Water quality analysis device

Abstract

In a water quality analyzer, contamination caused by liquid contact with the inside of a container is preferably prevented. The water quality analyzer for analyzing water to be measured comprises: a liquid contact container having an internal space through which the water to be measured flows; a measurement light irradiation optical system that irradiates the internal space with measurement light; an ultraviolet light irradiation optical system for irradiating ultraviolet light to the internal space; a detection optical system for analyzing the water to be measured on the basis of the light to be measured from the liquid contact container; and a pollution calculation control unit that calculates a pollution index indicating the degree of pollution of the liquid contact container on the basis of the analysis result of the detection optical system. The pollution calculation control unit provides a water quality analysis device that controls the intensity of the ultraviolet light in accordance with the result of the pollution index.

Description

Technical Field

[0001] The invention relates to a water quality analysis device. Background Art

[0002] In the past, in water quality analysis devices for analyzing the water quality of sample water, cleaning methods using ultrasonic waves, gas-liquid jet nozzles or wipers are known (for example, see Patent Documents 1-3). In addition, measuring devices including two light sources are known (for example, see Patent Document 4). Prior art literature Patent Literature Patent Document 1: Japanese Patent Publication No. 2015-500461 Patent Document 2: Japanese Patent Application Publication No. 2008-2956 Patent Document 3: Japanese Patent Laid-Open No. 9-54076 Patent Document 4: Japanese Patent Application Publication No. 2022-59278 Summary of the invention Technical problem to be solved by the invention

[0003] In a water quality analysis device, it is preferable to prevent contamination of the interior of a liquid contact container. Technical means for solving technical problems

[0004] In an embodiment of the present invention, a water quality analysis device for analyzing the water to be measured is provided. The water quality analysis device may include a liquid contact container having an internal space for the water to be measured to flow. Any of the above-mentioned water quality analysis devices may include a measurement light irradiation optical system for irradiating the internal space with measurement light. Any of the above-mentioned water quality analysis devices may include an ultraviolet light irradiation optical system for irradiating the internal space with ultraviolet light. Any of the above-mentioned water quality analysis devices may include a detection optical system for analyzing the water to be measured based on the measured light from the liquid contact container. Any of the above-mentioned water quality analysis devices may include a pollution calculation control unit, which calculates a pollution index representing the degree of pollution of the liquid contact container based on the analysis result of the detection optical system. In any of the above-mentioned water quality analysis devices, the pollution calculation control unit can control the intensity of the ultraviolet light according to the result of the pollution index.

[0005] In any of the above-mentioned water quality analysis devices, if the value of the pollution index is larger than a predetermined value, the pollution calculation control unit may increase the intensity of the ultraviolet light.

[0006] In any of the above-mentioned water quality analysis devices, the predetermined value may be determined according to the type of the water to be measured.

[0007] In any of the above-mentioned water quality analysis devices, the ultraviolet light irradiation optical system may intermittently irradiate the ultraviolet light while the water quality analysis device is analyzing the measurement target water.

[0008] In any of the above-mentioned water quality analysis devices, the diffusion degree of the ultraviolet light may be greater than that of the measurement light.

[0009] In any of the above-mentioned water quality analysis devices, the liquid contact container may have a scattered light window for the light to be measured to pass through. In any of the above-mentioned water quality analysis devices, the liquid contact container may have a scattered light window for the light to be measured to pass through. In any of the above-mentioned water quality analysis devices, the ultraviolet light window may be arranged at a position opposite to the scattered light window across the internal space.

[0010] Any of the above-mentioned water quality analysis devices may further include a flow rate control unit that controls the flow rate of the measurement target water to remove the contamination.

[0011] In any of the above-mentioned water quality analysis devices, when the pollution calculation control unit calculates the pollution index and the pollution index is greater than a predetermined value, the pollution calculation control unit can increase the light intensity and duty cycle of the ultraviolet light, and the flow rate control unit can repeatedly increase the flow rate of the measured object water.

