JP2003329585A - Ozone concentration meter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ozone concentration meter capable of achieving compactness even in the case that a low concentration of ozone is to be measured and measuring a wide range of ozone concentrations from a low concentration to a high concentration. <P>SOLUTION: In an ozone water concentration meter 31, ultraviolet rays are irradiated at an angle of incidence of 18° from an ultraviolet irradiation window 7 toward a side 4-3 of an ultraviolet reflecting surface 5 in the inner surface of a measuring cell 32. Ultraviolet rays similarly and sequentially multiply reflected at a side 4-5 and a side 4-2 and transmitted through an ultraviolet transmitting window 8 are received by an ultraviolet sensor 35 for measuring a low concentration of ozone. The attenuation ratio of the transmitted ultraviolet rays transmitted through ozone water is of a previously set upper limit value or less at the ultraviolet sensor 35 for measuring a low concentration of ozone, the concentration of ozone water is computed by Lambert-Beer's law and displayed on a concentration display 23. In the case that it is of the upper limit value or more, the concentration of ozone exceeds the measurement range of a low concentration of ozone, and the concentration of ozone water is computed on the basis of the results of light reception at an ultraviolet sensor 34 for measuring a high concentration of ozone and displayed on the concentration display 23. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an ozone concentration meter.

[0002]

2. Description of the Related Art An ozone water concentration meter based on the ultraviolet absorption method utilizes the principle that ozone absorbs ultraviolet rays. Ozone water containing ozone and reference water not containing ozone are alternately placed in a measuring cell. The ozone concentration of ozone water is obtained by passing water. The structure of a conventional ozone water concentration meter will be described with reference to FIG. 8. Reference numeral a is an ultraviolet lamp as a light source, and a measuring cell b is arranged in the vicinity of the ultraviolet lamp a. An ultraviolet sensor c as a light receiver is arranged at a position facing the ultraviolet lamp a on the rear side of the measuring cell b.

[0003]

However, the range of ozone concentration measured by the conventional ozone water densitometer is determined by the length (L) of the measuring cell that defines the optical path length of the ultraviolet ray passing through the reference water or the ozone water. It is decided uniquely. That is, when low-concentration ozone is to be measured, there is a problem that the measurement cell needs to be long in order to increase the absolute amount of absorption of ultraviolet rays, resulting in an increase in size. Further, there is also a device in which a mirror is provided on the opposite side of the measurement cell and the light (ultraviolet ray) reflected by the mirror is received through a front half mirror, but the structure is complicated and the number of parts is large, resulting in high cost. There is a problem that becomes. The present invention has been made to solve the above-mentioned problems, and can be downsized even when low-concentration ozone is measured, and the ozone concentration can measure a wide range of ozone concentrations from low to high. It is intended to provide a total.

[0004]

The ozone concentration meter according to claim 1 for achieving the above object is a supply pipe capable of alternately supplying an ozone-containing fluid containing ozone and a reference fluid not containing ozone. An ozone-containing fluid, which is provided with a channel and a measuring cell for receiving the supplied ozone-containing fluid or the reference fluid and receiving from the light source the light that has passed through the ozone-containing fluid or the reference fluid by a light receiver to measure the ultraviolet absorbance. In an ozone densitometer for alternately supplying a reference fluid and a reference fluid to a measurement cell to determine the ozone concentration of an ozone-containing fluid, the inner surface of the measurement cell is formed into a regular polygonal cross section having an odd number of 5 or more, and the regular polygonal shape. Provide a light source on any one of the sides of
It is characterized in that the light from the light source is multiple-reflected in the measurement cell on a plurality of sides of the inner surface of the measurement cell and is received by the first light receiver provided on the other side.

Further, the ozone concentration meter according to claim 2 is
The structure according to claim 1, wherein the second light receiver is provided on any one of a plurality of sides which are reflection surfaces other than the side provided with the light source and the side provided with the first light receiver. It is characterized by

According to a third aspect of the present invention, in the ozone concentration meter according to the second aspect, when the ultraviolet absorption of the ozone-containing fluid in the first light receiver is within a preset upper limit, The ozone concentration is calculated on the basis of the ultraviolet absorption of the ozone-containing fluid in the first light receiver, while if the ultraviolet absorption of the ozone-containing fluid in the first light receiver is not less than the preset upper limit, The second feature is that the ozone concentration is calculated based on the ultraviolet absorbance of the ozone-containing fluid in the second light receiver.

