JP2012173273A - Ozone concentration measurement device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ozone concentration measurement device capable of obtaining a correct measurement value using a nitride-based deep ultraviolet semi-conductor element and eliminating damage to the device, since when a sample gas passing through a measurement cell moves a long transmission distance, ozone repeatedly irradiated during transmission by ultraviolet rays do not allow correct ozone concentration measurement.SOLUTION: Suppression of re-ozonization and correct ozone concentration measurement can be realized by: using a solid light emitting element for emitting an ultraviolet ray including the wavelengths of 200 nm to 320 nm; providing a sample gas measurement part constituted by a gas emission part for inhaling the sample gas at a position opposed to a gas injection part for blowing the sample gas; providing a mechanism for instantaneously passing the sample gas; preventing disorder of the gas; and shortening a transmission period of time.

Description

  The present invention relates to an ultraviolet absorption ozone concentration measuring apparatus using a solid light emitting element such as a nitride-based deep ultraviolet semiconductor light emitting element.

  According to Non-Patent Document 1, which is a reference book explaining ultraviolet rays, ozone has absorption bands called Chapuis band (850 nm to 440 nm), Huggins band (360 nm to 300 nm), and Hartley band (200 to 320 nm). The present invention relates to an ultraviolet absorption ozone concentration measurement using ultraviolet rays in the Hartley band (200 to 320 nm). Three types of active oxygen (O (P), O (D), and O (S)) having different energy levels are generated depending on the wavelength of ultraviolet rays (200 to 320 nm) emitted to the Hartley band ozone. The magnitude of the energy level is O (P) <O (D) <O (S). When ultraviolet rays having a wavelength of 266 nm (4.66 eV) or more are emitted to O3 (ozone, the same applies hereinafter), only active oxygen O (D) is generated. At a wavelength of 320 nm (3.87 eV), the amount of O (D) generated is reduced but still generated. O (S) is generated at a wavelength of less than 266 nm (4.66 eV) in O3, and O (D) and O (S) are mixedly generated. When the wavelength is 237 nm (5.23 eV), O (D) is no longer generated and only O (S) is generated, and the amount of O (S) generated increases from the wavelength 200 nm (6.20 eV).

  Note that active oxygen O (P) is not generated unless it is ultraviolet light with O3 of 463 nm or less (2.68 eV or more). Since the present invention measures the ozone concentration in the Hartley band, O (D) and O (S) are taken up.

In summary,
1) O3 + wavelength (320 nm to 266 nm) → O (D) + O2 (oxygen molecule, the same applies hereinafter),
2) O3 + wavelength (less than 266 nm to 237 nm) → O (S, D) + O2,
3) O3 + wavelength (less than 237 nm to 200 nm) → O (S) + O2

  O (D) and O (S) cause oxidation. By utilizing this oxidation action, it is used for forming the oxide film thickness in the semiconductor manufacturing process. For example, an oxide film thickness is formed on the silicon surface to provide a gate insulating film on the silicon surface. It can also be used to remove organic substances on the silicon surface using the generated active oxygen.

  The absorbance of ozone changes depending on the wavelength. This absorptance can be measured by the absorption cross section of ozone as shown in FIG. FIG. 7 is an excerpt from the non-patent document 2, which is a reference book, and shows a graph of the relationship between the ozone absorption cross section at a constant temperature and the ultraviolet wavelength region. It can be judged from the graph of FIG. 7 how efficiently the wavelength region is absorbed by ozone. For example, a single wavelength of 254 nm (4.88 eV), which is a mercury spectral line, is coincidental, but is in the vicinity of a wavelength that is efficiently absorbed by ozone.

  When the value of the absorption cross section of ozone is large, the wavelength is efficiently absorbed by ozone. Since the wavelength of 255 nm is the peak value of the absorption cross section of ozone, it becomes the maximum ozone absorption wavelength. This means that in the Hartley band ozone absorption wavelength band (200 to 320 nm), not only the vicinity of the wavelength of 255 nm (4.86 eV) is absorbed by ozone, but there is a light absorption effect throughout the Hartley band. .

  Ultraviolet absorption ozone measurement measures the radiation output intensity I of the wavelength before being absorbed by ozone and the radiation output intensity O after being absorbed by ozone, and the amount of absorbed ultraviolet light is obtained. From the Lambert-Beer law It uses the principle of determining the ozone concentration.

  When the concentration is measured by the ultraviolet absorption method, the sample to be measured is obtained by Equation 1 of Lambert-Beer's law. The radiation output intensity of the ultraviolet light that has passed through the sample gas is O, the radiation output intensity I of the incident light before passing through the sample gas, the absorption coefficient of ozone at the wavelength ε (the ozone absorption coefficient ε is the absorption of ozone by each wavelength) The value of the coefficient is determined.) When the ozone concentration of the sample gas is c and the optical path length of the light when the ultraviolet rays pass through the sample gas is L, Equation 1 is as follows. JIS B 7957 Automatic measuring instrument for ozone and oxidant in the atmosphere Appendix 2 (normative) describes the method for pricing ozone concentration using an ultraviolet absorptiometer, and the ozone concentration using the formula shown here Can be calculated, but the algorithm is basically the same as Equation 1 below.

  Around 1992, ozone concentration was measured by using a low-pressure mercury lamp instead of the conventional wet method. Unlike wet methods, low-pressure mercury lamps do not use chemicals, are easy to maintain, and have high measurement sensitivity, so the use of low-pressure mercury lamps for ozone concentration measurement has increased.

  As shown in Patent Document 1, the ozone concentration measurement using a low-pressure mercury lamp uses ultraviolet light having a single wavelength of 254 nm emitted from a low-pressure mercury lamp using vacuum discharge. This method is advantageous in that a wavelength of 254 nm that is efficiently absorbed by ozone can be used, and that the wavelength is a single wavelength. However, because it is a low-pressure mercury lamp that uses vacuum discharge, the difference between the upper and lower limits of the radiant output intensity in time units becomes large, and correction is always necessary to obtain the correct ozone concentration. In addition, the low-pressure mercury lamp deteriorates in about 5000 hours and has a weak point that must be replaced.

  This weak point led to an operational problem in that it was necessary to go to uninhabited islands in order to replace the low-pressure mercury lamp, especially for automatic ozone concentration measuring devices installed on uninhabited islands.

  Furthermore, because the low-pressure mercury lamp contains mercury, it is difficult to dispose of it and the impact on the environment is large.

  For these problems, Patent Document 2 discloses a method of using a diamond ultraviolet light emitting element instead of a low-pressure mercury lamp. By using a diamond ultraviolet light emitting element, it took time to stabilize the emission intensity, which was a problem in measuring the UV absorption ozone concentration when using a low-pressure mercury lamp, and the emission intensity flickered. Has been resolved.