[0012] In any of the above-mentioned water quality analysis devices, the liquid contact container may have a scattered light window for the light to be measured to pass through. In any of the above-mentioned water quality analysis devices, the liquid contact container may have an ultraviolet light window for the ultraviolet light to pass through. In any of the above-mentioned water quality analysis devices, the liquid contact container may have a light shielding portion, which is arranged in the internal space and guides the ultraviolet light from the ultraviolet light window to the scattered light window. In any of the above-mentioned water quality analysis devices, the inner wall of the light shielding portion may reflect the ultraviolet light.

[0013] The above summary of the invention does not list all the necessary features of the present invention. In addition, sub-combinations of these feature groups may also constitute inventions. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 1 is a diagram showing a water quality analysis device 100 according to an embodiment of the present invention. Figure 2 It is a diagram showing a configuration example of the liquid contact container 10 and the optical system. Figure 3 It is a diagram for explaining the effect of irradiation with ultraviolet light 52 . Figure 4 This is a diagram showing an example of a flowchart of the control of the ultraviolet light 52 and the control of the flow rate of the measurement target water using the pollution index. Figure 5 It is a diagram showing an example of arrangement of the light shielding portion 70 provided in the liquid contact container 10 . DETAILED DESCRIPTION

[0015] The present invention is described below by way of the embodiments of the invention, but the following embodiments do not limit the invention involved in the claims. In addition, the combination of features described in the embodiments is not necessarily required for the solution of the invention. In this specification, the same reference numerals are used for the same parts in the figures, and the description is sometimes omitted. In addition, for the convenience of description, a part of the structure is sometimes not shown.

[0016] In this specification, sometimes an orthogonal coordinate system of an X-axis, a Y-axis, and a Z-axis is used to explain technical matters. An orthogonal coordinate system only determines the relative positions of components and does not limit specific directions. For example, the Z-axis direction is not limited to being expressed as a height direction relative to the ground. In the case of "vertical" or "parallel" in this specification, for example, a deviation of about 5° may be included.

[0017] Figure 1 1 is a diagram showing a water quality analysis device 100 in an embodiment of the present invention. The water quality analysis device 100 analyzes the water to be measured. The water quality analysis device 100 measures the turbidity of the water to be measured and the concentration of a specific component contained in the water to be measured. As an example, the water to be measured is seawater. Since there are many microorganisms in seawater, seawater is used as the water to be measured in this embodiment for explanation, but the water to be measured may be fresh water, wastewater, or other liquids.

[0018] The water quality analysis device 100 includes a liquid contact container 10, a pollution calculation control unit 14, a measurement light irradiation optical system 20, and a scattered light detection optical system 30 (see Figure 2 ), the transmitted light detection optical system 40, the ultraviolet light irradiation optical system 50, the flow rate control unit 60, and the liquid circulation tube 62. The flow rate control unit 60 controls the flow rate of the water to be measured so that the water to be measured flows into the liquid contact container 10. The flow rate control unit 60 can control the flow rate by controlling a pump or by controlling a valve. The water to be measured flows into the liquid contact container 10 through the liquid circulation tube 62.

[0019] The analysis of the water to be measured is performed in the liquid contact container 10. The liquid contact container 10 has an optical window that transmits light between the inside and outside of the liquid contact container 10. Figure 1 4 and an ultraviolet window 54 are shown, but the liquid contact container 10 may also have other optical windows. Figure 2The optical system of the liquid contact container 10 and its surroundings is described. The water quality analyzer 100 is an optical analyzer that irradiates light to the water to be measured and analyzes the water to be measured based on scattered light and the like. The water quality analyzer 100 of this example is a continuous type in which the water to be measured passes through the liquid contact container 10, but is not limited to this. The water quality analyzer 100 can also perform measurements in a state in which the water to be measured does not pass through the liquid contact container 10 but stays there. Figure 1 In the following figures, the direction in which the water to be measured flows through the inside of the liquid contact container 10 is represented as the positive direction of the Z axis, and the plane perpendicular to the Z axis direction is represented as the XY plane.

