig. 1 is an overall perspective view of a measurement device for measuring a substance concentration in a test liquid according to an embodiment of the present invention. Fig. 2 is an enlarged plan view of a transparent part and a light reflecting part of a measurement device for measuring a substance concentration in a test liquid according to an embodiment of the present invention.

[0018] 1 and 2, a measurement device (hereinafter, sometimes simply referred to as a "measurement device") 10 for measuring a substance concentration in a test liquid according to an embodiment of the present invention includes a container 5 that contains a test liquid 100, the substance concentration of which is to be measured by the measurement device 10, and a measurement unit 20 that is provided on a wall surface of the container 5 and that measures the substance concentration of the test liquid 100. In the measurement device 10, the measurement unit 20 is provided in a partial area of ​​a peripheral wall surface 51 of the wall surface of the container 5.

[0019] The measurement section 20 has a transparent section 2 provided on the wall surface of the container 5 in which the test liquid 100 is contained, and a light reflecting section 3 disposed in the test liquid 100. The transparent section 2 is a transparent section, and is provided on approximately the same plane as the peripheral wall surface 51. The light reflecting section 3 is disposed on the inner side of the container 5 relative to the transparent section 2. The light reflecting section 3 is immersed in the test liquid 100. The light reflecting section 3 is disposed opposite the transparent section 2 with a predetermined gap S interposed therebetween. The test liquid 100 contained in the container 5 flows into the gap S.

[0020] Furthermore, the measuring device 10 includes a light-emitting unit 6 that is disposed on the outer side of the container 5 relative to the transparent unit 2 and that irradiates visible light, infrared light, and / or ultraviolet light toward the light reflecting unit 3 via the transparent unit 2, and a light-receiving unit 7 that is disposed on the outer side of the container 5 relative to the transparent unit 2 and that receives the visible light, infrared light, and / or ultraviolet light that is reflected from the light reflecting unit 3 via the transparent unit 2. In the measuring device 10, both the light-emitting unit 6 and the light-receiving unit 7 are housed inside a housing 61. Therefore, in the measuring device 10, the light-emitting unit 6 and the light-receiving unit 7 are integrated into one by the housing 61 and disposed in substantially the same position.

[0021] Moreover, the light emitting section 6 and the light receiving section 7, which are arranged at approximately the same position, are both arranged facing the light reflecting section 3.

[0022] As described above, in the measuring device 10, a light reflecting unit 3 is disposed inside the container 5, and a light emitting unit 6 that irradiates visible light, infrared light, and / or ultraviolet light toward the light reflecting unit 3, and a light receiving unit 7 that receives the visible light, infrared light, and / or ultraviolet light that is reflected from the light reflecting unit 3 are disposed outside the container 5. In addition, since the light emitting unit 6 and the light receiving unit 7 are disposed at approximately the same position toward the light reflecting unit 3, the light receiving unit 7 can receive the reflected light from the light reflecting unit 3 that is caused by the irradiation light (visible light, infrared light, and / or ultraviolet light) irradiated from the light emitting unit 6.

[0023] In the measuring device 10, visible light, infrared light and / or ultraviolet light are irradiated from the light emitting unit 6 to the test liquid 100 flowing into the gap S through the transparent unit 2 provided on the wall surface (circumferential wall surface 51) of the container 5, and the visible light, infrared light and / or ultraviolet light transmitted through the test liquid 100 in the gap S from the light emitting unit 6 toward the light reflecting unit 3 is reflected by the reflection function of the light reflecting unit 3, and the visible light, infrared light and / or ultraviolet light reflected from the light reflecting unit 3 transmits through the test liquid 100 in the gap S from the light reflecting unit 3 toward the light receiving unit 7 and is received by the light receiving unit 7 through the transparent unit 2. Therefore, the light receiving unit 7 receives the transmitted light transmitted through the test liquid 100 in the gap S.

[0024] As described above, the measuring device 10 is a transmitted light measurement type device in which a light reflecting unit 3 is arranged inside a container 5 containing the measured liquid 100, and a light emitting unit 6 and a light receiving unit 7 are arranged at approximately the same position outside the container 5, thereby measuring the substance concentration of the measured liquid 100 from outside the container 5.