  In the method of Patent Document 2, measurement errors caused by the formation of an oxide film due to the action of O (S) and O (D) on the components of a measuring instrument, particularly the light emitting element surface, and re-ozone during measurement Did not take into account the effects of

To solve these problems, the method of Patent Document 3 uses a nitride-based deep ultraviolet semiconductor device as a light-emitting device, forms an oxide film on which O (S) and O (D) act, and re-ozonization during measurement. We have proposed an ozone concentration measurement device that takes into account the method of avoiding the effects of the effect as much as possible. In the embodiment, the nitride-based deep ultraviolet semiconductor element which is the invention of Patent Document 4 is employed.

JP-A-5-172743 Japanese Patent Laid-Open No. 2002-5826 Japanese Patent Application No. 2009-246024 International Publication Number WO2006 / 104063

Laboratory Chemistry Course Reaction and Speed Issued Maruzen Co., Ltd. Issued on February 5, 1993 Physical chemistry of the atmosphere Toshiaki Ogawa Publication place Tokyodo Publishing August 30, 1991

  However, in the method of Patent Document 3, the ozone in the sample gas passing through the measurement cell is decomposed into oxygen and active oxygen by ultraviolet rays, and then the active oxygen is combined with oxygen again to re-irradiate the ozone that has been re-ozonized. The problem is that ozone is not removed and an error occurs in the ozone measurement value. Further, it has been found from fluid measurement that the turbulence of the gas due to the minute distortion of the cell internal structure causes the active oxygen to remain in the cell. Due to the active oxygen, re-ozonization and deterioration of the apparatus occur.

  In Patent Document 3, in order to mitigate deterioration of the apparatus, the wavelength range of 250 to 260 nm where the value of the absorption cross section is large is set to be excluded. However, since the ultraviolet rays that pass through the ultraviolet converging tube that constitutes the measurement cell are concentrated and the irradiation energy is concentrated, the probability of re-ozonization during transmission is high, and the concentration of irradiation energy is reduced by the optical filter. It is estimated that it will damage the filter and adversely affect the filter life.

The present invention has been made to solve the above-described problems, and provides an ozone concentration measurement apparatus that uses a nitride-based deep ultraviolet semiconductor element to obtain a correct measurement value and eliminates damage to the apparatus. With the goal.

In order to solve the above problems, the present invention has the following features.

  An ozone concentration measuring apparatus according to the present invention includes a light emitting chamber mechanism provided with at least one solid light emitting element that emits ultraviolet light including a wavelength region of 200 nm to 320 nm, and a gas injection unit that blows out a sample gas with a sample gas measuring unit interposed therebetween. And at least one pair of gas discharge portions for sucking in the sample gas are provided, and the flow of sample gas in the sample gas measurement portion in which the ultraviolet rays from the light emission chamber mechanism travel from the gas injection portion to the gas discharge portion The three measurement chamber mechanisms having a structure that transmits light in a direction perpendicular to the direction and a light receiving chamber mechanism that includes an intensity sensor that receives ultraviolet light emitted from the measurement chamber mechanism and measures the radiation intensity thereof are removable. The intensity sensor receives the ultraviolet light that has passed through the measurement chamber mechanism without ozone, and the received light intensity value is The ozone concentration with zero set value acquisition means for zero value and the ozone zero value regarded as the received light value of the intensity sensor and the emission intensity when the ultraviolet light is transmitted through the sample gas measuring part in the state where the sample gas flows It has an ozone concentration calculation means for calculating

  When the pump sucks, the external atmosphere is sucked from the gas injection part and flows toward the gas discharge part at high speed. Ultraviolet rays are transmitted in a direction orthogonal to the flow of the sample gas. At this time, when ultraviolet rays hit ozone, they are consumed by energy that decomposes into oxygen and active oxygen, and are attenuated (absorbed). The pump must be installed on the suction side. In addition, it is preferable that the gas injection part and the gas discharge part are paired because distortion does not occur in the flow. A plurality of ports of the gas injection part and the gas discharge part are preferable, and the result of the ultraviolet rays passing through the plurality of flows while colliding with ozone is measured.

  In the present invention, the light emitting chamber mechanism is hermetically sealed in a vacuum or filled with an inert gas. By controlling the chopper drive power supply unit, the solid state light emitting element in the mechanism emits ultraviolet light intermittently, and the ultraviolet light becomes parallel light via a parallel lens. Next, a mechanism for reaching the optical filter and transmitting only the ultraviolet light having a single wavelength specified by the specification of the optical filter and entering the next measurement chamber mechanism is provided.

The optical filter in this case is preferably a band pass filter that transmits only a wavelength in a specified range. However, a long pass filter and a short pass filter may be combined. It goes without saying that this combination type is also included in the present invention. There are two types of optical filters: a reflection type that reflects light of a wavelength that is not used and an absorption type that is absorbed by the filter. In particular, in the case of the absorption type, there are concerns about damage due to temperature rise and deterioration of optical characteristics. However, since the ultraviolet energy of the present invention is weak, there is almost no influence on the deterioration of the optical filter. Therefore, either type can be used. In addition, the surface of the solid state light emitting device is usually protected by a lens, but this lens may be an integrated type of a parallel lens and an optical filter. Or you may arrange | position the lens which integrated the parallel lens and the optical filter in the boundary of a light emission chamber and a measurement chamber mechanism.

  The intermittent period of ultraviolet light emission of the chopper drive power supply unit in the present invention is a combination of a short period and a long period. The short cycle is a cycle in which ozone measurement is performed by blinking ultraviolet rays. Furthermore, it is predicted that the measured sample gas mixed with active oxygen will be sucked into the gas discharge part between the first short cycle and the second short cycle, when ultraviolet rays are irradiated in the first short cycle. Thus, an estimated gas discharge time (non-measurement time) for interrupting ultraviolet irradiation is provided. The long cycle is an interval obtained by combining the first short cycle and the expected gas discharge time. These two cycles are realized by computer control.

The reason for setting the expected gas discharge time and interrupting the measurement is to prevent the re-ozonized ozone from being measured again. Therefore, after ultraviolet rays separate ozone into oxygen and active oxygen, the time for discharging the ozone in which the active oxygen is combined with oxygen before the measurement becomes the expected gas discharge time. The computer calculates the flow rate of the sample gas relative to the distance between the gas inlet / outlet and predicts the discharge time. If this time is made sufficiently long, re-ozoneized ozone can be eliminated. Furthermore, the smaller the distance between the gas injection part and the gas discharge part, the better. This is because the earlier the exhaust, the lower the probability that the re-ozoneized ozone will be reabsorbed into ultraviolet light. This interval largely depends on the size of the solid state light emitting device. However, once the light is collected by the condenser lens before entering the parallel lens, the interval can be controlled. Although the timing setting for short and long cycles depends on the light output and the performance of the measurement component, it is possible to analyze the efficiency and safety from the information recorded through use and incorporate the mechanism to obtain the best execution conditions. Good.

