JP2000039431A - On-line water quality meter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an on-line water quality meter for suppressing the generation of microbes and germs in a channel without being attacked by fluid by forming a liquid-contacting part on the inner surface of the channel in a motherboard using a corrosive-resistant material or an antibacterial material. SOLUTION: All channels 313 in a water quality meter are formed three- dimensionally in a three-dimensional motherboard 101, and fluid 314 flows in the channels 313. A liquid-contacting part 315 on the inner surface of the channels 313 cannot be attacked by the fluid 314 and corrosion resistance or antibacterial property needs to be improved for suppressing the generation of microbes and germs in the channels 313. Therefore, after a corrosion-resistant material such as fluororesin, liquid-shaped rubber, and electroless plating or an antibacterial material such as silver, copper oxide, and titanium oxide 316 is allowed to flow to the channels 313, heat is applied for coating by several μm in thickness, thus enlarging the range of applicable fluid being generated due to the material restriction of the motherboard 101 being formed in one piece by the light-shaping method.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water distribution monitoring system for water supply, and more particularly to an on-line water quality meter for coating a liquid contact portion on the inner surface of a flow channel with a corrosion-resistant material or an antibacterial material.

[0002]

2. Description of the Related Art Conventionally, as this kind of distribution water quality monitoring system, there is an automatic water quality measurement system in Tokyo, for example.
"Measurement and Control" Vol. 33 (issued in 1994), page 649, introduces the specifications of the system and the water quality meter used at that time.

In this distribution water quality monitoring system, a water quality meter is installed for each system of a company-side piping network, and continuously measures distribution water quality for each system and periodically transmits a signal to a center by a telemeter. I am taking. In addition, as a means of measuring water quality of water distribution on the customer side, water quality measurement by manual analysis or offline measurement with a portable water quality meter has been performed. In such a conventional system, the water quality meter is arranged for each water distribution system on the business side, so that the number of installations is small, and there is an advantage that the average water quality of the supply water for each system can be grasped.
Finally, there is a disadvantage that the quality of water consumed by consumers cannot be grasped.

[0004] The water quality of distribution water is measured and controlled at the distribution supply point, but the water quality deteriorates while passing through the distribution pipe network. Specifically, the concentration of residual chlorine to maintain sterilization power decreases due to chemical reactions in the water distribution equipment and with the contained substances, the chromaticity increases due to rust in the pipeline, and the adherence on the pipe wall peels off For example, turbidity increases due to the above. These can also occur in the mains of the system, but rather are more pronounced in the customer's plumbing.

[0005] It is known that the residual chlorine concentration decreases in proportion to the residence time, and as a result, the residence time is longer in the terminal piping than in the system main line with constant water flow. In extreme cases, the concentration is reduced to zero, and it is possible for consumers to drink water that has lost sterilizing power. When the residual chlorine concentration decreases, the bactericidal power of water decreases, and there is a possibility that microorganisms, particularly pathogenic microorganisms (for example, O-157) may proliferate, causing social problems in terms of safety and health. In addition, if chlorine is injected excessively for safety, the residual chlorine concentration will be secured, but the chlorine concentration will increase. As a result, the so-called "kalky" odor becomes a problem, and harmful substances such as trihalomethane, which is a by-product of chlorine Are generated and leave challenges in terms of safety.

The same can be said for chromaticity, turbidity, etc. as a result of the longer residence time. Especially in apartment houses and business establishments, there is a water receiving tank, and this problem becomes prominent when the management is not appropriate.

[0007] In this way, the ideal water quality management is to measure the quality of the terminal water finally consumed by the consumer, monitor whether or not the value is appropriate, and manage the value so that it is appropriate. . Conventionally, this could not be realized for the following reasons.

(1) The water quality meter is large (eg, 1.2 mx 1.8)
mx 0.6m), so it cannot be installed in homes or apartments that are consumers.

(2) Since the unit price of the water quality meter and the construction cost are high, the number of installed water quality meters is limited due to budget constraints.

(3) It is difficult to introduce it into ordinary households because maintenance requires special skills and safety needs to be considered.

[0011] On the other hand, the water quality at the end of water distribution can be measured by hand analysis or the water quality measurement at the end of distribution using a portable water quality meter.
There is a drawback that it takes a long time to obtain the results, and it is not possible to grasp the range of change in the day or unsteady behavior because continuous water quality data cannot be obtained.