[0020] The contamination calculation control unit 14 is connected to the scattered light detection optical system 30 via the scattered light detection signal line 36, connected to the transmitted light detection optical system 40 via the transmitted light detection signal line 46, connected to the ultraviolet light irradiation optical system 50 via the ultraviolet light detection signal line 56, and connected to the flow rate control unit 60 via the flow rate control signal line 66. As described later, the contamination calculation control unit 14 can calculate the contamination of the liquid contact container 10 based on the analysis results of one or both of the scattered light detection optical system 30 and the transmitted light detection optical system 40. The contamination calculation control unit 14 can control the ultraviolet light irradiation optical system 50 based on the result of the calculation to change the intensity of the ultraviolet light. The contamination calculation control unit 14 can control the flow rate control unit 60 based on the result of the calculation to change the flow rate of the measurement target water to remove the contamination of the liquid contact container 10.

[0021] Figure 2 It is a diagram showing a configuration example of the liquid contact container 10 and the optical system. Figure 2 The liquid contact container 10 is a cross section of the XY plane. The liquid contact container 10 has an internal space 12 through which the water to be measured flows. Figure 2 In the figure, the water to be measured flows toward the front of the paper surface (positive direction of the Z axis).

[0022] The liquid contact container 10 has a measurement light window 24, a scattered light window 34, a transmitted light window 44, and an ultraviolet light window 54. The measurement light window 24, the scattered light window 34, the transmitted light window 44, and the ultraviolet light window 54 are optical windows provided so that light can pass between the internal space 12 and the outside of the liquid contact container 10. In this specification, the measurement light window 24, the scattered light window 34, the transmitted light window 44, and the ultraviolet light window 54 are sometimes collectively referred to as optical windows. Figure 2 In the embodiment, the optical window is arranged in the internal space 12, but it can also be arranged outside the liquid contact container 10, or it can be buried in the wall of the liquid contact container 10.

[0023] The measuring light irradiation optical system 20 irradiates the measuring light 22 to the internal space 12. The measuring light irradiation optical system 20 can irradiate the measuring light 22 from the outside of the liquid contact container 10 to the measuring object water in the internal space 12. The measuring light irradiation optical system 20 includes a lamp or an LED as a light source. The measuring light 22 can be white light or monochromatic light. The measuring light irradiation optical system 20 is set at a position where the measuring light 22 is irradiated from the measuring light window 24 to the internal space 12 of the liquid contact container 10.

[0024] When the measuring light 22 is irradiated to the measuring object water, part of the measuring light 22 is scattered or absorbed by the components and suspended matter contained in the measuring object water, and the other part is not scattered or absorbed but is transmitted. In addition, when the measuring light 22 with a shorter wavelength is irradiated to the measuring object water containing a specific chemical substance, fluorescence inherent to the chemical substance is generated.

[0025] The scattered light detection optical system 30 detects scattered light 32 from the water to be measured. The scattered light 32 may be scattered light, fluorescence, or ultraviolet light as described below. The scattered light detection optical system 30 is provided at a position to detect the scattered light 32 emitted from the scattered light window 34 .

[0026] The transmitted light detection optical system 40 detects the transmitted light 42 from the water to be measured. The transmitted light 42 may contain fluorescence or ultraviolet light as described below. The transmitted light detection optical system 40 is arranged at a position to detect the transmitted light 42 emitted from the transmitted light window 44. The scattered light detection optical system 30 and the transmitted light detection optical system 40 include a light receiving element such as a photodiode or a photomultiplier tube to detect the intensity of the scattered light 32 and the transmitted light 42.