In the present invention, the light receiving chamber mechanism is hermetically sealed in a vacuum or incapable gas filling state. The ultraviolet rays that have exited the measurement chamber mechanism are focused by a condensing lens provided in the light receiving chamber mechanism, and irradiated to the intensity sensor.

  Further, the zero set value acquisition means of the present invention temporarily seals the inside of the measurement chamber mechanism to block the intrusion of external air, and continuously irradiates ultraviolet rays from all the solid state light emitting elements used for measurement, whereby the measurement chamber mechanism Destroy the ozone inside. When all the ozone is destroyed, the received light intensity received by the intensity sensor does not change. Therefore, the received light intensity of the transmitted ultraviolet rays is measured at least twice, and the intensity sensor value when the intensity sensor value no longer changes is the received light intensity at zero ozone.

After the ozone is zero, the ultraviolet light is not absorbed, and therefore, the ultraviolet light is continuously irradiated until the measured value becomes constant based on the assumption that the received light intensity does not change. Until this measurement value becomes constant (reaches ozone zero), ozone destruction time may be shortened by joining elements used only during ozone destruction or increasing the output intensity of elements for concentration measurement. . However, after reaching ozone zero, the ozone zero intensity reference value must be obtained only by the elements participating in the measurement with the same output intensity as at the time of measurement. In consideration of the influence of noise, the number of comparisons until the measurement value is recognized as being unchanged is determined empirically by analyzing data recorded in the storage device of the computer. Moreover, in order to make it the same conditions as at the time of measurement, a step of measuring with intermittent light emission (short cycle) may be added to the final determination of the zero reference value. Note that the received light intensity of ozone zero can be regarded as the emission intensity (the initial intensity at which light is emitted from the element and has not yet been absorbed).

  Further, the ozone concentration calculation means in the present invention records the measurement value when the ultraviolet ray incident on the measurement chamber mechanism passes through the sample gas measurement part while being absorbed by ozone and reaches the intensity sensor for each long period. The mode value is calculated from the recorded data and regarded as the received light intensity. Further, the received light intensity at zero ozone is regarded as the emitted light intensity, and the ozone concentration is calculated.

  Depending on the measurement conditions, the measured values vary. Therefore, a measured value for a certain time is recorded, and a reasonable measured value (light receiving intensity) is calculated using a statistical method. From the characteristics of the measurement in the present invention, it is estimated that recorded values are collected in the mode value or in the vicinity of the mode value. Therefore, if the distribution of the recorded values is more dispersed than predicted, the occurrence of an abnormality may be suspected and an error may occur. The Lambert-Beer law is used for the ozone concentration. These calculations and analyzes are executed by a computer to control the measurement operation.

  The solid state light emitting device of the present invention is a nitride-based deep ultraviolet semiconductor device in which the radiation output intensity per solid state light emitting device can be set to 0.015 to 0.12 μw / cm 2 by power control.

The means for zero ozone in the zero set value acquisition means of the present invention includes means for sealing the inside of the measurement chamber mechanism and reducing the pressure or vacuum. Furthermore, the means for zero ozone in the zero set value acquisition means includes means for sealing the inside of the measurement chamber mechanism and filling with an inert gas. Therefore, the zero set value acquisition means of the present invention includes a generation of a zero ozone state by a solid light emitting element, a generation of a zero ozone state by vacuum, a generation of a zero ozone state by filling with an inert gas, and a reduction in ozone amount by decompression and a solid light emitting element. There are four methods of generating a zero ozone state by using ultraviolet radiation from In the method described at the end, it is preferable that the depressurization (discharge of residual gas) and ozone destruction proceed simultaneously in parallel. This is because active oxygen during ozone destruction is also discharged.

  In the present invention, the light emitting chamber mechanism, the measurement chamber mechanism, and the light receiving chamber mechanism are based on independent and detachable structures. However, as shown in FIG. 2, three mechanisms may be continuously integrated. However, since the light emitting chamber mechanism and the light receiving chamber mechanism are connected to the measurement chamber mechanism, when the measurement chamber mechanism is decompressed, vacuumed, or filled with an inert gas, all the three mechanisms are sealed, and all the three mechanisms are decompressed and vacuumed. Alternatively, an inert gas filling process is required.

  Since the present invention is provided with a mechanism for instantaneously passing the sample gas through the measurement region and the permeation time is shortened, the present invention has an effect of suppressing re-ozonization. In addition, because the sample gas path length is short and there is no gas turbulence, even if generated active oxygen or ozone that has been re-ozoned is generated, it is exhausted before measurement, and the deterioration of parts due to active oxygen is minimized. Play.

  According to the present invention, the radiant output intensity of ultraviolet rays is suppressed to a faint light of 0.015 to 0.12 (μW / cm 2), the ultraviolet rays are blinked in a short time, and the measured sample gas is not remeasured. Has the effect of being exhausted.

  According to the present invention, since ultraviolet rays having continuous wavelengths are dispersed into parallel light by a parallel lens and then narrowed down to a single wavelength by an optical filter, it is possible to eliminate further energy concentration and to maintain a long apparatus life.

It is a block diagram of the gas cross-separation type | mold ultraviolet absorption type ozone concentration measuring apparatus using the nitride-type deep ultraviolet semiconductor light emitting element which the chamber mechanism of the light emission, measurement, and light reception which implements this invention isolate | separated independently. It is a block diagram of the gas crossing type | mold ultraviolet absorption type ozone concentration measuring apparatus using the nitride-type deep ultraviolet semiconductor light-emitting device with which the chamber mechanism of light emission, measurement, and light reception which implements this invention was integrated continuously. Example 1 FIG. 5 is a graph showing the relationship between the drive current value and the radiant output intensity from an experiment using a nitride-based deep ultraviolet semiconductor light-emitting device for carrying out the present invention. FIG. 3 is a graph showing the relationship between irradiation distance and radiation output intensity from an experiment using a nitride-based deep ultraviolet semiconductor light emitting device for carrying out the present invention. FIG. 5 is a graph showing the attenuation of spectral irradiance with respect to ozone concentration from an experiment using a nitride-based deep ultraviolet semiconductor light emitting device embodying the present invention. 1 is a configuration diagram of an ozone generation / supply system for performing an experiment using a nitride-based deep ultraviolet semiconductor light-emitting element for carrying out the present invention. The graph shows the relationship between the ozone absorption cross section at a constant temperature and the ultraviolet wavelength region extracted from Non-Patent Document 2. In the ozone concentration measuring apparatus which implements this invention, it is a flowchart which sets the relative value of the light emission intensity or light reception intensity in the case of ozone zero. It is a flowchart for determining ozone concentration in the ozone concentration measuring apparatus which implements this invention.