In this type of data, the maximum value in an unsteady state is important, and it is important to establish a system operation / control method to minimize the maximum value. In this sense, there is a drawback that the above-mentioned manual analysis or portable water quality meter cannot be used as a water quality meter of a monitoring system. Also, in rare cases, the measurement items and installation locations are limited even at the end of the water pipe (for example, only one residual chlorine analyzer is installed per 10,000 to tens of thousands of households), and online measurement has been performed. there were.

[0013] However, the on-line water quality meter used in the conventional system is an analyzer that is used in a water purification plant even for a single item measurement, and is not only large and expensive, but also has a large installation cost. It was also difficult to secure the water quality, and it was difficult to measure the water quality in a fine-grained manner with sufficient measurement items and locations.

Therefore, in order to realize an inexpensive and ultra-small water quality meter, the flow path is a three-dimensional integrally formed flow path. For this, UV-curable plastic was used and manufactured by stereolithography, but currently available stereolithography resins are epoxy or urethane, which has problems with corrosion resistance or antibacterial properties, and impairs reliability. Was also considered.

[0015]

SUMMARY OF THE INVENTION In order to realize an ultra-small water quality meter suitable for finely monitoring the quality of water supplied to a customer side of a water supply system, a stereolithography method using a three-dimensional three-dimensional flow path is realized. However, there are restrictions on applicable materials in the present forming method.

An object of the present invention is to use a cleaning solution or a reagent in addition to the sample water and zero water, so that it is not eroded by a fluid,
An object of the present invention is to provide an on-line water quality meter that suppresses the generation of microorganisms and bacteria in a flow path.

[0017]

In order to solve the problems of the prior art, a three-dimensional three-dimensional flow channel manufactured by coating a liquid contact portion of a fluid circuit with a corrosion-resistant material or an antibacterial material and manufacturing it by a stereolithography method. Can be used as an on-line water quality meter channel.

[0018]

FIG. 1 is a diagram showing a basic configuration of a terminal water distribution monitoring system as an embodiment of the present invention. Raw water such as rivers, lakes, wells, etc. is purified by the water purification facility 1 into water suitable for drinking and sent to the water distribution facility 2. Drinking water sent from the water distribution facility 2 is distributed to the main water distribution line 4, the distribution system piping 5
The water quality meter 8 may enter the water quality meter 8 through the water distribution line 6 on the water supply business side and the water distribution line 7 on the customer side. The output of the water quality meter 8, which measures the water quality of drinking water online, is sent to the management center 3 through media such as wireless, wired, and satellite, where necessary data processing is performed to purify the water so that the water quality becomes an appropriate value. Controls operating conditions of facilities and water distribution facilities.

FIG. 2 shows an installation example of a water quality meter in a customer of such a distribution end monitoring system. The drinking water branched from the water distribution system pipes 5 and 6 on the water supply company side or the water distribution pipe 7 on the customer side enters the water distribution facility 11 via the shutoff valve 10 and the water meter 9, and at the same time, the water quality of the plurality of items is measured by the water quality meter 8. A measurement is taken. The water distribution facility 11 is composed of a piping network, and drinking water is supplied to a customer from one location through a water tap 12 such as a faucet. The water quality meter 8 is the water meter 9 of FIG.
In addition to being installed in front and rear, it can be installed in a water meter storage box, and has a size that can be easily installed in manholes, fire hydrants, customer facilities, near water taps, and so on.

FIG. 3 is a diagram showing the internal structure of the water quality meter. The sample water introduced from the water distribution pipes 5, 6, and 7 passes through a sample introduction section 13 and reagent mixing sections 14a to 14c for a plurality of measurement components.
After being introduced into the plurality of measurement / analysis units 15 to 17 and measured in a predetermined sequence for each item, it is converted into an electric signal and transmitted to the signal processing / control unit 18. The signal processing / control unit 18 operates by receiving power supply from the power supply unit 20, is converted into a transmission signal for transmission by the output / transmission unit 19, and is then transmitted by radio 21 or by a telemeter through a dedicated line or a public line. It is transmitted to the management center.

FIG. 4 shows an embodiment in which the water meter 9 and the water quality meter 8 are integrated. When the water quality meter is miniaturized by microfabrication, an integrated structure becomes possible. The flow rate is measured by flowing through the water meter via 10, and a part of the flow rate is supplied to the water quality meter 8 via the sample introduction pipe 22. With this configuration, it is possible to install the water meter and the water quality meter integrally on the pipe and store it in the water meter box.As a result, there is no special installation place or installation work, and it is the same as installing a water meter. Mounting is possible with simplicity.