[0025] In the measuring device 10, when the reflected light from the light reflecting unit 3 caused by the irradiated light from the light emitting unit 6, i.e., the transmitted light transmitted through the measurement liquid 100 in the gap S, is received by the light receiving unit 7, the transmitted light decreases and the absorbance increases as the substance concentration of the measurement liquid 100 increases. On the other hand, the transmitted light increases and the absorbance decreases as the substance concentration of the measurement liquid 100 decreases. Therefore, the substance concentration of the measurement liquid 100 can be measured by measuring the absorbance of the reflected light from the light reflecting unit 3 by the light receiving unit 7. In addition, the substance concentration of the measurement liquid 100 can be continuously measured by continuously measuring the absorbance of the reflected light from the light reflecting unit 3 by the light receiving unit 7. By continuously measuring the substance concentration of the measurement liquid 100, the change in the substance concentration of the measurement liquid 100 can be grasped, and the substance concentration of the measurement liquid 100 can be managed over time. As described above, the measurement device 10 measures the substance concentration of the test liquid 100 flowing into the space S.

[0026] The container 5 is a member for containing the test liquid 100, in which the test liquid 100 is stored, retained, circulated, etc. The material, size, shape, etc. of the container 5 can be appropriately selected depending on the conditions of use of the container 5, etc. The material of the container 5 is not particularly limited, and examples thereof include metal, glass, resin, etc. Note that, in the measurement device 10, the material of the container 5 is metal or resin. The size of the container 5 is not particularly limited, and examples thereof include 100 mL or more and 100,000 L or less. The shape of the container 5 is not particularly limited, and examples thereof include a cylindrical shape, a prismatic shape, etc. Note that, in the measurement device 10, the container 5 is cylindrical in shape.

[0027] The transparent portion 2 is a transparent portion provided on the wall surface (peripheral wall surface 51 in the measuring device 10) of the container 5. The transparent portion 2 is attached to a measuring unit attachment portion 1 formed on a partial area of ​​the wall surface (peripheral wall surface 51) of the container 5 (peripheral wall surface 51 in the measuring device 10). The measuring unit attachment portion 1 has a housing portion 11 that houses the measuring unit 20, and a cover portion 12 that is a transparent member that covers the transparent portion 2 of the measuring unit 20. The measuring unit 20 is housed in the measuring unit attachment portion 1 by being housed in a state where the measuring unit 20 is fitted into a hole portion 14 formed in the housing portion 11. In the measuring device 10, the cover portion 12 is fixed to the housing portion 11 by screws 13.

[0028] The material of the storage unit 11 is not particularly limited, and may be, for example, the same material as the container 5, and specific examples thereof include metal, glass, resin, etc. In the measuring device 10, the material of the storage unit 11 is metal or resin. The material of the cover unit 12 is not particularly limited, and may be, for example, the same material as the transparent unit 2 described below, and specific examples thereof include glass, polypropylene, transparent resin such as polycarbonate, etc.

[0029] The wall surface of the container 5 is a portion that forms the outer shape of the container 5. The transparent portion 2 transmits visible light, infrared light, and / or ultraviolet light irradiated from the light emitting portion 6, and also transmits visible light, infrared light, and / or ultraviolet light that is reflected from the light reflecting portion 3. When the material of the wall surface of the container 5 is a transparent member such as glass, the wall surface of the container 5 itself functions as the transparent portion 2, but when the material of the wall surface of the container 5 is a non-transparent member such as metal, colored resin, etc., a separate transparent portion 2 is provided in a partial area of ​​the wall surface of the container 5.

[0030] The material of the transparent part 2 is not particularly limited as long as it is a transparent member, and examples thereof include glass, transparent resins such as polypropylene and polycarbonate. In the measuring device 10, the transparent part 2, which is a transparent member, is provided separately in a partial region of the wall surface of the container 5.

[0031] As shown in FIGS. 1 and 2, in the measuring device 10, a light reflecting section 3 is provided inside a container 5 and near a transparent section 2. The light reflecting section 3 is disposed opposite the transparent section 2 via a gap S, which is a partial area inside the container 5. That is, the gap S is formed between the reflecting surface of the light reflecting section 3 and the inner surface of the transparent section 2. The liquid to be measured 100 contained in the container 5 flows into the gap S, and the gap S is filled with the liquid to be measured 100. Therefore, the light reflecting section 3 and the inner surface of the transparent section 2 are immersed in the liquid to be measured 100.