  The ozone concentration measurement utilizes the ultraviolet absorptivity of ozone. Conventionally, mercury lamps are used for this ultraviolet light emission. Single-wavelength ultraviolet light is most preferable for measurement, and the mercury lamp vacuum discharge method emits a single wavelength, so it has become widely used. However, mercury lamps are not durable, and there are a number of problems such as the lack of a mechanism for preventing the reoccurrence of ozone in the device configuration, and a method to replace mercury lamps has been demanded. The ozone concentration measuring apparatus of the present invention is characterized in that a nitride-based deep ultraviolet semiconductor light emitting element 102 is used as an ultraviolet light emitter instead of a mercury lamp. The nitride-based deep ultraviolet semiconductor light emitting device 102 emits a continuous wavelength of 200 to 320 nm. When measuring the ozone concentration, if the sample gas moves through a long permeation distance, there is re-ozonization during permeation, and correct ozone concentration measurement cannot be performed. Therefore, in the present invention, the sample gas measuring unit 129 with a shortened sample gas path length is adopted, and a device for preventing gas turbulence, a device for removing active oxygen, and a device for preventing re-ozonization are incorporated. In addition, the weak light with a radiation output intensity of 0.015 to 0.12 (μW / cm 2) was able to promote the reduction of damage to the device due to active oxygen and the reduction of re-ozonization. In addition, measurement noise can be eliminated by blinking ultraviolet light. This is because the S / N ratio of the detection signal is increased by blinking ultraviolet rays in a short time. The nitride-based deep ultraviolet semiconductor element 102 is capable of high-speed switching and is excellent in shortening the chopping cycle. For this reason, a chopping method in which ultraviolet rays are turned on and off over time is adopted. Furthermore, if the irradiation of ultraviolet rays is interrupted during the exhaust of the gas that has been irradiated with ultraviolet rays, ultraviolet rays do not act on the same ozone molecule many times, so re-ozonization can be suppressed as much as possible. Further, in the present invention, the optical filter 130 is used which disperses the irradiation energy from the continuous wavelength to the parallel light by the parallel light lens 127 and further extracts a single wavelength from the continuous wavelength.

  FIG. 1 is a configuration diagram of a gas cross-separation type ultraviolet absorption ozone densitometer 1 using a system deep ultraviolet semiconductor light emitting device 102 embodying the present invention. The light emitting chamber mechanism 164, the measuring chamber mechanism 163, and the light receiving chamber mechanism 165 are configured, and the three mechanisms are independently separated. The light emitting chamber mechanism 164, the measurement chamber mechanism 163, and the light receiving chamber mechanism 165 are kept sealed. By removing the mounting screw part 150, maintenance work of the mechanical parts attached in the measurement chamber mechanism 163 (work for performing simple cleaning of the parts, etc.) can be performed, but after that, filling with vacuum or inert gas Thus, it is necessary to restore the sealed state. Since the light emitting chamber mechanism 164 and the light receiving chamber mechanism 165 are in a vacuum state (can be filled with an inert gas), the surface of the light emitting element protection glass 103, the parallel lens 127, the optical filter 130, the condenser lens 128, and the intensity sensor 111 is There is no formation of an oxide film due to the influence of ultraviolet rays.

  Prior to the measurement of the ozone concentration, an operation for obtaining the received light intensity (zero reference set value) that is in a zero ozone state is performed. If ultraviolet rays pass through a space where ozone does not exist, such as a vacuum or an inert gas, the ultraviolet rays do not absorb light. That is, based on the premise that there is no attenuation of ultraviolet rays, the ultraviolet rays emitted from the solid-state light emitting element reach the intensity sensor with the same intensity even when passing through the space. Therefore, the intensity received by the intensity sensor is equal to the emission intensity. However, the measuring instrument is damaged by oxidation or the like by ultraviolet rays or ozone. Further, since there is a difference in output depending on the individual solid-state light emitting elements, the relative light emission intensity (similar to the ozone zero state without light absorption) must be measured in advance when measuring the ozone concentration.

  The operation procedure for setting ozone zero will be described with reference to FIG. The flow valve 117 is closed so that the sample gas does not flow into the measurement chamber mechanism 163. Here, a case will be described in which the measurement chamber is evacuated to remove ozone. The vacuum pump 120 is actuated to open the gas measurement unit exhaust valve 119 and the chamber exhaust valve 118, and the oxygen, ozone, gas contained in the atmosphere, and minute moisture remaining in the measurement chamber mechanism 163 and the sample gas measurement unit 129 are exhausted. A vacuum is created by exhausting from the outlet 121. The ultimate suction pressure is about -85 KPa. In the future, it is considered that the zero gas can be set even in a low vacuum state and even in a state close to atmospheric pressure by proceeding with experiments. As the vacuum pump 120, a small-sized vacuum pump having a long life and maintenance-free is commercially available. Even if a vacuum gauge is not used, if the time from the internal volume of the measurement chamber mechanism 163 and the exhaust flow rate of the vacuum pump 120 to the ultimate vacuum is known in the experiment, the vacuum can be managed by time. Thereafter, for the purpose of decomposing ozone staying in the measurement chamber mechanism 163, the chopper drive power supply unit 115 of the light emitting element mounting unit 104 is operated in the continuous lighting mode to decompose ozone in the measurement chamber mechanism 163. For example, ozone decomposition becomes active by increasing the intensity of radiation output emitted from the nitride-based deep ultraviolet semiconductor light emitting device 102. However, after ozone removal, the output intensity is the same as the nitride-based deep ultraviolet semiconductor light-emitting element 102 used for ozone measurement (all in the case of multiple elements) (the intensity of each in the case of multiple elements is the same). Match) and set the zero reference. The decomposed ozone is discharged from the sample gas measuring unit 129. As the degree of decomposition of ozone proceeds, the degree of vacuum in the measurement chamber mechanism 163 increases. The weak ultraviolet light is radiated from the nitride-based deep ultraviolet semiconductor light emitting element 102 every time (the degree of vacuum is improved), and the radiation output intensity is measured. If this ozone removal is continued, the radiant output intensity becomes stable at substantially the same value. At this time, it can be determined that the zero reference has been reached when ozone has disappeared and no light is absorbed, and the zero setting is completed. Although not shown in FIGS. 1 and 2, a dedicated light emitting element for decomposing ozone can be attached to the measurement chamber mechanism 163 (for example, attached to the side surface of the measurement chamber mechanism 163). The ozone decomposition reaction not only in the sample gas measurement unit 129 but also in the entire measurement chamber mechanism 163 becomes active, and a state without ozone can be created with higher accuracy. However, after removing ozone, it is necessary to obtain the zero reference value again with only the element for measuring the concentration.