As described above, the use of microfabrication has made it possible to achieve ultra-small size, reduce power consumption and reduce the amount of sample water and reagents used, and use batteries as power sources and employ wastewater recovery or evaporation methods. In addition, the use of a wireless line for data transmission eliminates the need for wiring and drainage work when installing a water quality meter, greatly improving the freedom of installation of the water quality meter.

Next, a specific configuration of the embodiment will be described with reference to FIG. Drinking water (sample water) 52 flowing through the water distribution pipe 51 on the water supply company side or the customer side is sampled via a pipe 53, passed through a manual valve 54, a pipe 55, a pressure reducing valve 56, and further connected to a pipe 57, The water is drained from the valve 58 and the drain pipe 59 to the drain groove 60.

From the pipe 57, a part of the sample water 52 maintained at a constant pressure is branched by a pipe 61, passes through a manual valve 62, passes through a filter 63 for removing large foreign matter in the sample water, and passes through a filter 63 in the analyzer main body 64. Is led to the defoaming tank 66 through the flow path 65. Bubbles 67 contained in the sample water 52 inside the defoaming tank 66 accumulate in the upper part of the defoaming tank 66, and are discharged from the analyzer main body 64 via a flow path 68, a solenoid valve 69, and a flow path 70 as needed. Discarded in the groove 60.

On the other hand, the sample water 71 from which the bubbles in the defoaming tank 66 have been removed is guided to a metering pump 74 via a flow path 72 and an electromagnetic valve 73. Further, the sample water 71 has a plurality of solenoid valves 75.
Via a, 75b, and 75c, items are selectively sent to a plurality of analysis units 76, 77, and 78 that analyze independent items. The analysis section has a common mounting shape and piping arrangement, and is detachably held on the analyzer main body 64 so as to be completely the same or compatible with other analysis sections.

A plurality of cartridges 79, 80 and 81 each containing a liquid are detachably held outside the analyzer main body, and the liquid inside the cartridge is supplied to the analyzer main body 64. Liquid 8 from cartridge 79
The analysis unit 7 is guided to a solenoid valve 83 and a metering pump 84 via a plurality of solenoid valves 85a, 85b, 85c.
6, 77, 78. Similarly, the liquid 86 in the cartridge 80 passes through the pump 87 and then to the analysis section via a plurality of solenoid valves 88a, 88b and 88c, and the liquid 89 in the cartridge 81 passes through the pump 90 and the solenoid valves 91a and 91a. The analysis unit 7 is connected to the analysis unit 7 via 91b and 91c.
6, 77, 78. At this time, although the detailed structure of each analysis unit will be described later, it is composed of a reagent mixing unit for mixing or selecting and reacting each of the fluids using a microfabrication technology and a measurement analysis unit, and is extremely miniaturized. It has the function of one analyzer. The waste liquid 92 after the completion of each analysis is discharged out of the apparatus via the flow path 70. If the waste liquid 92 is harmful or there is no drainage system,
It is discharged to the collection container 95 via the electromagnetic valve 93 and the flow path 94.

In the above configuration, the sample water 52 sampled from the drinking water distribution pipe 51 is guided to the liquid in the plurality of cartridges and the reagent mixing section in the analysis section by sequence-controlling a plurality of pumps and solenoid valves. The reaction is performed, and the result is measured by the measurement and analysis unit. At this time, a reagent reaction may not be required depending on an analysis item. In this case, no reagent is selected.

As a typical application example, tap water is used as the sample water 52, and a reagent (eg, DPD or ortho-tolidine) that reacts with residual chlorine in the liquid 82 in the cartridge 79 to form a color.
The cleaning liquid (for example, diluted hydrochloric acid or neutral detergent) is selected as the liquid 86 in the cartridge 80, and the reference liquid (for example, pure water or calibration liquid) is selected for the liquid 89 in the cartridge 81. These are sequence-controlled at a predetermined timing and guided to each analysis unit. For example, the analyzer 76 is used as a residual chlorine meter, the analyzer 77 is used as a chromaticity meter, and the analyzer 78 is used as a turbidity meter. The liquid 82 containing the reagent is supplied to the analyzer 7 assigned to the residual chlorine meter.
Use only for 6. If the type of the reagent is changed, the measurement item can be changed, and the selection of which measurement item is assigned to which analysis unit is also free.