[0027] When the turbidity of the water to be measured increases, the intensity of the scattered light 32 increases. When the turbidity of the water to be measured increases, the amount of light absorbed after subtracting the intensity of the transmitted light 42 from the intensity of the measuring light 22 also increases. In addition, when the concentration of the substance to be measured increases, the intensities of the scattered light 32 and the fluorescence increase, and the amount of light absorbed also increases. Therefore, by detecting the intensity of at least one of the scattered light 32, the fluorescence, and the transmitted light 42, the turbidity of the water to be measured or the concentration of the substance to be measured can be calculated. In this specification, the scattered light 32 and the transmitted light 42 are sometimes collectively referred to as the measured light 48. In addition, the scattered light detection optical system 30 and the transmitted light detection optical system 40 are sometimes collectively referred to as the detection optical system 58. The scattered light detection optical system 30 and the transmitted light detection optical system 40 are connected by a signal line not shown in the figure, and the values ​​of the intensities detected by each can be communicated. The scattered light detection optical system 30 and the transmitted light detection optical system 40 can include a computing unit.

[0028] The detection optical system 58 can analyze the measurement target water based on the measured light 48 from the liquid contact container 10. The detection optical system 58 can calculate the above-mentioned turbidity or concentration. The detection optical system 58 can include at least one of the scattered light detection optical system 30 and the transmitted light detection optical system 40. As an example, the detection optical system 58 only includes the scattered light detection optical system 30, and the turbidity of the measurement target water can also be calculated based on the intensity of the detected scattered light 32.

[0029] When there are microorganisms in the water to be measured, the microorganisms sometimes adhere to the optical window of the liquid contact container 10 to form contamination. The above-mentioned contamination is, for example, a biofilm. The so-called biofilm is an aggregate of bacteria that adhere and proliferate through extracellular polymers (EPS) produced by cells on the surface of a substance in contact with a solution in which microorganisms exist. In this specification, contamination mainly refers to biofilm. When contamination is formed on the optical window, errors are easily generated in the analysis results due to the blocking of light passing through the optical window.

[0030] The ultraviolet light irradiation optical system 50 irradiates ultraviolet light 52 to the internal space 12. The ultraviolet light irradiation optical system 50 can irradiate ultraviolet light 52 from the outside of the liquid contact container 10 to the optical window of the internal space 12. Since ultraviolet light has a bactericidal effect, it can sterilize microorganisms present in the water to be measured, and the formation of contamination can be prevented. The ultraviolet light irradiation optical system 50 is set at a position where ultraviolet light 52 is irradiated from the ultraviolet window 54 to the internal space 12 of the liquid contact container 10.

[0031] The ultraviolet light irradiation optical system 50 includes a lamp or an LED as a light source. The wavelength of the ultraviolet light 52 may be UV-C (~280nm). As an example, when the intensity of the ultraviolet light 52 is at full power, the radiation intensity at the center is 0.2mW / cm 2 The radiation intensity at the periphery is 0.12mW / cm 2 The central portion is the portion of the light source's emission surface that intersects the optical axis, and the peripheral portion is the portion of the light source's emission surface that is farthest from the optical axis.

[0032] The ultraviolet light 52 may be diffuse light. The diffusion degree of the ultraviolet light 52 may be greater than that of the measuring light 22. The so-called diffusion degree may be the degree to which the light expands during the period when the light advances a specified distance. Thus, the ultraviolet light 52 irradiated to the internal space 12 can easily reach multiple optical windows. The ultraviolet light irradiation optical system 50 can irradiate the ultraviolet light 52 to the internal space 12 so that the ultraviolet light 52 reaches all optical windows provided on the liquid contact container 10.

[0033] The ultraviolet light window 54 may be disposed at a position opposite to the scattered light window 34 across the internal space 12. Figure 2In the embodiment, the ultraviolet light window 54 is arranged at a position opposite to the scattered light window 34 in the Y-axis direction. The optical axis of the ultraviolet light 52 may be parallel to the Y-axis direction. As described above, the intensity of the ultraviolet light 52 is stronger at the center than at the periphery. Therefore, by arranging the ultraviolet light window 54 and the scattered light window 34 relative to each other, the amount of ultraviolet light irradiated on the scattered light window 34 can be increased. Thus, the contamination of the scattered light window 34 through which the scattered light 32 directly related to the measured value passes can be prevented.