  In order to determine whether the ozone zero reference value has been reached, in addition to the method of operating the vacuum pump for a sufficient period of time, ozone removal by the vacuum pump and ozone decomposition by ultraviolet rays are continuously performed. There is a method. The present invention employs the latter. That is, light is irradiated by chopping with the nitride-based deep ultraviolet semiconductor light emitting element 102 of the light chamber mechanism 164 turned on and off. The light travels in the irradiation direction 126 and the parallel lens 127 attached to the parallel lens unit 106 is irradiated with ultraviolet light having a continuous wavelength. The parallel lens 127 turns the parallel ultraviolet light into the optical filter 130 attached to the optical filter unit 140. The continuous wavelength is reduced to a single wavelength by the optical filter 130, passes through the transmission filter 162 attached to the transmission filter unit 161, and enters the sample gas measurement unit 129 in the measurement chamber mechanism 163. If ozone is present, ultraviolet light decomposes ozone, and the radiant output intensity attenuates. In the absence of vacuum or ozone, ultraviolet rays are not absorbed by ozone, and the radiation output intensity (luminescence intensity) is not attenuated. Light having a single wavelength that has passed through the sample gas measurement unit 129 passes through the transmission filter 162 attached to the transmission filter unit 161 and is converged by the condenser lens 128 attached to the condenser lens unit 110 in the light receiving chamber mechanism 165. And arrives at the intensity sensor 111. The value measured by the intensity sensor 111 attached to the light receiving chamber mechanism 165 is output as a voltage value. The voltage value is input to the microcomputer 124 through the amplifier 112 and the interface 123. In the state of ozone zero, I = the radiation output intensity of incident light is the ozone zero reference value, and the ozone zero reference setting is completed. The radiation output intensity at this time can be regarded as the emission intensity.

  After setting the ozone zero reference value, measure the concentration of the sample gas. Here also, description will be given based on FIG. In a state where the vacuum pump 120 is operated, the chamber exhaust valve 118 is closed and the gas measuring unit exhaust valve 119 is opened. The flow rate valve 117 is opened, the gas flow rate is set to a predetermined value by the flow meter 116, and the sample gas is caused to flow from the sample gas inlet 122 into the sample gas measuring unit 129. The sample gas passes through the short sample gas path length between the gas injection 109 and the gas discharge 108 in the sample gas measurement unit 129 of the measurement chamber mechanism 163 without any disturbance. Since the pressure difference is utilized, the sample gas flows from the sample gas injection 109 to the gas discharge 108 in the direction 107 of the sample gas. With the sample gas flowing into the sample gas measuring unit 129, the chopper drive power supply unit 115 of the light emitting device mounting unit 104 is operated to turn on and off the nitride-based deep ultraviolet semiconductor light emitting device 102, and radiate continuous wavelength ultraviolet rays. The radiation output intensity of 200 to 320 emitted from the nitride-based deep ultraviolet semiconductor light emitting device 102 is weak light of 0.015 to 0.12 (μW / cm 2). The parallel lens 127 converts the ultraviolet light into parallel light, and the optical filter 130 extracts the ultraviolet light having a predetermined single wavelength. Ultraviolet light having a single wavelength is passed through the sample gas measuring unit 129 and is transmitted while decomposing ozone contained in the sample gas. At this time, ultraviolet rays are attenuated. Ultraviolet light having a single wavelength and parallel light is converged by the condenser lens 128 and received by the intensity sensor 111. The value measured by the intensity sensor 111 is output as a voltage value. The radiated output intensity of the transmitted light is O (received light intensity), and the voltage value is input to the microcomputer 124 through the amplifier 112 and the interface 123.

  When incident light output intensity (zero ozone reference value) I (light emission intensity) and transmitted light output intensity O (received light intensity) are input to the microcomputer 124, the microcomputer 124 represents Lambert-Beer's law. The ozone concentration is calculated by calculating from Equation 1 given above. The microcomputer 124 calculates the mode value by a statistical method and displays it on the display 125.

  Furthermore, in the present invention, in order to obtain a zero reference set value or light emission intensity at zero ozone, a method of extinguishing ozone by sufficiently irradiating a sealed measurement space with ultraviolet rays is proposed. When this method is adopted, control by a computer becomes particularly important. 8 and 9 explain the operation of the present invention with a focus on computer control.

  FIG. 8 is a process flowchart in which the intensity of ultraviolet rays received by the intensity sensor in an environment where ozone is not present is regarded as the emission intensity. If the exhaust gas outlet 121 and the sample gas inlet 122 are closed and disconnected from the outside, and the gas from the measurement chamber mechanism 163 is discharged by the vacuum pump 120, a vacuum state can be obtained. If the vacuum state is set in advance, there is an advantage that the zero set value can be acquired quickly, and the residue is also removed, and the measurement environment is improved. However, in this embodiment, in order to clarify the characteristics of the present invention, the zero set value acquisition means is a method of revealing a zero ozone state only by irradiating the sealed measurement chamber mechanism 163 with ultraviolet rays. Adopted. Although not shown, it can be said that it is preferable in actual operation to operate the vacuum pump for the purpose of removing the residue in the measurement chamber in parallel with the zero setting means.

  Hereinafter, the means will be described. First, in step S <b> 801, measurement operation information is extracted from a storage device attached to the microcomputer 124. In the measurement operation information, ultraviolet irradiation time necessary for ozone extinction, light emission power for each nitride-based deep ultraviolet semiconductor light emitting element 102, and the like are recorded. The irradiation time and light emission intensity that are the most efficient and reduce the damage to the device are selected, and the execution is started. In S802, the work storage area used when executing this processing is cleared. The work storage area includes an ultraviolet irradiation time counter per time, prerecorded data of intensity sensor values, a comparison counter when the sensor values are the same.

  In order to close the sample gas inlet 122 and the exhaust gas outlet 121 in the opening portion of the measurement chamber mechanism 163 and to make it sealed, the vacuum pump 120 is instructed to close (S803). In response to a command from the microcomputer 124, all the bubbles are closed (S804). Next, based on the measurement operation information, the designated nitride-based deep ultraviolet semiconductor light emitting element 102 (S805) and the intensity of its output are designated (S806). Although not shown, a nitride-based deep ultraviolet semiconductor light emitting device 102, which is one of solid state light emitting devices, is used in the present embodiment, but this is not limited to one. Similarly, although not shown, the solid state light emitting device may include an ultraviolet light emitting device different from the nitride-based deep ultraviolet semiconductor light emitting device.

  The microcomputer 124 instructs the light emitting chamber mechanism 164 to continuously irradiate ultraviolet rays for a specified time (S807). As a result of this command, the specified nitride-based deep ultraviolet semiconductor light emitting element 102 (s) emits ultraviolet light at the specified output intensity for the specified time (S808). The microcomputer 124 receives the value of the received light intensity from the intensity sensor 111 after a specified time (S809). The intensity sensor 111 notifies the intensity (S810).