[0007]

According to the ozone densitometer of claim 1, the light (ultraviolet ray) from the light source provided on any one of the sides of the regular polygon on the inner surface of the measuring cell is irradiated on the inner surface of the measuring cell. Since the inside of the measurement cell is multiple-reflected by a plurality of sides and the light is received by the first light receiver provided on the other side, the optical path length can be made long in a limited space, and a long optical path length is required. A compact ozone concentration meter that can measure low-concentration ozone can be realized.

According to the ozone concentration meter of claim 2,
Since the second light receiver is provided on any one of a plurality of sides that are reflection surfaces other than the side on which the light source is provided and the side on which the first light receiver is provided, the optical path length is determined by one ozone concentration meter. You can set multiple. That is, it is possible to provide an ozone densitometer having a wide range of measurement of low concentration and higher concentration and having high cost performance.

According to the ozone concentration meter of claim 3,
When the ultraviolet absorption of the ozone-containing fluid in the first light receiver is within the preset upper limit value, the ozone concentration is calculated based on the ultraviolet absorption of the ozone-containing fluid in the first light receiver, When the ultraviolet absorption of the ozone-containing fluid in the first light receiver is equal to or higher than the preset upper limit value, the ozone concentration is calculated based on the ultraviolet absorption of the ozone-containing fluid in the second light receiver, and a plurality of ozone concentrations are calculated. Since the light receiving device is adapted to the ozone concentration and used properly, a highly accurate ozone concentration meter with high resolution can be provided.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) A first embodiment in which the present invention is applied to an ozone water concentration meter will be described with reference to the accompanying drawings. 1 is a schematic block diagram of an ozone water concentration meter 1 according to the first embodiment, FIG. 2 is a cross-sectional view of a measuring cell 2, and FIG. 3 is a timing chart at the time of measurement. The inner surface of the circular measuring cell 2 is formed into a regular pentagon.
Each of the regular pentagonal sides 4-1 to 4-5 on the inner surface of the measurement cell 2 is
It has an ultraviolet reflecting surface 5. An ultraviolet irradiation window 7 in which the ultraviolet transparent glass 6 is watertightly fitted is formed on the side 4-1. On the side 4-4, an ultraviolet transmitting window 8 in which the ultraviolet transmitting glass 6 is watertightly fitted is formed.

A water supply port 9 for supplying reference water or ozone water is formed on the upper surface of the measuring cell 2, and a drain port 10 is formed on the lower surface. The drainage port 10 is formed to have a smaller diameter than the water supply port 9. Furthermore, the overflow port 1 is provided on the upper surface of the measuring cell 2.
1 is formed.

A water supply line including an ozone water line 12 and a reference water line 13 is connected to the water supply port 9. Electromagnetic on-off valves 14 and 15 are provided in the ozone water conduit 12 and the reference water conduit 13, respectively, so that either ozone water or reference water can be supplied from the water supply port 9 into the measurement cell 2. Further, a drainage pipe 16 is provided in the drainage port 10. An overflow pipe line 17 is piped to the overflow port 11, and the tip of the overflow pipe line 17 is connected to the drainage line 16. Further, an atmosphere open pipe line 19 having an electromagnetic opening / closing valve 18 is connected to the middle of the overflow pipe line 17.

In the measuring cell 2, an ultraviolet lamp 20 is arranged facing the ultraviolet irradiation window 7, and an ultraviolet sensor 21 is arranged facing the ultraviolet transmission window 8. The electromagnetic on-off valves 14, 15, 18 and the ultraviolet sensor 21 are connected to a control circuit 22, respectively. The control circuit 22 executes the stored measurement processing program to cause the electromagnetic opening / closing valve 1 to
4, 15 and 18 are turned on and off at a predetermined timing, and the attenuation rate of the ultraviolet transmitted light that passes through the ozone water (ultraviolet light is determined based on the intensity of the transmitted light of the reference water and the ozone water measured by the ultraviolet sensor 21). Absorbance) is calculated, and the ozone water concentration is calculated based on the Lambert-Beer's law and displayed on the concentration display 23.

Further, the ultraviolet rays from the ultraviolet lamp 20 are
As shown by the central optical path R, the ultraviolet ray irradiation window 7 irradiates the ultraviolet ray reflecting surface 5 on the opposite side 4-3 at an incident angle of 18 degrees. From the relationship of incident angle = reflection angle, the ultraviolet rays reflected by the ultraviolet reflecting surface 5 on the side 4-3 are incident on the ultraviolet reflecting surface 5 on the side 4-5 at an incident angle of 18 degrees. Similarly, side 4
Ultraviolet rays that have been multiple-reflected in the measurement cell 2 in the order of -5 and side 4-2 are transmitted through the ultraviolet transmission window 8 and received by the ultraviolet sensor 21.