[0032] Examples of the material of the light reflecting part 3 include metal, glass, resin, etc., and specifically, materials in which a metal film of silver, aluminum, etc. is coated on a substrate such as glass or resin, etc., can be mentioned. The shape of the reflection surface of the light reflecting part 3 can be appropriately selected depending on the use conditions of the measurement device 10, etc., and examples of the shape include a flat surface, a concave surface, a convex surface, etc. The size of the reflection surface of the light reflecting part 3 can be appropriately selected depending on the use conditions of the measurement device 10, etc., and examples of the shape include a circle with a diameter of 10 mm to 100 mm, a rectangle with one side of 10 mm to 100 mm, etc.

[0033] 1 and 2, in the measuring device 10, the light reflecting portion 3 is attached to the transparent portion 2. By attaching the light reflecting portion 3 to the transparent portion 2, the light reflecting portion 3 and the transparent portion 2 are integrated together. In other words, a gap S is formed between the light reflecting portion 3 and the transparent portion 2, which are integrated together.

[0034] In the measuring device 10, the light reflecting part 3 arranged in the liquid to be measured 100 is attached to the transparent part 2 provided on the wall surface of the container 5 in which the liquid to be measured 100 is contained, so that the position of the light reflecting part 3 relative to the transparent part 2 can be accurately and easily matched before and after the cleaning operation of the light reflecting part 3 arranged in the liquid to be measured 100. That is, since the light reflecting part 3 is attached to the transparent part 2, when the light reflecting part 3 is removed from the container 5 and cleaned, and then the cleaned light reflecting part 3 is attached to the container 5 again, the position of the light reflecting part 3 relative to the transparent part 3 can be accurately and easily matched before and after the cleaning operation of the light reflecting part 3. Therefore, in the measuring device 10, the occurrence of measurement errors in the substance concentration of the liquid to be measured 100 before and after the cleaning of the light reflecting part 3 is suppressed, the measurement accuracy of the substance concentration is improved, and stable concentration measurement can be performed over a long period of time.

[0035] In the measuring device 10, the light reflecting portion 3 is attached to the transparent portion 2 by the light reflecting portion fixing member 4. The light reflecting portion fixing member 4 has one end 41 connected to the light reflecting portion 3 and the other end 42 connected to the transparent portion 2, and the one end 41 is located toward the inside of the container 5 from the other end 42. One end 41 of the light reflecting portion fixing member 4 is connected to the light reflecting portion 3, and the other end 42 of the light reflecting portion fixing member 4 is connected to the transparent portion 2, so that the light reflecting portion 3 is attached to the transparent portion 2 while a gap S is formed between the reflection surface of the light reflecting portion 3 and the inner surface of the transparent portion 2. In this way, the other end 42 of the light reflecting portion fixing member 4 is supported by the transparent portion 2, and the light reflecting portion 3 is supported by the one end 41 of the light reflecting portion fixing member 4, so that the light reflecting portion 3 is fixed and supported to the transparent portion 2 via the light reflecting portion fixing member 4.

[0036] Since the light reflecting portion 3 is attached to the transparent portion 2 by the light reflecting portion fixing member 4, which has one end 41 connected to the light reflecting portion 3 and the other end 42 connected to the transparent portion 2, the assembly structure of the light reflecting portion 3 and the transparent portion 2 via the light reflecting portion fixing member 4 is simplified, thereby facilitating the work of removing the dirty light reflecting portion 3 from the container 5 and the work of reattaching the cleaned light reflecting portion 3 to the container 5.

[0037] In the measurement device 10, the light reflecting unit fixing member 4 is a rod-shaped member. Therefore, in the measurement device 10, the test liquid 100 can smoothly flow between the light reflecting unit 3 and the transparent unit 2, so that the occurrence of measurement errors in the substance concentration of the test liquid 100 can be more reliably suppressed. In addition, because the light reflecting unit fixing member 4 is a rod-shaped member, the operation of removing the dirty light reflecting unit 3 from the container 5 and the operation of reattaching the cleaned light reflecting unit 3 to the container 5 can be more smoothly performed.

[0038] The material of the light reflector fixing member 4 is not particularly limited, and examples thereof include metal, glass, and resin. The length of the light reflector fixing member 4 along the inner direction of the container 5 can be appropriately selected depending on the conditions of use of the measuring device 10, and examples thereof include a length such that the dimension of the gap S along the inner direction of the container 5 is 1 mm or more and 100 mm or less, and preferably 5 mm or more and 50 mm or less. When the dimension of the gap S along the inner direction of the container 5 is the above-mentioned length, the attenuation of light passing through the measured liquid 100 in the gap S can be optimized.