  In step S811, the microcomputer 124 compares the received light intensity value recorded previously with it, and if it is the same or within the error range, predicts that ozone is zero (no light absorption). Otherwise, the work data zero value measurement counter is cleared (S812). This is because the previous ozone zero state is regarded as a coincidence and the initial state is restored in order to pursue the ozone zero state again. The zero value measurement counter is provided based on the idea that it can be determined that ozone is zero if the state where ozone is expected to be zero continues for a specified number of times. Since zero ozone (no light absorption) is predicted in S811, this zero value measurement counter is updated once (S813). When this count reaches the designated number, it may be determined that ozone is zero (S814). Otherwise, the same state continues again, and the recording of UV irradiation and received light intensity is continued until the specified number of times is reached.

  If it is determined that ozone is zero, the microcomputer 124 stops the ultraviolet irradiation (S815, S816). The same value continuously recorded by the intensity sensor 111 at this time is the zero set value. This is recorded in a non-volatile storage area (S817). In addition, analysis data that determines the measurement time, emission intensity, and solid-state light emitting element to be used is the best specified value analysis information that is most efficient for obtaining zero set values and calculating ozone concentration and maintaining the stability of the equipment. The data is recorded in a storage device attached to the microcomputer 124 (S818).

  FIG. 9 is a flowchart of processing for calculating the ozone concentration based on the measured received light intensity under the ozone environment, assuming that the zero setting value is the relative light emission intensity. The solid light emitting elements used in the ozone zero set value acquisition means and the power intensity at the time of ultraviolet light emission are the same, and the information is attached to the microcomputer 124 including the previously recorded relative light emission intensity (zero set value). Supplied from the storage device.

  Hereinafter, FIG. 9 will be described. Measurement operation information in which the above-mentioned relative light emission intensity and the intermittent short period and intermittent long period of ultraviolet light emission to be described later are recorded is taken out from the storage device attached to the microcomputer 124 (S901). Next, in S902, the work storage area used when executing this processing is cleared. In response to a command from the microcomputer 124, the vacuum pump 120 is arranged so that an external sample gas is blown out from the sample gas injection unit 109 of the sample gas measurement unit 129 in the measurement chamber mechanism 163, sucked into the gas discharge unit 108 and then out It operates at the specified pressure and adjusts various valves (S903, S904).

  Under the control of the microcomputer 124, the designated solid state light emitting element of the light emitting chamber mechanism 164 starts blinking with the designated period (S905, S906). The designated solid-state light-emitting element is a solid-state light-emitting element (or a plurality of solid-state light-emitting elements) that have been subjected to ozone erasure by the zero set value acquisition means. The intensity of ultraviolet rays is the intensity used when ozone is erased. In the present invention, when the ozone concentration measurement is performed, intermittent irradiation that repeats blinking is employed without continuously irradiating ultraviolet rays. This blinking has a short cycle and a long cycle. In the short period, the S / N ratio is increased and the measurement noise can be removed by blinking the ultraviolet rays with a very short period. The long period is a period that includes a short period of time in which the ozone that has been irradiated once is not re-ozonated, and the ozone is not irradiated with ultraviolet light and exits from the exhaust gas outlet 121 to the outside. That is, short cycle + re-ozone exhaust time (no irradiation). Although ozone is destroyed by a series of short-period light emission, there is re-ozonization due to the active oxygen produced at the same time, and if this ozone is again exposed to ultraviolet rays, an unexpected value is added to the ozone concentration. A mechanism was provided so that sample gas containing ozonized ozone was sucked and exhausted to the outside.

  In step S907, the number of long periods is extracted from the measurement operation information (S908) and measurement is started in order to execute long-period ultraviolet irradiation interruption. In S909, the timing of irradiation time and non-irradiation time is executed by computer control so as to blink ultraviolet rays in a short cycle.

  In S910, the microcomputer 124 instructs the light emission chamber mechanism 164 about the ultraviolet irradiation time, power, and the like to emit ultraviolet light (S911). The light receiving chamber mechanism 165 reports the intensity value of the ultraviolet ray received by the intensity sensor 111 to the microcomputer 124 (S912). By flashing, this repetition is for a short period. These are recorded in a storage device attached to the microcomputer 124. For these records, the microcomputer 124 selects values that are regarded as appropriate measurement values (S913). This measurement and processing are executed for a period (S914).

  In S915, after the short period of ultraviolet blinking, in order to prevent the re-ozone re-measurement described above, the irradiation of ultraviolet rays is stopped in anticipation of the time during which the sample gas is sucked into the exhaust gas outlet. The microcomputer 124 instructs the light emission chamber mechanism 164 to stop the ultraviolet light emission for a specified time (S916). This long-period intermittent UV irradiation is executed for the designated number of times, and when the number of times is reached (S917), the operation of the ozone concentration measurement device is stopped (S918). The light emission chamber mechanism 164 is instructed to stop ultraviolet irradiation (S919), and the measurement chamber mechanism 163 is instructed to stop the sample gas flowing through the sample gas measuring unit 129 (S920).

  The mode value is obtained from the data of intensity sensor values for the number of long cycles by a statistical method. In this case, since an appropriate pattern of the dispersion distribution exists, the recording deviated therefrom is removed, and the received light intensity is determined from the data near the mode value (S921). Although not shown, if the distribution state is abnormal, a device failure or an operation error is suspected, resulting in a measurement error. Here, the ozone zero set value is regarded as the emission intensity, and the ozone concentration is calculated using the Lambert-Beer formula (S922).

  FIG. 2 shows a gas cross type ultraviolet absorption ozone concentration meter 2 in which a nitride-based deep ultraviolet semiconductor light emitting element 102 is used in a vacuum chamber mechanism 101 and a gas discharge 108 and a gas injection 109 are attached in a sample gas measurement unit 129. It is a block diagram. An outline of the configuration diagram will be described with reference to FIG. The light emitting element attachment portion 104 and the cover 160 are attached and sealed with attachment screw portions 150. A feature is that maintenance work and part replacement work of all mechanical parts in the vacuum chamber 101 can be performed by removing the cover 160 attached to the mounting screw part 150.

  After setting the ozone zero reference value, measure the sample gas. The gas pump exhaust valve 119 is opened and the chamber exhaust valve 118 is closed so that the sample pump does not flow into the vacuum chamber mechanism 101 by operating the vacuum pump 120. With the sample gas flowing into the sample gas measuring unit 129, the chopper drive power supply unit 115 of the light emitting device mounting unit 104 is operated to turn on and off the nitride-based deep ultraviolet semiconductor light emitting device 102, and radiate continuous wavelength ultraviolet rays. The ultraviolet rays are attenuated by being absorbed into ozone that is introduced into the sample gas measuring unit 129 and contained in the sample gas. The ultraviolet light having a single wavelength dispersed in parallel is converged by the condenser lens 128, received by the intensity sensor 111, and used as the radiation output intensity of the transmitted light. The value measured by the intensity sensor 111 is output as a voltage value. The radiated output intensity of the transmitted light is O, and the voltage value is input to the microcomputer 124 through the amplifier 112 and the interface 123.