In the case of a residual chlorine meter, the degree of color development of the sample water is measured by a reagent reaction by an absorbance method. In the case of a chromaticity meter, the absorbance of the sample water itself is measured without using a reagent, but the absorbance is low. The measurement method is a comparative measurement method with liquid (pure water). The reference liquid is measured at a predetermined cycle, and the baseline of the zero point is corrected. On the other hand, the turbidity meter used a method in which the number of turbid particles in the sample water was counted and the turbidity was converted without using any reagent or reference solution.

In addition, if an analyzer having a built-in electrode is attached to the analyzer, the function of a conductivity meter or a pH meter can be added without changing the structure of the analyzer.

The cleaning liquid (liquid 86) is guided to each analysis section at predetermined intervals, and cleans the flow path, cells, electrodes, etc. in the analysis section. Foreign matter generated by the washing is washed away with the sample water 71 or the reference liquid 89.

Next, the flow path system used in this embodiment will be described with reference to FIG. All the flow paths (flow paths 65, 68, 70, 7) inside the analyzer 64 described with reference to FIG.
2, 92, 94, etc.) are three-dimensionally formed inside the three-dimensional motherboard 101. The three-dimensional motherboard 10
1 has a rectangular parallelepiped shape, and its outer peripheral surface can hold a plurality of valves, pumps, analyzers, etc. shown in FIG. 5 directly or through a sealant without using piping. Are formed with a plurality of flow path openings 102 and screw holes 103.

The internal flow path of the three-dimensional motherboard 101 is shown in FIG. 7 when the resin is removed and only the flow path is three-dimensionally represented. Conventionally, it is difficult to realize such a three-dimensional three-dimensional channel, and if it is to be forcibly manufactured, the two-dimensional channel has been formed by overlapping a plurality of machined plates and joining them. In this embodiment, an ultraviolet curable plastic is used, and a laser molding method is employed in which a liquid resin is selectively irradiated with an ultraviolet laser beam, and only a portion irradiated with the light is cured to form a shape.

In this stereolithography method, an uncured liquid is left as it is without irradiating light to a portion corresponding to the flow path, and after molding, the uncured resin is washed away to form an arbitrary three-dimensional flow path. The resin used was an ultraviolet-curing transparent epoxy resin, so that the inside of the flow path could be observed from the outside. Also, stereolithography does not require a special mold
D (computer aided design) can be realized quickly and inexpensively with only three-dimensional design data, and has the advantage of improving the reliability of the piping connection.

Next, referring to FIG. 8, the details of the analyzers (76, 77, 78) shown in FIG. 5 will be described. Although each analyzer has a different measurement principle depending on the purpose of measurement (residual chlorine meter and chromaticity meter adopt absorbance measurement for light of a predetermined wavelength, and turbidity meter adopts a particle number coefficient formula for measuring the number of changes of scattered light. In addition, it is also possible to mount an analysis section having a built-in electrode for measuring conductivity and pH), the mounting dimensions and the flow path are common, and the module is modularized.

On the motherboard 101, three analysis sections are configured to be detachable via a sealing member.
It is optional to place the analysis unit of any item described in FIG. 5 where. By selecting an analysis unit selection and a liquid supply and measurement sequence according to the measurement purpose, it is possible to provide an analysis function for a predetermined use. As another application example of these combinations, three analysis units of the same type can be arranged. For example, three micro analyzers of the same type are arranged and measured at the same time to improve the reliability of measured values, or if a failure occurs, the next analyzer is used to extend the life of the entire device. it can.

First, the case where the analyzing section 76 is used as a residual chlorine meter will be described. The analysis unit 76 includes the reagent mixing unit 20
1 and a measurement analysis unit 202. Reagent mixing section 2
The detailed structure of No. 01 will be described with reference to FIG. Reagent mixing section 2
Numeral 01 has a two-layer structure of a silicon substrate 301 and a Pyrex glass cover 302, and is manufactured by a microfabrication technique. The substrate 301 is made of a high-purity silicon wafer in an inverted S shape by anisotropic etching, and has a slope 303 having a predetermined angle and a flat bottom 304.
Is formed.

Further, a plurality of rectangular through holes 306, 307, 308, and 30 are also anisotropically etched from the back surface.
9 and mesh holes 310 in which fine holes of several tens of μm are arranged in a mesh at a pitch of 100 to 200 μm. The plurality of holes are connected by the flow path on the surface. The cover 302 is anodically bonded to the surface of the substrate 301 (anodic bonding).
It is joined by. Bonding of both is performed by applying a predetermined voltage in a high-temperature vacuum while maintaining the wafer size.