[0039] A connection portion (not shown) of the light reflecting portion fixing member 4 is provided on the edge of the light reflecting portion 3, and one end 41 of the light reflecting portion fixing member 4 is attached to the connection portion of the light reflecting portion 3. The manner in which the one end 41 of the light reflecting portion fixing member 4 is attached to the connection portion is not particularly limited, and examples thereof include a manner in which the one end 41 of the light reflecting portion fixing member 4 is fitted into a hole portion of the connection portion, a manner in which the one end 41 of the light reflecting portion fixing member 4 is screwed (screwed) into a hole portion of the connection portion, and a manner in which the one end 41 of the light reflecting portion fixing member 4 is detachably attached to the connection portion of the light reflecting portion 3. In addition, a pedestal 4a is provided on the edge of the transparent portion 2, and the other end 42 of the light reflecting portion fixing member 4 is attached to the pedestal 4a. In addition, the pedestal 4a is located on the periphery of the hole portion 14 formed in the storage portion 11. The manner in which the other end 42 of the light reflecting unit fixing member 4 is attached to the base 4a is not particularly limited, and examples thereof include a manner in which the other end 42 of the light reflecting unit fixing member 4 is fitted into a hole in the base 4a, a manner in which the other end 42 of the light reflecting unit fixing member 4 is screwed into a hole in the base 4a, or a manner in which the other end 42 of the light reflecting unit fixing member 4 is detachably attached to the base 4a.

[0040] As described above, the light reflecting portion 3 is attached to the transparent portion 2 in a detachable manner.

[0041] As shown in Figures 1 and 2, in the measuring device 10, a light-emitting unit 6 and a light-receiving unit 7 are arranged outside the transparent unit 2, i.e., outside the wall surface of the container 5, facing the transparent unit 2. The light-emitting unit 6 and the light-receiving unit 7 are integrated into one by a housing 61 and arranged in approximately the same position, so that the light irradiated from the light-emitting unit 6 outside the transparent unit 2 is reflected by the light-reflecting unit 3 and received by the light-receiving unit 7 also outside the transparent unit 2, thereby making it possible to measure the substance concentration of the measured liquid 100 from outside the container 5 by a transmitted light measurement method. The light-emitting unit 6 and the light-receiving unit 7 are arranged so that the optical axis of the light irradiated from the light-emitting unit 6 to the light-reflecting unit 3 and the optical axis of the reflected light (transmitted light) from the light-reflecting unit 3 to the light-receiving unit 7 are included in the same plane.

[0042] The light-emitting unit 6 and the light-receiving unit 7 are positioned relative to the measurement unit 20 by being inserted into an insertion unit 15 , which is a hole provided in the outer surface of the cover unit 12 .

[0043] Examples of the light emitted from the light emitting section 6 include visible light having a wavelength of 380 nm to 780 nm, infrared light such as near infrared light having a wavelength of 780 nm to 3 μm, and ultraviolet light such as near ultraviolet light having a wavelength of 200 nm to 380 nm.

[0044] The light source of the light emitting unit 6 may be a known light source, such as a light emitting diode or a laser.

[0045] A known device can be used as the light receiving section 7, and examples of such devices include a photodiode, a photocell, etc. The light emitting section 6 and the light receiving section 7 may be of an integrated type or of a separate type.

[0046] Next, the positional relationship between the light emitting unit 6, the transparent unit 2, and the light reflecting unit 3 will be described. Fig. 3 is an explanatory diagram showing a first positional relationship between the transparent unit and the light reflecting unit of a measurement device for measuring a substance concentration in a sample liquid according to an embodiment of the present invention. Fig. 4 is an explanatory diagram showing a second positional relationship between the transparent unit and the light reflecting unit of a measurement device for measuring a substance concentration in a sample liquid according to an embodiment of the present invention.

[0047] The angle of the reflective surface of the light reflecting unit 3 is not particularly limited as long as it is an angle at which the transmitted light irradiated from the light emitting unit 6 can be measured, but it is preferable that the reflective surface of the light reflecting unit 3 faces the inner surface of the transparent unit 2 and is positioned at an angle at which the irradiated light from the light emitting unit 6 can be efficiently reflected to the light receiving unit 7.