The purpose of the experiments in FIGS. 3 to 6 is that the nitride-based deep ultraviolet semiconductor light-emitting device 102 produced by a manufacturing method described in Patent Document 4 is actually used and has the effect of re-ozonization with active oxygen. The lower limit value and the upper limit value of the radiant output intensity of 260 nm ultraviolet light are found, and whether the weak light of the lower limit value can be measured is found using the ozone generation / supply system 6. In addition, an experiment was conducted to confirm the necessity of means using the parallel lens 127 and the sample gas measurement unit 129 used in the present invention.

  (Explanation of Experimental Apparatus) FIG. 6 is a block diagram of an ozone generation / supply system 6 for conducting an experiment using the nitride-based deep ultraviolet semiconductor light emitting device 102 for carrying out the present invention. In order to find the lower limit of faint light, the ozone generation / supply system 6 was used. Atmospheric gas is injected into the ozone generator 201 by the pump 203 and the ozone concentration set by the densitometer 202 is generated. The generated ozone gas enters the ozone measuring cell 206 and emits ultraviolet light from the nitride-based deep ultraviolet semiconductor light emitting device 102 set in the light source unit 209. Ultraviolet rays are absorbed and attenuated by the ozone concentration gas while passing through the ozone measuring cell 206. The ozone gas that has passed through the ozone measuring cell 206 is processed by the ozone decomposer 205 and discharged into the atmosphere. The length of the ozone measuring cell 206 is 30 cm. A temperature / pressure gauge 204 is attached to the ozone measuring cell 206. Ultraviolet radiation output intensity was measured with a spectroscope at the Tokyo Metropolitan Industrial Technology Research Center. (Specifications Prism grating method Measurement wavelength 200 nm to 2500 nm, manufactured by Spectrometer Co., Ltd. Model No. US-25ART) The radiant output intensity without ozone and the radiant output intensity with ozone are measured by the spectrometer 207. The radiation output intensity of incident light (ozone zero reference value) measured by the spectroscope 207 is I, and the radiation output intensity of transmitted light (ozone setting value) is O. The pressure, temperature, and atmospheric temperature in the ozone measurement cell 206 were measured as reference values. The ozone concentration is calculated by calculating from Lambert-Beer's law, Equation 1. A more accurate ozone generation concentration can be found from the ozone concentration generated by the ozone generator 201 and the ozone concentration calculated from the actual measurement value. Although not shown in FIG. 6, a flow rate adjusting valve is attached to the ozone generator 201. Further, a nitride-based deep ultraviolet semiconductor light emitting element 102 set in the light source unit 209 is included.

(Experiment 1) FIG. 5 shows an ozone concentration generated from an experiment using the ozone generation / supply system 6 by radiating a wavelength of 250 to 260 nm using the nitride-based deep ultraviolet semiconductor light emitting device 102 embodying the present invention. This is a graph showing the radiation output intensity when ultraviolet rays are attenuated. The purpose is to check whether the output intensity of a slight ultraviolet ray can be measured by the spectroscope 207. For example, when ozone of 200 ppb is generated, the vertical axis represents the spectral irradiance (radiant output intensity) value, and the horizontal axis represents the wavelength value emitted from the nitride-based deep ultraviolet semiconductor light emitting device 102. The spectral irradiance (radiant output intensity) (501) without ozone and the spectral irradiance (radiant output intensity) (502) when the ozone concentration is 200 ppb can be seen from the graph. From the experiment, the lower limit value of the wavelength of 250 to 260 nm at which re-ozonization by active oxygen is suppressed and radiation output intensity can be measured stably and accurately was set to 0.015 (μW / cm ² ).

(Experiment 2) FIG. 3 shows a driving current value and radiation output from an experiment using the ozone generation / supply system 6 that emits a wavelength of 250 to 260 nm using the nitride-based deep ultraviolet semiconductor light emitting device 102 embodying the present invention. This is a graph showing the relationship of strength.
Using the ozone generation / supply system 6, for example, the radiation output intensity and the drive current value when the ozone concentration is 0 ppm are graphed. The vertical axis represents the value of the radiation output intensity, and the horizontal axis represents the wavelength emitted from the nitride-based deep ultraviolet semiconductor light emitting device 102. The drive current value at which a radiation output intensity of about 0.015 (μW / cm ² · 255 nm) is emitted at a wavelength of 250 to 260 nm is 5 mA (306). The radiation output intensity can be read with respect to the drive current value of 30 mA (301), the drive current value of 25 mA (302), the drive current value of 20 mA (303), the drive current value of 15 mA (304), and the drive current value of 10 mA (305). The driving current value of the wavelength of 250 to 260 nm that can suppress the re-ozonization by the active oxygen from the experiment and can measure the radiation output intensity stably and accurately is 30 mA (301), and the upper limit value is 0.12 (μW / cm ² ). It was. Furthermore, by proceeding with the experiment, it is considered that a value that can be stably and accurately measured can be found with a radiation output intensity of 0.12 μW / cm ² or more while suppressing the influence of re-ozonization by active oxygen.

(Experiment 3) FIG. 4 is a graph showing the relationship between the transmission distance and the radiation output intensity by emitting a wavelength of 250 to 260 nm using the nitride-based deep ultraviolet semiconductor light emitting device 102 for carrying out the present invention. Do not use the ozone measurement cell 206 of the ozone generation / supply system 6 in order to test that the sample gas passing through the measurement cell is irradiated with ultraviolet rays many times during transmission while the sample gas moves through a long transmission distance. Measurement was performed in the medium (ozone concentration of 10 ppb or less). The change of the radiation output intensity was experimented by changing the transmission distance. The vertical axis represents the radiation output intensity value, and the horizontal axis represents the wavelength value emitted from the nitride-based deep ultraviolet semiconductor light emitting device 102. Radiation output intensity of 0.12 μW / cm ² is emitted from the nitride-based deep ultraviolet semiconductor light emitting device 102, and the value of the radiation output intensity with respect to a transmission distance of 10 cm (401), a transmission distance of 20 cm (402), and a transmission distance of 30 cm (403) Can be read. Measurement without using the ozone measuring cell 206 is dispersed in the atmosphere before the ultraviolet rays reach the spectroscope 207, and the radiant energy is attenuated. In the measurement using the measurement cell from the experiment, ozone is irradiated many times during transmission while the dispersed ultraviolet rays are reflected by the measurement cell and the sample gas moves through a long transmission distance.