A procedure for measuring the concentration of ozone water by the ozone water concentration meter 1 having the above-mentioned configuration will be described with reference to the timing chart of FIG. First, the ultraviolet lamp 20 is turned on, and then the measurement switch is turned on to start the measurement. When the measurement switch is turned on, the electromagnetic on-off valve 15 is opened and the reference water is supplied from the reference water pipe line 13 to the measurement cell 2. At this time, the drainage port 10
The amount of drainage from the river is less than the amount of water supply. Therefore, in the measuring cell 2, the water level of the reference water gradually rises, overflows from the overflow port 11 and flows out to the overflow conduit 17. In the state where the water flow is generated as described above, the intensity of the transmitted light of the ultraviolet rays that are multiple-reflected in the measurement cell 2 and transmitted through the reference water as described above is measured by the ultraviolet sensor 21 and output to the control circuit 22. To do.

When the measurement of the transmitted light with respect to the reference water is completed, the electromagnetic opening / closing valve 15 is closed to stop the supply of the reference water, and the electromagnetic opening / closing valve 18 of the atmosphere opening pipe line 19 is opened to connect the overflow pipe line 17, that is, this pipe. The overflow port 11 is opened to the atmosphere, and all the reference water in the measuring cell 2 is drained. When the drainage is completed, the electromagnetic opening / closing valve 18 is closed, and at the same time, the electromagnetic opening / closing valve 14 is opened, and ozone water is supplied to the measuring cell 2 from the ozone water pipe line 12. With the ozone water overflowing from the overflow port 11, the intensity of the transmitted light of the ultraviolet rays that pass through the ozone water is measured and output to the control circuit 22 as in the case of the reference water. The control circuit 22 calculates the attenuation rate of the ultraviolet transmitted light that passes through the ozone water based on the intensity of the transmitted light of the reference water and the intensity of the transmitted light of the ozone water, and based on this, the Lambert-Beer's The ozone water concentration is calculated according to the law and displayed on the concentration display 23. When the measurement of the transmitted light to the ozone water is completed, the electromagnetic opening / closing valve 14 is closed to stop the supply of ozone water, and the electromagnetic opening / closing valve 18 of the atmosphere opening conduit 19 is opened to open the overflow port 11 to the atmosphere. , All ozone water in the measuring cell 2 is drained.

The ozone water concentration meter 1 comprises an ultraviolet lamp 2
The ultraviolet ray from 0 is irradiated from the ultraviolet ray irradiation window 7 toward the ultraviolet ray reflecting surface 5 on the side 4-3 of the inner surface of the measuring cell 2 at an incident angle of 18 degrees, and thereafter, in the same manner, the side 4-5 and the side 4-2. The ultraviolet rays transmitted through the measurement cell 2 in the order of
Since the ultraviolet ray is transmitted through and received by the ultraviolet sensor 21, the optical path length of the ultraviolet ray passing through the ozone water can be lengthened, so that the measuring cell 2 capable of measuring the low ozone concentration becomes small, and the ozone water concentration meter 1 Can be made smaller.

(Second Embodiment) FIG. 4 is a schematic block diagram of an ozone water concentration meter 31 according to a second embodiment of the present invention. Ozone water concentration meter 3 according to the second embodiment
The basic configuration of No. 1 is the same as that of the first embodiment. Therefore, the same components as those of the ozone water concentration meter 1 according to the first embodiment described above are designated by the same reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 5, the measuring cell 32 of the ozone water concentration meter 31 according to the second embodiment has an ultraviolet transmitting glass 6 in which the ultraviolet transmitting glass 6 is watertightly fitted to the side 4-3 of the inner surface. The point that the window 33 is formed is different from the configuration of the measurement cell 1 of the first embodiment. An ultraviolet sensor 34 for measuring high-concentration ozone is arranged facing the ultraviolet transmission window 33, and an ultraviolet sensor 35 for measuring low-concentration ozone is arranged facing the ultraviolet transmission window 8. The ultraviolet sensors 34 and 35 are connected to the control circuit 22 via the sensor signal changeover switch 36.