[0048] Specifically, for example, as shown in Figures 3 and 4, in order to improve the measurement accuracy of the substance concentration of the measured liquid 100, it is preferable to set the angle of the reflecting surface of the light reflecting unit 3 so that the angle of incidence of the irradiation light (visible light, infrared light and / or ultraviolet light) L irradiated from the light-emitting unit 6 to the light reflecting unit 3 is in the range of 0° or more and 30° or less, and in order to further improve the measurement accuracy of the substance concentration of the measured liquid 100, it is particularly preferable to set the angle of the reflecting surface of the light reflecting unit 3 so that the angle of incidence of the irradiation light (visible light, infrared light and / or ultraviolet light) L irradiated from the light-emitting unit 6 to the light reflecting unit 3 is in the range of 0° or more and 5° or less.

[0049] 3 shows a first positional relationship between the transparent portion 2 and the light reflecting portion 3, in which the angle of incidence of the irradiation light L emitted from the light emitting portion 6 on the light reflecting portion 3 is in the range of 0° to 5°, for example, the angle of incidence of the irradiation light L emitted from the light emitting portion 6 on the light reflecting portion 3 is 0°. In the first positional relationship, since the angle of incidence of the irradiation light L emitted from the light emitting portion 6 on the transparent portion 2 is about 10° to 15°, the extension direction of the light reflecting portion 3 is not parallel to the extension direction of the transparent portion 2, but is inclined by about 10° to 15° with respect to the extension direction of the transparent portion 2.

[0050] Alternatively, the first positional relationship may be such that the angle of incidence of the irradiation light L emitted from the light-emitting unit 6 on the transparent unit 2 is in the range of 0° or more and 5° or less, for example, the angle of incidence of the irradiation light L emitted from the light-emitting unit 6 on the transparent unit 2 is 0°, and the angle of incidence of the irradiation light L emitted from the light-emitting unit 6 on the light reflecting unit 3 is in the range of 0° or more and 5° or less, for example, the angle of incidence of the irradiation light L emitted from the light-emitting unit 6 on the light reflecting unit 3 is 0°. In this case, the extension direction of the light reflecting unit 3 is approximately parallel to the extension direction of the transparent unit 2.

[0051] 4 shows a second positional relationship between the transparent section 2 and the light reflecting section 3, in which the angle of incidence of the irradiation light L emitted from the light emitting section 6 on the light reflecting section 3 is in the range of 0° to 30°, for example, the angle of incidence of the irradiation light L emitted from the light emitting section 6 on the light reflecting section 3 is 10° to 15°. In the second positional relationship, the angle of incidence of the irradiation light L emitted from the light emitting section 6 on the transparent section 2 is about 10° to 15°, so that the extension direction of the light reflecting section 3 is approximately parallel to the extension direction of the transparent section 2.

[0052] Alternatively, the second positional relationship may be such that the angle of incidence of the irradiation light L emitted from the light-emitting unit 6 on the transparent unit 2 is in the range of 0° to 5°, for example, the angle of incidence of the irradiation light L emitted from the light-emitting unit 6 on the transparent unit 2 is 0°, and the angle of incidence of the irradiation light L emitted from the light-emitting unit 6 on the light reflecting unit 3 is in the range of 0° to 30°, for example, the angle of incidence of the irradiation light L emitted from the light-emitting unit 6 on the light reflecting unit 3 is 10° to 15°. In this case, the extension direction of the light reflecting unit 3 is not parallel to the extension direction of the transparent unit 2, but is tilted by 10° to 15° with respect to the extension direction of the transparent unit 2.

[0053] The function of the container 5 is not particularly limited, and examples thereof include a culture tank for culturing bacteria or cells, a liquid mixing tank for mixing a first substance and a second substance in a liquid, and a reaction tank for reacting a first substance and a second substance in a liquid. When the container 5 is a culture tank, the measuring device 10 can measure the number (concentration) of bacteria or cells in the liquid 100 to be measured and the growth degree of bacteria or cells in the liquid 100 to be measured. When the container 5 is a liquid mixing tank, the measuring device 10 can measure the degree of mixing of the first substance and the second substance in the liquid 100 to be measured. When the container 5 is a reaction tank, the measuring device 10 can measure the amount of a reaction product (concentration of the reaction product) of the first substance and the second substance in the liquid 100 to be measured.

[0054] Next, another embodiment of the measuring device of the present invention will be described. In the measuring device 10 according to the embodiment of the present invention, the measuring unit 20 having the transparent portion 2 is provided on the peripheral wall surface 51 among the wall surfaces of the container 5, but instead of this, the measuring unit 20 having the transparent portion 2 may be provided on the bottom wall surface. Also, in the measuring device 10 according to the embodiment of the present invention, the light reflecting unit fixing member 4 is a rod-shaped member, but instead of this, it may be a plate-shaped member or a mesh-shaped member. EXAMPLES

[0055] Next, examples of the present invention will be described, but the present invention is not limited to these examples as long as they do not depart from the spirit of the present invention.