A plurality of types of liquids (sample water 71, reagent 82, cleaning liquid 86, reference liquid 89) are selectively supplied from the three-dimensional motherboard 101, the reference water 86 is supplied to the through hole 306, and the reference water 86 is supplied to the through hole 307. The cleaning liquid 89, the sample water 71 is supplied to the through hole 308, and the reagent 82 is supplied to the mesh hole 310. The supplied liquid flows through the flow path 305 and is guided to the cell portion 311 which is a linear part in the flow path, and is discharged to the three-dimensional mother board 101 through the through hole 309.

In the case of the residual chlorine measurement, the sample water 71 and the reagent 82 are supplied at a predetermined flow ratio while the cleaning liquid 86 and the reference water 89 are stopped, and are mixed in the flow path 305. At this time, reagent 8
2 is injected into the sample water 71 through the mesh hole 310. Therefore, since the reagent 82 is finely and uniformly injected into the sample water, it diffuses in a short time, and performs a color-forming reaction corresponding to the residual chlorine concentration. The colored reaction solution 312 is stored in the cell section 311.
And the degree of color development is optically measured. During measurement, the fluid is temporarily stopped to stabilize the measured value. After the measurement, the reaction solution 312 is discharged from the through hole 309.

When calibrating the sensitivity or the zero point, instead of the sample water 71, the reference solution 8 in which the chlorine concentration is measured in advance is used.
9 is supplied, measurement is performed in the same procedure, and the measured values are corrected using the measured values as reference values. The cleaning liquid 86 is supplied and washed in accordance with a predetermined cycle or the degree of contamination in order to remove mineral or vegetable stains in the reagent mixing section 201 (particularly, the cell section 311).

Returning to FIGS. 9A and 9B, the measurement / analysis unit 2
02 will be described. The measurement / analysis unit 202 includes a light emitting element 203 composed of an LED or a laser diode, and condenses light from the light emitting element 203 to form a slope 3 of the cell unit 311.
A lens system 204 for collecting light and a light receiving element 205 for monitoring a change in light amount are arranged at 03. The cell unit 3
The light 206 transmitted through the inside 11 is reflected on the slope 303 ′ opposite the slope 303 and returns to the measurement and analysis unit 202.

Light receiving element 2 for measuring the amount of light 207
08 is arranged in a part of the measurement and analysis unit 202. These light emitting element 203, light receiving elements 205 and 208, lens system 2
The cell part 311 and the cell part 311 are held by an analysis part base 209 in order to fix their relative positions, and the analysis part base 209 is held detachably on the three-dimensional motherboard 101.

As for the other analysis units (chromaticity and turbidity), the details of the analysis units are omitted, but the mounting dimensions and the arrangement of the flow paths are modularized and common.

In this embodiment, the valves and the pumps are arranged on the three-dimensional mother board. However, these can be formed on the same silicon wafer together with the reagent mixing section by the further progress of microfabrication. Yes, it is a means of further downsizing the analyzer. Even in this case, modularizing each analysis unit has a great effect on overall standardization and expandability of functions.

In FIG. 10, the motherboard 1 of the present invention is shown.
The details of the flow path 313 inside 01 will be described. The fluid 314 flows through a flow path in the motherboard integrally formed by the optical shaping method. The liquid contact portion 315 on the inner surface of the flow path is not eroded by the fluid, and it is necessary to improve corrosion resistance or antibacterial property in order to suppress the generation of microorganisms and bacteria in the flow path. Therefore, after a corrosion-resistant material (fluororesin, liquid rubber, electroless plating, etc.) or an antibacterial material (silver, copper oxide, titanium oxide, etc.) 316 is flowed evenly through the flow path, heat is applied to a thickness of several μm. Coating was performed to expand the range of applicable fluids arising from material limitations of stereolithography.

[0047]

As described above, according to the present invention, a flow path which is not eroded by a fluid, suppresses the generation of microorganisms and bacteria in the flow path, and has excellent corrosion resistance or antibacterial property can be realized.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an online water quality meter system according to an embodiment of the present invention.

FIG. 2 is a diagram showing an example of an analyzer installed in an online water quality meter system according to an embodiment of the present invention.