A procedure for measuring the ozone water concentration of the ozone water concentration meter 31 having the above-mentioned configuration will be described with reference to the timing chart of FIG. Similarly to the first embodiment, the reference water is supplied to the measurement cell 32, and the intensity of the transmitted light of the ultraviolet light that passes through the reference water is measured. At this time, the sensor signal changeover switch 36 is switched to the UV sensor 35 side for measuring low-concentration ozone at the L contact, so that the UV sensor 3 is switched.
The intensity of the transmitted light of the ultraviolet ray measured by 5 is output to the control circuit 22. Then, the sensor signal changeover switch 36
The H contact is switched to the UV sensor 34 side for measuring high-concentration ozone, and the intensity of the UV transmitted light measured by the UV sensor 34 is output to the control circuit 22. After this measurement, the sensor signal changeover switch 36 is changed over again to the UV sensor 35 side for measuring the low concentration ozone at the L contact.

Subsequently, when the drainage of the reference water from the measuring cell 32 is completed, the electromagnetic opening / closing valve 18 is closed, and at the same time, the electromagnetic opening / closing valve 1 is closed.
4 is opened, and ozone water is supplied from the ozone water conduit 12 to the measuring cell 2. Similar to the case of the reference water, the intensity of the transmitted light of the ultraviolet rays that pass through the ozone water is measured. At this time,
Since the sensor signal changeover switch 36 is switched to the UV sensor 35 side for measuring low-concentration ozone at the L contact, the intensity of the UV transmitted light measured by the UV sensor 35 is output to the control circuit 22. Subsequently, the sensor signal changeover switch 36 is changed over to the UV sensor 34 side for measuring the high concentration ozone of the H contact, and the intensity of the transmitted light of the UV rays measured by the UV sensor 34 is output to the control circuit 22. After this measurement, the sensor signal changeover switch 36 is changed over again to the UV sensor 35 side for measuring the low concentration ozone at the L contact.

In the control circuit 22, the ultraviolet transmitted light transmitted through the ozone water by the ultraviolet sensor 35 is attenuated based on the intensity of the transmitted light of the reference water and the ozone water measured by the ultraviolet sensor 35 for measuring low-concentration ozone. Calculate the percentage. Further, based on the intensity of the transmitted light of the reference water and the ozone water measured by the ultraviolet sensor 34 for measuring high-concentration ozone, the attenuation rate of the ultraviolet transmitted light transmitted through the ozone water by the ultraviolet sensor 34 is calculated. Then, if the attenuation rate of the ultraviolet transmitted light that transmits the ozone water by the ultraviolet sensor 35 for measuring low-concentration ozone is equal to or less than the preset upper limit value shown in the graph of FIG. 7, according to the Lambert-Beer law. The ozone water concentration determined by the attenuation rate is calculated and displayed on the concentration display 23.

When the attenuation rate of the ultraviolet transmitted light which transmits the ozone water by the ultraviolet sensor 35 for measuring low concentration ozone is more than the upper limit value shown in the graph of FIG. 7, the ozone concentration is in the range of low concentration ozone measurement. In this case, the ozone water concentration determined by the attenuation rate of the ultraviolet transmitted light that passes through the ozone water by the ultraviolet sensor 34 for measuring high-concentration ozone is calculated and displayed on the concentration display 23.

As described above, the ozone water concentration meter 31 of the second embodiment is further divided into the side 4-3 other than the side provided with the ultraviolet irradiation window 7 and the ultraviolet transmission window 8 on the inner surface of the measurement cell 32. The UV transmission window 33 is provided, the UV sensor 34 for measuring high concentration ozone is arranged facing the UV transmission window 33, and the UV sensor 35 for measuring low concentration ozone is arranged facing the UV transmission window 8. Therefore, it is possible to set a plurality of optical path lengths with one ozone water concentration meter, and it is possible to provide an ozone water concentration meter having a wide measurement range of low concentration and high concentration and high cost performance.

If the attenuation rate of the ultraviolet transmitted light that passes through the ozone water by the ultraviolet sensor 35 for measuring low-concentration ozone is within a preset upper limit value, the attenuation rate of the ultraviolet transmitted light by the ultraviolet sensor 35 is set to the attenuation rate. On the other hand, when the ozone water concentration is calculated based on the above, on the other hand, when it is equal to or higher than the upper limit value, the ozone water concentration is calculated based on the attenuation ratio of the ultraviolet transmitted light by the ultraviolet sensor 34 for measuring high-concentration ozone. A highly accurate ozone water concentration meter can be provided.