[0056] Example 1 The measuring device 10 for measuring the substance concentration of the liquid to be measured according to the embodiment of the present invention described above was used as the measuring device for measuring the substance concentration of the liquid to be measured. The positional relationship between the transparent part and the light reflecting part was set to the first positional relationship, in which the angle of incidence of the light irradiated from the light emitting part to the light reflecting part was 0°, and the angle of incidence of the light irradiated from the light emitting part to the transparent part was 10°. An aqueous ethanol solution was used as the liquid to be measured, and near infrared rays with wavelengths in the range of 900 nm to 1700 nm were used as the light irradiated from the light emitting part, to obtain a spectrum in which the x-axis is the wavelength and the y-axis is the absorbance.

[0057] Example 2 A spectrum was obtained in the same manner as in Example 1, with the x-axis representing wavelength and the y-axis representing absorbance, except that the angle of incidence of the light irradiated from the light-emitting unit to the light reflecting unit was changed from 0° to 10°, and the angle of incidence of the light irradiated from the light-emitting unit to the transparent unit was changed to a second positional relationship, with the angle of incidence of the light irradiated from the light-emitting unit to the light reflecting unit being 10° and the angle of incidence of the light irradiated from the light-emitting unit to the transparent unit being 10°.

[0058] Comparative Example 1 A spectrum with wavelength on the x-axis and absorbance on the y-axis was obtained in the same manner as in Example 1, except that a measuring device without a light reflecting section was used as the measuring device for measuring the substance concentration of the test liquid.

[0059] FIG. 5 shows spectra showing the relationship between wavelength and absorbance obtained using the measuring devices of Example 1, Example 2, and Comparative Example 1.

[0060] 5, in Examples 1 and 2 using the measuring device of the present invention, the absorbance was significantly increased in the near infrared ray wavelength range of 1400 nm to 1700 nm compared to Comparative Example 1, and it was found that the measurement accuracy of the substance concentration (ethanol concentration) in the measured liquid was improved. In particular, in Example 1 in which the incident angle of the irradiated light irradiated from the light emitting unit to the light reflecting unit is 0°, the absorbance was further increased in the near infrared ray wavelength range of 1400 nm to 1700 nm compared to Example 2 in which the incident angle of the irradiated light irradiated from the light emitting unit to the light reflecting unit is 10°, and it was found that the measurement accuracy of the substance concentration in the measured liquid was further improved.

[0061] Furthermore, in Examples 1 and 2, there was no significant change in the spectrum showing the relationship between wavelength and absorbance before and after cleaning of the light reflecting part, and the occurrence of measurement errors in the concentration of substances was suppressed, which demonstrated that the position of the light reflecting part relative to the transparent part can be matched with high precision.

[0062] In addition, using the spectra showing the relationship between wavelength and absorbance obtained by the measuring devices of Example 1, Example 2, and Comparative Example 1, a multivariate analysis was performed using partial least squares regression (PLS) to obtain a predicted measured concentration of the substance in the measured solution from the spectrum, and the deviation from the set concentration (actual concentration) of the substance in the measured solution was calculated.

[0063] The predicted measured concentration, the set concentration, and the deviation between the predicted measured concentration and the set concentration in the measuring devices of Example 1, Example 2, and Comparative Example 1 are shown in Table 1 below.

[0064] [Table 1]

[0065] As shown in Table 1 above, it was found that in Examples 1 and 2 using the measurement device of the present invention, the deviation between the predicted measurement concentration and the set concentration was reduced, and the measurement accuracy of the substance concentration in the measurement liquid was improved, compared to Comparative Example 1. In particular, it was found that in Example 1, in which the incident angle of the irradiation light irradiated from the light emitting unit to the light reflecting unit is 0°, the deviation between the predicted measurement concentration and the set concentration was reduced, and the measurement accuracy of the substance concentration in the measurement liquid was further improved, compared to Example 2, in which the incident angle of the irradiation light irradiated from the light emitting unit to the light reflecting unit is 10°.