[0034] The ultraviolet light irradiation optical system 50 may intermittently irradiate the ultraviolet light 52 during the period when the water quality analyzer 100 analyzes the water to be measured. As an example, the measuring light irradiation optical system 20 and the ultraviolet light irradiation optical system 50 alternately irradiate the measuring light 22 and the ultraviolet light 52 during the period when the water quality analyzer 100 analyzes the water to be measured. In this example, the period of analyzing the water to be measured refers to the period during which the measuring light 22 is intermittently irradiated in order to analyze the same water to be measured. During the period of analyzing the water to be measured, the period of cleaning or calibration of the water quality analyzer 100 may not be included. Specifically, the measuring light irradiation optical system 20 may irradiate the measuring light 22 for half of each unit time, and the ultraviolet light 52 may be irradiated by the ultraviolet light irradiation optical system 50 for the rest of the time. In other words, half of each unit time may be the time for irradiating the measuring light 22, and the rest of the time may be the time for irradiating the ultraviolet light 52. The above-mentioned unit time is repeated during the period of analyzing the water to be measured. The unit time may be 1 second, 1 minute, or twice the time required to receive the amount of light 48 required for analysis. This can extend the life of the light source and prevent the ultraviolet light 52 from affecting the analysis of the water to be measured.

[0035] The contamination calculation control unit 14 calculates a contamination index indicating the degree of contamination of the liquid contact container 10 based on the analysis result of the detection optical system 58. The contamination index is expressed by the following formula as an example. Pollution index = 1 - (intensity of scattered light 32 + intensity of transmitted light 42) / (intensity of initial scattered light + intensity of initial transmitted light) The contamination index takes a value between 0 and 1. A higher value of the contamination index means that the liquid contact container 10 is contaminated. The contamination index may also be calculated using only the scattered light 32 or the transmitted light 42 .

[0036] The pollution calculation control unit 14 can control the intensity of the ultraviolet light 52 according to the result of the pollution index. The pollution calculation control unit 14 can change the intensity of the ultraviolet light 52 by controlling the ultraviolet light irradiation optical system 50. When the value of the pollution index is greater than a predetermined value, the pollution calculation control unit 14 can increase the intensity of the ultraviolet light 52. As an example, the predetermined value is 0.2. Thereby, the formation of pollution can be further suppressed.

[0037] In the biofilm formation stage, bacteria attached to the surface of the material generate EPS, thereby forming microcolonies or agglomerates, which promote the formation of the biofilm. That is, by generating EPS, the biofilm grows rapidly. The ultraviolet light 52 inhibits the generation of the above-mentioned EPS, thereby inhibiting the formation of the biofilm.

[0038] The growing biofilm firmly adheres to the surface of the material and becomes difficult to remove. Therefore, it is preferred to adjust the intensity of the ultraviolet light 52 to stop the biofilm formation stage before the EPS generation stage.

[0039] The stage in which the biofilm grows rapidly by producing EPS is manifested as a sharp increase in the pollution index over time. Therefore, it is preferred to experimentally obtain the value of the pollution index when the pollution index begins to increase sharply (called the critical pollution index value) in advance. The pollution calculation control unit 14 can use the critical pollution index value as the predetermined value, can use a value 0.8 times the critical pollution index value as the predetermined value, and can also use a value 0.5 times the critical pollution index value as the predetermined value.

[0040] The critical pollution index value varies depending on the type of the water to be measured. The predetermined value can be determined according to the type of the water to be measured. Thus, the formation of pollution can be effectively prevented for each water to be measured.