In the first and second embodiments, the ozone concentration of ozone water is measured, but the ozone concentration of ozone contained in the gas may be measured. Further, although the inner surface of the measurement cell has a regular pentagonal cross section, it may have a regular polygonal cross section having an odd number of 5 or more, such as a regular heptagonal cross section and a regular nonagonal cross section.

[Brief description of drawings]

FIG. 1 is a schematic block diagram of an ozone water concentration meter according to a first embodiment.

FIG. 2 is a cross-sectional view of a measuring cell.

FIG. 3 is a timing chart at the time of measurement.

FIG. 4 is a schematic block diagram of an ozone water concentration meter according to a second embodiment.

FIG. 5 is a cross-sectional view of a measuring cell.

FIG. 6 is a timing chart at the time of measurement.

FIG. 7 is a graph showing the relationship between the attenuation rate of ultraviolet transmitted light and the concentration of ozone water.

FIG. 8 is a block diagram showing a conventional example.

[Explanation of symbols]

1,31 ... Ozone water concentration meter 2, 32 ... Measuring cell 4-1 to 4-5 ... Regular pentagonal side of inner surface of measuring cell 5 ... UV reflective surface 7 ... UV irradiation window 8 ... UV transparent window 12 ... Ozone water pipeline 13 ... Standard water line 20 ... UV lamp 21, 34, 35 ... UV sensor 22 ... Control circuit 23 ... Concentration indicator 33 ... UV transparent window 36 ... Sensor signal changeover switch R ... central optical path

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[Procedure amendment]

[Submission date] May 10, 2002 (2002.5.1)
0)

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 3

[Correction method] Change

[Correction content]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Correction content]

According to a third aspect of the present invention, in the ozone concentration meter according to the second aspect, when the ultraviolet absorption of the ozone-containing fluid in the first light receiver is within a preset upper limit, calculating the ozone concentration based on UV absorbance of an ozone-containing fluid at the first light receiver, whereas, when the UV absorbance of the ozone-containing fluid at the first light receiver is more than the upper limit value set in advance, the It is characterized in that the ozone concentration is calculated based on the ultraviolet absorbance of the ozone-containing fluid in the second light receiver.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0009

[Correction method] Change

[Correction content]

According to the ozone concentration meter of claim 3,
When the ultraviolet absorption of the ozone-containing fluid in the first light receiver is within the preset upper limit value, the ozone concentration is calculated based on the ultraviolet absorption of the ozone-containing fluid in the first light receiver, in the case of more than the upper limit value of UV absorbance preset ozone-containing fluid at the first light receiver, so as to calculate the ozone concentration based on UV absorbance of an ozone-containing fluid at the second photodetector, Since a plurality of light receivers are adapted to the ozone concentration and used properly, it is possible to provide a highly accurate ozone concentration meter with high resolution.

Claims (3)

[Claims] 1. A supply pipeline capable of alternately supplying an ozone-containing fluid containing ozone and a reference fluid containing no ozone, and an ozone-containing fluid or reference supplied from the light source by feeding the supplied ozone-containing fluid or reference fluid. An ozone densitometer equipped with a measuring cell for measuring the UV absorbance by receiving light that has passed through the fluid with a light receiver, and supplying the ozone-containing fluid and the reference fluid alternately to the measuring cell to obtain the ozone concentration of the ozone-containing fluid. In, while forming the inner surface of the measurement cell into a regular polygonal cross section having an odd number of 5 or more, a light source is provided on any one of the sides of the regular polygon, and light from the light source is supplied to the inner surface of the measurement cell. Multiple reflections inside the measurement cell on multiple sides, and the first on the other side
An ozone densitometer, characterized in that it is configured to receive light by the above-mentioned light receiver. 2. A second photodetector is provided on any one of a plurality of sides that are reflection surfaces other than the side on which the light source is provided and the side on which the first photodetector is provided. The ozone concentration meter according to claim 1. 3. When the ultraviolet absorption of the ozone-containing fluid in the first light receiver is within a preset upper limit, the ozone concentration is determined based on the ultraviolet absorption of the ozone-containing fluid in the first light receiver. On the other hand, when the ultraviolet absorption of the ozone-containing fluid in the first light receiver is equal to or more than the preset upper limit value, the ozone concentration is calculated based on the ultraviolet absorption of the ozone-containing fluid in the second light receiver. The ozone concentration meter according to claim 2, wherein the ozone concentration meter is calculated.