[0066] Example 3 As a measuring device for measuring the substance concentration of the liquid to be measured, the measuring device 10 for measuring the substance concentration of the liquid to be measured according to the embodiment of the present invention described above was used, as in Example 1. As in Example 1, the positional relationship between the transparent part and the light reflecting part was the first positional relationship, in which the angle of incidence of the light irradiated from the light emitting part to the light reflecting part was 0°, and the angle of incidence of the light irradiated from the light emitting part to the transparent part was 10°. An ethanol aqueous solution (substance concentration (ethanol concentration) in the liquid to be measured: 0 mass%, 25 mass%, 50 mass%, 75 mass%, 100 mass%) was used as the liquid to be measured, and near infrared rays with wavelengths in the range of 900 nm to 1700 nm were used as the light irradiated from the light emitting part to obtain a spectrum with wavelength on the x axis and absorbance on the y axis, and a multivariate analysis was performed by partial least squares regression (PLS) using the obtained spectrum to obtain a predicted measured concentration of the substance in the liquid to be measured from the spectrum. Five spectral measurements (n=5) were performed for the substance concentration in each liquid to be measured. In Example 3, the light reflecting portion was detached each time the concentration of the substance in the liquid to be measured was changed.

[0067] FIG. 6 is a graph showing the relationship between the predicted measured concentration and the set concentration in Example 3, with the set concentration on the x-axis and the predicted measured concentration on the y-axis.

[0068] Furthermore, the set concentrations and the average predicted measured concentrations (n=5) at each set concentration in Example 3 are shown in Table 2 below.

[0069] [Table 2]

[0070] 6 and Table 2 above, it was found that in Example 3, in which the measuring device of the present invention was used and the positional relationship between the transparent part and the light reflecting part was the first positional relationship, the difference between the predicted measured concentration and the set concentration was small, and the difference in the predicted measured concentration when n = 5 was also small, improving the measurement accuracy of the substance concentration in the measured liquid. Furthermore, in Example 3, it was found that the occurrence of measurement errors in the substance concentration could be suppressed even when the light reflecting part was detached, and therefore the position of the light reflecting part relative to the transparent part could be matched with high precision.

[0071] Example 4 A spectrum was obtained in the same manner as in Example 1, with the x-axis representing wavelength and the y-axis representing absorbance, except that a diluted solution of bacteria was used as the measurement liquid instead of the aqueous ethanol solution.

[0072] Example 5 A spectrum was obtained in the same manner as in Example 2, with the x-axis representing wavelength and the y-axis representing absorbance, except that a diluted solution of bacteria was used as the measurement liquid instead of the aqueous ethanol solution.

[0073] Comparative Example 2 A spectrum with wavelength on the x-axis and absorbance on the y-axis was obtained in the same manner as in Example 4, except that a measuring device without a light reflecting section was used as the measuring device for measuring the substance concentration of the test liquid.

[0074] FIG. 7 shows spectra showing the relationship between wavelength and absorbance obtained using the measuring devices of Example 4, Example 5, and Comparative Example 2.

[0075] 7, in Examples 4 and 5 using the measuring device of the present invention, the absorbance was significantly increased in the near infrared wavelength range of 1400 nm to 1700 nm compared to Comparative Example 2, and it was found that the measurement accuracy of the substance concentration (bacterial cell concentration) in the measured liquid was improved. In particular, it was found that in Example 4, in which the incident angle of the irradiated light irradiated from the light emitting unit to the light reflecting unit is 0°, the absorbance was stabilized in the near infrared wavelength range of 1400 nm to 1700 nm compared to Example 5, in which the incident angle of the irradiated light irradiated from the light emitting unit to the light reflecting unit is 10°, and the measurement accuracy of the substance concentration in the measured liquid was further improved.

[0076] Furthermore, in Examples 4 and 5, there was no significant change in the spectrum showing the relationship between wavelength and absorbance before and after cleaning of the light reflecting part, and the occurrence of measurement errors in the concentration of substances was suppressed, which demonstrated that the position of the light reflecting part relative to the transparent part can be matched with high precision.