[0041] The formation of biofilm is prevented by ultraviolet irradiation, and contamination will not be firmly attached to the optical window. Therefore, most of the contamination is removed by the measurement object water flowing through the internal space 12. The flow rate control unit 60 can also control the flow rate of the measurement object water to remove contamination. Since the formation of biofilm is prevented by ultraviolet irradiation, even a lighter cleaning method such as controlling the flow rate of the measurement object water can remove contamination. In this specification, as a method for removing contamination, the control of the flow rate of the measurement object water is used, but other cleaning methods can also be used.

[0042] Figure 3 52 is a diagram illustrating the effect of irradiation with ultraviolet light 52. The inventor conducted a comparative experiment to verify the effect of ultraviolet light 52 in preventing pollution. In the experiment, the state and transmittance of the optical window after the water to be measured flowed for 20 days were measured. The water to be measured was seawater. Figure 3 The upper row represents examples, and the lower row represents comparative examples. Figure 3 The second column from the left indicates whether or not the ultraviolet light 52 is irradiated. In the embodiment, the ultraviolet light 52 is continuously irradiated, while in the comparative example, the ultraviolet light 52 is not irradiated.

[0043] Figure 3The third column from the left represents the contamination of the optical window. The figure of the optical window shown in the third column is a visual schematic diagram. In the embodiment, small contamination is partially formed (black ellipse in the figure), but most of the contamination is not formed. On the other hand, in the comparative example, thin contamination is formed on one side of the optical window (shadow in the figure), and darker contamination (black ellipse in the figure) is formed therein.

[0044] Figure 3 The fourth column from the left shows the transmittance of light. The transmittance is based on the initial transmittance before the water to be measured is circulated as 100%. In the embodiment, a transmittance of 98% was measured, but in the comparative example, a transmittance of 74% lower than that in the embodiment was measured. That is, it was confirmed that contamination can be prevented to a large extent by irradiating ultraviolet light 52.

[0045] Figure 4 1 is a diagram showing an example of a flow chart of controlling the ultraviolet light 52 and controlling the flow rate of the water to be measured using the pollution index. In step S100, the pollution calculation control unit 14 calculates the above-mentioned pollution index. In step S102, the pollution calculation control unit 14 determines whether the pollution index is greater than a predetermined value. In this example, the predetermined value is 0.2. In the case where the value of the pollution index is not greater than the predetermined value, the subsequent processing may not be performed, or the pollution index may be calculated again.

[0046] When the pollution index is greater than a predetermined value, in step S104, the pollution calculation control unit 14 increases the light intensity and duty cycle of the ultraviolet light 52. Increasing the light intensity of the ultraviolet light 52 may be increasing the output of the ultraviolet light irradiation optical system 50 or increasing the drive current. Figure 4 In the embodiment of the present invention, the light intensity and duty cycle of the ultraviolet light 52 are increased by 10%.

[0047] In step S106, the contamination calculation control unit 14 determines whether the light intensity and duty ratio of the ultraviolet light 52 are 100%. The light intensity of the ultraviolet light 52 being 100% means that the output of the ultraviolet light irradiation optical system 50 is maximum.

[0048] When both the light intensity and duty cycle of the ultraviolet light 52 are 100%, in step S108, the pollution calculation control unit 14 determines whether the pollution index value is greater than a predetermined value. The predetermined value in step S108 may be greater than the predetermined value in step S102. The predetermined value in this example is 0.7.

[0049] In step S108, when the value of the pollution index is greater than a predetermined value, the pollution calculation control unit 14 determines that it is necessary to maintain the water quality analysis device 100 or replace a component. In this case, the pollution calculation control unit 14 may notify the outside that maintenance or replacement of components is required. In step S108, when the value of the pollution index is smaller than the predetermined value, the pollution calculation control unit 14 may not perform special processing. In this case, the pollution calculation control unit 14 may periodically and continuously check whether the value of the pollution index is greater than the predetermined value.