FIG. 3 is an internal configuration diagram showing an embodiment of the analyzer of the present invention.

FIG. 4 is a diagram showing an installation example of an embodiment of the analyzer of the present invention.

FIG. 5 is a configuration diagram showing internal details of an embodiment of the analyzer of the present invention.

FIG. 6 is an external view of a channel motherboard of the analyzer of the present invention.

FIG. 7 is a three-dimensional view of the internal flow path of FIG. 6;

FIG. 8 is a sectional structural view of an analysis unit of the present invention.

FIGS. 9A and 9B are a plan view and a sectional view of a reagent mixing section of the present invention.

10A and 10B are detailed views of a flow path inside a motherboard of the present invention.

[Explanation of symbols]

1 ... water purification facility, 2 ... water distribution facility, 3 ... management center, 4 ... water distribution main pipe, 5 ... water distribution system main pipe, 6 ... water supply company side water pipe,
7: Consumer side water pipe, 8: Water quality meter, 9: Water meter, 1
0 ... shut-off valve, 11 ... water distribution equipment, 12 ... water tap, 13 ... sample introduction part, 14a, 14b, 14c, 201 ... reagent mixing part, 15, 16, 17, 76, 77, 78 ... analysis part, 1
8: signal processing / control unit, 19: output / transmission unit, 20: power supply unit, 21: wireless, 22: sample introduction pipe, 51: water distribution pipe,
52: drinking water, 53, 55, 57, 61: piping, 54,
58, 62: manual valve, 56: pressure reducing valve, 59: drain pipe, 6
0: drain, 63: filter, 64: analyzer body, 6
5, 68, 70, 72, 94, 305, 313 ... flow path,
66: deaeration tank, 67: bubble, 69, 73, 75a, 75
b, 75c, 83, 85a, 85b, 85c, 88a,
88b, 88c, 91a, 91b, 91c, 93: solenoid valve, 71: sample water, 74, 84: metering pump, 79, 8
0, 81: cartridge, 82, 86, 89: liquid, 8
7, 90: pump, 92: waste, 95: collection container, 10
1 ... three-dimensional motherboard, 102 ... channel opening, 103
... Screw hole, 202 ... Measurement / analysis unit, 203 ... Light emitting element, 2
04: lens system, 205, 208: light receiving element, 206,
207: light, 209: analysis base, 301: substrate, 3
02: cover, 303: slope, 304: bottom, 306,
307, 308, 309: through hole, 310: mesh hole, 311: cell part, 312: reaction liquid, 314: fluid,
315: Liquid contact part, 316: Corrosion resistant material or antibacterial material.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) C02F 1/50 531 C02F 1/50 531F

Claims (5)

[Claims] 1. A water purification facility for purifying raw water such as rivers, lakes, wells and the like into water suitable for drinking, a water distribution facility for supplying purified water obtained by the water purification facility to consumers, and a water distribution state of the water distribution facility. And a management center that plays a role of monitoring and feeding back to the operation control system of the water purification facility and the distribution facility as necessary, a water supply company side distribution pipe that is a part of the water distribution facility, and connected to the distribution pipe. In a water supply distribution system including a customer-side water distribution facility and a distribution pipe, and a water quality meter that measures the quality of water in the distribution pipe, a flow path in the water quality meter is set to 3
An on-line water quality meter comprising a three-dimensional integrally formed motherboard, wherein a liquid contact portion on an inner surface of a flow passage in the motherboard is formed of a corrosion-resistant material or an antibacterial material. 2. The on-line water quality meter according to claim 1, wherein the liquid contact portion on the inner surface of the flow channel is coated with a corrosion-resistant material or an antibacterial material. 3. An on-line water quality meter according to claim 2, wherein the liquid contact portion on the inner surface of the flow path of the fluid circuit having a plurality of flow paths having a diameter of 4 mm or less is coated with a corrosion-resistant material or an antibacterial material. 4. A corrosion-resistant material or an antibacterial material according to claim 2, wherein a liquid contact portion on the inner surface of the flow path of the fluid circuit containing a plurality of flow paths having a diameter of 4 mm or less in a mother board integrally formed by three-dimensional stereolithography is formed. Online water quality meter characterized by coating with. 5. The method according to claim 1, wherein at least the corrosion-resistant material is a fluororesin, a liquid rubber, or electroless plating, and the antibacterial material is silver, copper oxide, or the like.
An online water quality meter characterized by selecting and coating one of the titanium oxides.