[0077] Example 6 As a measuring device for measuring the substance concentration of a liquid to be measured, the measuring device 10 for measuring the substance concentration of a liquid to be measured according to the embodiment of the present invention described above was used, as in Examples 1 and 4. As in Examples 1 and 4, the positional relationship between the transparent part and the light reflecting part was the first positional relationship, in which the angle of incidence of the light irradiated from the light emitting part to the light reflecting part was 0°, and the angle of incidence of the light irradiated from the light emitting part to the transparent part was 10°. A diluted solution of bacteria was used as the liquid to be measured, and the actual substance concentration (bacterial concentration) in the liquid to be measured was the actual absorbance measured at a wavelength of 600 nm (actual absorbance measured values: 0.001, 0.012, 0.033, 0.048, 0.070). Near infrared rays with wavelengths ranging from 900 nm to 1700 nm were used as the irradiating light for the light emitting part, and a spectrum with wavelength on the x-axis and absorbance on the y-axis was obtained. Using the obtained spectrum, a multivariate analysis was performed by partial least squares regression (PLS) to obtain a predicted absorbance value of the substance in the measured liquid from the spectrum. For each bacterial cell concentration (actual absorbance value), multiple spectrum measurements were performed. In Example 6, the light reflecting part was detached and washed each time the bacterial cell concentration (actual absorbance value) in the measured liquid was changed.

[0078] FIG. 8 is a graph showing the relationship between the predicted absorbance value and the actual absorbance value in Example 6, with the x-axis representing the actual absorbance value and the y-axis representing the predicted absorbance value.

[0079] Moreover, the actual absorbance values ​​in Example 6 and the average values ​​of the actual absorbance values ​​measured multiple times are shown in Table 3 below.

[0080] [Table 3]

[0081] 8 and Table 3, in Example 6, in which the measuring device of the present invention was used and the positional relationship between the transparent part and the light reflecting part was the first positional relationship, the difference between the predicted absorbance value and the average of the actual absorbance values ​​was small, and the difference between the actual absorbance values ​​measured multiple times was also small, so it was found that the measurement accuracy of the substance concentration in the measured liquid was improved. Furthermore, in Example 6, the occurrence of measurement errors in the substance concentration could be suppressed even when the light reflecting part was detached, so it was found that the position of the light reflecting part relative to the transparent part could be matched with high precision. [Industrial Applicability]

[0082] The device for measuring the concentration of a substance in a liquid to be measured of the present invention can easily and accurately align the position of the light reflecting part placed in the liquid to be measured relative to the transparent part before and after the cleaning operation of the light reflecting part, thereby suppressing the occurrence of measurement errors before and after cleaning of the light reflecting part and enabling stable concentration measurements over a long period of time. Therefore, the device can be used in a wide range of concentration measurement fields, and is highly useful in, for example, fields where bacteria are cultivated, fields where reaction products are obtained from multiple raw materials, fields where multiple substances are mixed, etc. [Explanation of symbols]

[0083] 2 Transparent part 3. Light reflecting part 4. Light reflector fixing member 6 Light emitting part 7 Light receiving section 10. Measuring Equipment

Claims

1. a transparent portion provided on a wall surface of a container in which the liquid to be measured is contained; a light reflecting portion disposed in the liquid to be measured; a light emitting section that is disposed on an outer side of the container than the transparent section and irradiates visible light, infrared light, and / or ultraviolet light toward the light reflecting section through the transparent section; a light receiving section disposed outside the container relative to the transparent section and configured to receive visible light, infrared light, and / or ultraviolet light that is reflected from the light reflecting section via the transparent section; A measuring device for measuring a substance concentration in a liquid to be measured, wherein the light reflecting portion is attached to the transparent portion.

2. 2. The measuring device according to claim 1, wherein the light reflecting portion is attached to the transparent portion by a light reflecting portion fixing member having one end connected to the light reflecting portion and the other end connected to the transparent portion.

3. 3. The measuring device according to claim 2, wherein the light reflecting portion fixing member is a rod-shaped member.

4. 4. The measuring device according to claim 1, wherein the light reflecting portion is detachably attached to the transparent portion.

5. 4. The measuring device according to claim 1, wherein an incident angle of the visible light, infrared light and / or ultraviolet light on the light reflecting portion is in a range of 0° to 30°.

6. 4. The measuring device according to claim 1, wherein an incident angle of the visible light, infrared light and / or ultraviolet light on the light reflecting portion is in a range of 0° or more and 5° or less.

7. 4. The measuring device according to claim 1, wherein the extending direction of the light reflecting portion is parallel to the extending direction of the transparent portion.

8. The measuring device according to claim 1 , wherein the extending direction of the light reflecting portion is not parallel to the extending direction of the transparent portion.

9. The measuring device according to any one of claims 1 to 3, wherein the container is a culture tank, a liquid mixing tank for mixing a first substance and a second substance in a liquid, or a reaction tank for reacting a first substance and a second substance in a liquid.

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