[0050] If the light intensity and duty cycle of the ultraviolet light 52 are not 100% in step S106, the flow rate control unit 60 increases the flow rate of the water to be measured in step S110. As an example, the flow rate is increased once every hour for tens of seconds, and the flow rate during the increase is 200% to 300% of the normal flow rate. The pollution calculation control unit 14 can increase the flow rate of the water to be measured by sending a command to the flow rate control unit 60.

[0051] In step S112, the pollution calculation control unit 14 maintains the delay time, the light quantity and duty ratio of the ultraviolet light 52, and the flow rate of the measured water to increase. The delay time is the period until the pollution reduction effect is apparent. In this example, a period of 1 to 3 days is set as the delay time.

[0052] In step S114, the pollution calculation control unit 14 determines whether the delay time has elapsed. If the delay time has not elapsed, the pollution calculation control unit 14 continues to increase the light intensity and duty cycle of the ultraviolet light 52 and the flow rate of the water to be measured. If the delay time has elapsed, the operation of step S100 is performed again. The water quality analysis device 100 can repeat Figure 4 operation.

[0053] Figure 5 1 is a diagram showing an example of the configuration of the light shielding portion 70 provided in the liquid contact container 10. The liquid contact container 10 of this example has the light shielding portion 70 provided in the internal space 12. When the ultraviolet light 52 is irradiated to the internal space 12, the liquid contact container 10 may be degraded by the ultraviolet light 52. By providing the light shielding portion 70, the ultraviolet light 52 irradiated on the inner wall of the liquid contact container 10 can be reduced, and the degradation of the liquid contact container 10 can be prevented. In addition, by providing the light shielding portion 70, the influence of stray light in the measurement can be reduced.

[0054] The light shielding portion 70 may be provided to shield at least a portion of a straight line connecting the ultraviolet light window 54 and the inner wall of the liquid contact container 10. The light shielding portion 70 may be provided to shield all straight lines connecting the ultraviolet light window 54 and the inner wall of the liquid contact container 10. The light shielding portion 70 guides the ultraviolet light 52 from the ultraviolet light window 54 to the scattered light window 34. The light shielding portion 70 may guide the ultraviolet light 52 from the ultraviolet light window 54 to the measuring light window 24, or to the transmitted light window 44. The inner wall of the light shielding portion 70 may reflect the ultraviolet light 52. The inner wall of the light shielding portion 70 may be a wall surface of the light shielding portion 70 that faces the optical path through which the measuring light 22, the scattered light 32, the transmitted light 42, or the ultraviolet light 52 passes, a wall surface that does not face the inner wall of the liquid contact container 10, or a wall surface that faces other parts of the light shielding portion 70. Thus, the ultraviolet light 52 can be guided to all optical windows.

[0055] The outer wall of the light shielding portion 70 can absorb the ultraviolet light 52. The outer wall of the light shielding portion 70 can be a wall surface of the light shielding portion 70 that does not face the optical path through which the measuring light 22, the scattered light 32, the transmitted light 42, or the ultraviolet light 52 passes, can be a wall surface facing the inner wall of the liquid contact container 10, or can be a wall surface that does not face other parts of the light shielding portion 70. In this way, the ultraviolet light 52 irradiated on the inner wall of the liquid contact container 10 can be further reduced. The inner wall of the light shielding portion 70 can be coated with a material having a high reflectivity for the ultraviolet light 52. The outer wall of the light shielding portion 70 can be coated with a material having a low reflectivity for the ultraviolet light 52. The inner wall of the light shielding portion 70 has a higher reflectivity for the ultraviolet light 52 than the outer wall of the light shielding portion 70.

[0056] The light shielding portion 70 can be fixed to the liquid contact container 10 by screws, adhesives, etc. An adhesive that softens at a temperature lower than the heat-resistant temperature of the light shielding portion 70 and the liquid contact container 10 can be used. The light shielding portion 70 can also be mechanically fixed by making the shape and size consistent with the wall surface of the liquid contact container 10. The light shielding portion 70 can also be fixed to the liquid contact container 10 by heating or other methods. Maintenance can be easily performed by replacing only the light shielding portion 70 that is irradiated with ultraviolet light 52 and easily deteriorated.