  The mechanism of the ozone concentration measurement of the present invention targets the gas phase. However, this mechanism is also effective for the liquid phase. For the concentration measurement, it is necessary to obtain a value of relative received light intensity in a zero ozone state in advance. In other words, the most important means for characterizing the present invention is how to show the state in which ozone is not present in the measurement environment. This means can be filled with a substance inert to vacuum or ultraviolet rays. However, conditions differ between the gas phase and the liquid phase, and the same mechanism cannot be applied simply. This is because there are time-consuming processes such as removal or replacement of the medium. In this regard, in the present invention, it has been found that the residual ozone can be destroyed and the state of zero ozone can be set by irradiation with ultraviolet rays. There are many items to be considered, such as how to deal with the destruction of ozone and how much the output of the solid state light emitting device used in the gas phase should be adjusted in the liquid phase. However, for the reasons described above, the present invention is considered to have characteristics that can be applied to the liquid phase.

  Specifically, when acquiring the liquid phase zero set value, the valve is closed to confine the liquid phase to be measured in order to eliminate the entry and discharge of the liquid phase. By continuously irradiating ultraviolet rays from all solid-state light emitting elements used for measurement, ozone contained in the liquid phase confined in the measurement unit is destroyed. In a state where all the ozone contained in the liquid phase has been destroyed, the received light intensity received by the intensity sensor does not change. Therefore, the received light intensity of the transmitted ultraviolet light is measured at least twice, and the intensity sensor value when the intensity sensor value stops changing is set as the received light intensity at zero liquid phase ozone.

DESCRIPTION OF SYMBOLS 1 Gas cross-separation type ultraviolet absorption ozone concentration meter 2 Gas cross-type ultraviolet absorption ozone concentration meter 6 Ozone generation and supply system 101 Vacuum chamber mechanism 102 Nitride-based deep ultraviolet semiconductor light emitting element 103 Light emitting element protection glass 104 Light emitting element mounting portion 105 Light emitting element adapter 106 Parallel lens unit 107 Sample gas direction 108 Gas discharge unit 109 Gas injection unit 110 Condensing lens unit 111 Intensity sensor 112 Amplifier 115 Chopper drive power supply unit 116 Flow meter 117 Flow valve 118 Chamber exhaust valve 119 Gas measurement unit exhaust Valve 120 Vacuum pump 121 Exhaust gas outlet 122 Sample gas inlet 123 Interface 124 Microcomputer 125 Display 126 Irradiation direction 127 Parallel lens 128 Condensing lens 129 Sample gas measurement unit 130 Optical filter 14 Optical filter section 150 Mounting screw section 160 Cover 161 Transmission filter section 162 Transmission filter 163 Measurement chamber mechanism 164 Light emission chamber mechanism 165 Light reception chamber mechanism 201 Ozone generator 202 Density meter 203 Pump 204 Temperature / pressure gauge 205 Ozone decomposer 206 For ozone measurement Cell 207 Spectrometer 208 Light 209 that has passed through ozone 209 Light source

Claims (9)

  A light emitting chamber mechanism provided with at least one solid-state light emitting element that emits ultraviolet rays including a wavelength region of 200 nm to 320 nm, a gas injection unit that blows out a sample gas across the sample gas measurement unit, and a gas discharge unit that sucks the sample gas Are provided at at least one pair at opposite positions, and ultraviolet rays from the light emission chamber mechanism are transmitted in a direction perpendicular to the flow of the sample gas in the sample gas measuring unit from the gas injection unit to the gas discharge unit. A measurement chamber mechanism having a structure and a light receiving chamber mechanism having an intensity sensor that receives ultraviolet light emitted from the measurement chamber mechanism and measures the received light intensity are constituted by the three mechanisms that can be removed, and have no ozone. The ultraviolet light transmitted through the measurement chamber mechanism in the state is received by the intensity sensor, and the zero value is set so that the received light intensity value is the ozone zero value. The ozone concentration is calculated by the value acquisition means and the light receiving value of the intensity sensor when the ultraviolet light is transmitted and the ozone zero value regarded as the light emission intensity in the sample gas measuring unit in a state where the sample gas flows. An ozone concentration measuring device having an ozone concentration calculating means.   The light emitting chamber mechanism is hermetically sealed in a vacuum or filled with an inert gas, and the solid light emitting element in the mechanism intermittently emits ultraviolet light by controlling the chopper drive power supply, and the ultraviolet light passes through the parallel lens. 2. The ozone concentration measuring apparatus according to claim 1, wherein the ozone concentration measuring device is converted into parallel light and reaches an optical filter, and ultraviolet light having a specified single wavelength passes through the optical filter and enters the measurement chamber mechanism.   The intermittent period of the ultraviolet light emission of the chopper drive power supply unit is between the first short period and the second short period between the short period in which ozone measurement is performed by blinking ultraviolet light, and the first short period. Estimating the time for which the sample gas irradiated with ultraviolet rays is sucked into the gas discharge portion in the above, an expected gas discharge time for interrupting the ultraviolet irradiation is provided, and an interval that combines the first short period and the expected gas discharge time The ozone concentration measuring apparatus according to claim 1, wherein the two periods are executed by computer control.   The light receiving chamber mechanism is hermetically sealed in a vacuum or incapable gas filled state, and the ultraviolet light emitted from the measuring chamber mechanism is focused by a condensing lens provided in the mechanism and irradiated to the intensity sensor. The ozone concentration measuring apparatus according to any one of claims 1 to 3.   The zero set value acquisition means temporarily seals the inside of the measurement chamber mechanism to block the intrusion of external air, and continuously irradiates ultraviolet rays from all the solid state light emitting elements used for the measurement, so that the inside of the measurement chamber mechanism In the process of destroying ozone, the received light intensity of transmitted ultraviolet rays is measured at least twice, and the value of the intensity sensor when the value of the intensity sensor stops changing is the received light intensity at zero ozone. The ozone concentration measuring apparatus according to any one of claims 1 to 4.   The ozone concentration calculation means records the measurement value when the ultraviolet light incident on the measurement chamber mechanism passes through the sample gas measurement unit while being absorbed by ozone and reaches the intensity sensor for each long period, The ozone concentration measuring apparatus according to any one of claims 1 to 5, wherein the ozone concentration is calculated by calculating the mode value from the recorded data and regarding the received light intensity, regarding the received light intensity at zero ozone as the emitted light intensity.   2. The solid-state light emitting device is a nitride-based deep ultraviolet semiconductor device capable of setting a radiation output intensity per solid light-emitting device to 0.015 to 0.12 μw / cm 2 by power control. The ozone concentration measuring apparatus according to any one of items 1 to 6.   The ozone concentration measuring apparatus according to any one of claims 1 to 7, wherein means for zeroing ozone in the zero set value obtaining means includes means for sealing the inside of the measurement chamber mechanism and reducing the pressure or vacuum.   The ozone concentration measuring apparatus according to any one of claims 1 to 7, wherein means for zeroing ozone in the zero set value obtaining means includes means for sealing the inside of the measurement chamber mechanism and filling with an inert gas.