[0057] The present invention has been described above using the embodiments, but the technical scope of the present invention is not limited to the scope described in the above embodiments. It is clear to those skilled in the art that various changes or improvements can be made to the above embodiments. According to the description of the patent claims, the implementation of such changes or improvements is also included in the technical scope of the present invention. Description of symbols

[0058] 10…liquid contact container, 12…internal space, 14…contamination operation control unit, 20…measuring light irradiation optical system, 22…measuring light, 24…measuring light window, 30…scattered light detection optical system, 32…scattered light, 34…scattered light window, 36…scattered light detection signal line, 40…transmitted light detection optical system, 42…transmitted light, 44…transmitted light window, 46…transmitted light detection signal line, 48…measured light, 50…ultraviolet light irradiation optical system, 52…ultraviolet light, 54…ultraviolet light window, 56…ultraviolet light detection signal line, 58…detection optical system, 60…flow rate control unit, 62…liquid flow tube, 66…flow rate control signal line, 70…light shielding unit, 100…water quality analysis device.

Claims

1. A water quality analysis device for analyzing water to be measured, characterized in that: include: a liquid contact container having an internal space for the water to be measured to flow; a measurement light irradiation optical system for irradiating the internal space with measurement light; an ultraviolet light irradiation optical system, the ultraviolet light irradiation optical system irradiating ultraviolet light to the internal space; a detection optical system that analyzes the water to be measured based on the light to be measured from the liquid contact container; and a contamination calculation control unit that calculates a contamination index indicating a degree of contamination of the liquid contact container based on an analysis result of the detection optical system, The pollution calculation control unit controls the intensity of the ultraviolet light according to a result of the pollution index.

2. The water quality analysis device according to claim 1, characterized in that: The pollution calculation control unit increases the intensity of the ultraviolet light if the value of the pollution index is larger than a predetermined value.

3. The water quality analysis device according to claim 2, characterized in that: The predetermined value is determined according to the type of the measurement target water.

4. The water quality analysis device according to claim 1, characterized in that: The ultraviolet light irradiation optical system intermittently irradiates the ultraviolet light while the water quality analysis device is analyzing the measurement target water.

5. The water quality analysis device according to claim 4, characterized in that: The ultraviolet light irradiation optical system and the measuring light irradiation optical system alternately irradiate the ultraviolet light and the measuring light while the water quality analysis device is analyzing the water to be measured.

6. The water quality analysis device according to claim 1, characterized in that: The ultraviolet light diffuses to a greater extent than the measuring light.

7. The water quality analysis device according to claim 1, characterized in that: The liquid contact container has: a scattered light window, through which the measured light passes; as well as an ultraviolet light window through which the ultraviolet light passes, The ultraviolet light window is arranged at a position opposite to the scattered light window across the internal space.

8. The water quality analysis device according to claim 1, characterized in that: The device further includes a flow rate control unit that controls the flow rate of the measurement target water to remove the contamination.

9. The water quality analysis device according to claim 8, characterized in that: When the pollution calculation control unit calculates the pollution index and the pollution index is greater than a predetermined value, The pollution calculation control unit increases the light intensity and duty cycle of the ultraviolet light. The flow rate control unit repeatedly performs an operation of increasing the flow rate of the measurement target water.

10. The water quality analysis device according to any one of claims 1 to 9, characterized in that: The liquid contact container has: a scattered light window, through which the measured light passes; as well as an ultraviolet light window through which the ultraviolet light passes, The liquid contact container has a light shielding portion, which is disposed in the internal space and guides the ultraviolet light from the ultraviolet light window to the scattered light window. The inner wall of the light shielding portion reflects the ultraviolet light.

Images