Device and method for gas concentration measurement

Abstract

To provide a device and a method for gas concentration measurement.SOLUTION: A gas concentration measuring device and a method thereof include a gas detection chamber, a temperature sensing element, a pressure sensing element, a light source supply device, and a photodetector to measure the concentration of a measurement object gas (for example, ozone). The temperature sensing element measures the temperature of the measurement object gas, and the pressure sensing element measures the pressure of the measurement object gas. The light source supply device adopts a UV-LED as an ultraviolet light source, supplies a first detection beam and a correction beam having different ozone absorption, and splits the spectrum into a spectrum passing through the measurement object gas and a spectrum not passing through the measurement object gas by a spectral element. The photodetector measures the light intensity of the first detection beam and the correction beam when the measurement object gas comprises ozone and the light intensity of the first detection beam and the correction beam when the measurement object gas does not comprise ozone, respectively. When the light intensities are compared, the concentration of ozone gas can be calculated according to the Beer-Lambert law.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a measuring device and a method thereof, and more particularly to a gas concentration measuring device and a method thereof. [Background technology]

[0002] With the development of industry, various kinds of gases are used in various industries and living environments. For example, ozone is often used in sterilization equipment and semiconductor wafer manufacturing, but the commercially available devices for measuring ozone concentration can no longer meet the requirements of accurate, stable and fast feedback of ozone concentration. Current ozone concentration measuring instruments adopt the ultraviolet absorption method, in which ultraviolet light from an ultraviolet light source passes through ozone in a quartz glass tube, and the optical sensing signal is measured by a photodetector, and then the concentration of ozone is calculated according to the Beer-Lambert Equation.

[0003] However, existing ozone concentration measuring instruments mainly use low-pressure mercury lamps as an ultraviolet light source. Although low-pressure mercury lamps can provide an ultraviolet light source with an absorption spectrum close to that of ozone, low-pressure mercury lamp technology has the following long-standing drawbacks that have been difficult to overcome: (1) The warm-up time is long, and it takes a long time before you can measure again. (2) The measurement requires a high-voltage power supply, which consumes energy. (3) The ultraviolet light source scatters around, reducing utilization rate. (4) Due to its large size, only one fixed wavelength light source can be installed in one device, and the device needs to be replaced when the ozone concentration range is too different. (5) Relatively short life span. (6) Mercury vapor is generated.

[0004] In addition, when the quartz glass tube wall becomes dirty or has deposits, an error may occur in the light sensing signal measured by the light detector. However, the existing ozone concentration measuring device cannot provide feedback or correct the error in real time. This shows that the existing ozone concentration measuring device obviously does not meet the requirements for accurate, stable and fast feedback of the ozone concentration. Summary of the Invention [Problem to be solved by the invention]

[0005] The main object of the present invention is to provide a gas concentration measuring apparatus and method capable of solving the problems encountered when measuring the concentration of ozone gas using conventional techniques, namely, when a low-pressure mercury lamp is used as an ultraviolet light source, the warm-up time is too long, the starting voltage is too high, and the light source usage rate is too low, and when a single wavelength is used in the conventional techniques, the range of detectable concentrations is too small. [Means for solving the problem]

[0006] The gas concentration measurement device of the present invention is a gas concentration measurement device for measuring the gas concentration of a gas to be measured, the gas concentration measurement device comprising: a gas detection chamber having a gas to be measured, one of the chambers being connected to a gas inlet / outlet passage, a temperature sensing element for detecting the gas temperature of the gas to be measured, a pressure sensing element for detecting the gas pressure of the gas to be measured, at least one light source provided on a first side of the gas detection chamber for generating a first detection beam and a correction beam, the gas to be measured being a gas having a higher absorbance than the first detection beam, and a light source for dividing the first detection beam into a first detection spectrum and a second detection spectrum and for dividing the correction beam into a first correction spectrum and a second correction spectrum, the first detection spectrum and the first correction spectrum pass through the gas detection chamber and the gas to be measured in the gas detection chamber, and the second detection spectrum and the second correction spectrum pass through the gas detection chamber and the gas detection chamber, and an optical detection device having at least a first optical sensing element and a second optical sensing element located on the second side and the first side of the gas detection chamber, respectively, which calculates a first detected concentration of the target gas by measuring the light intensity of the first detection light beam and the light intensity of the second detection light beam, respectively, and calculates a corrected concentration of the target gas by measuring the light intensity of the first correction light beam and the light intensity of the second correction light beam, respectively, and obtains the gas concentration of the target gas after subtracting the corrected concentration from the first detected concentration.

[0007] In the gas concentration measuring device of the present invention, both ends of the gas inlet / outlet passage are a passage gas inlet and a passage gas outlet, respectively, the passage gas inlet is an inlet for the gas to be measured, and the passage gas outlet is an outlet for the gas to be measured, the gas detection chamber is a hollow chamber body having the chamber, both ends of the hollow chamber body have a detection gas inlet and a detection gas outlet, respectively, the detection gas inlet and the detection gas outlet are connected to the chamber of the hollow chamber body, and the measurement gas flows continuously through the chamber of the hollow chamber body of the gas detection chamber.

[0008] The gas concentration measurement device according to the present invention further includes a processing element, which calculates the first detected concentration of the target gas based on the temperature of the target gas, the pressure of the target gas, the light intensity of the first detection spectrum, the light intensity of the second detection spectrum, the optical path length of the target gas in the gas detection chamber, and the absorption coefficient of the target gas, and the processing element further calculates the corrected concentration of the target gas based on the temperature of the target gas, the pressure of the target gas, the light intensity of the first correction spectrum, the light intensity of the second correction spectrum, the optical path length of the target gas in the gas detection chamber, and the absorption coefficient of the target gas.

[0009] In the gas concentration measurement device according to the present invention, the measurement target gas is ozone, and the first detection beam and the correction beam from the light source are ultraviolet rays.

[0010] In the gas concentration measurement device of the present invention, the spectroscopic element is an inclined beam splitter, and the spectroscopic element causes the first detection spectrum and the first correction spectrum to have the same first optical path, and the second detection spectrum and the second correction spectrum to have the same second optical path.

[0011] In the gas concentration measuring device according to the present invention, the gas detection chamber is a quartz glass tube.

[0012] In the gas concentration measurement device of the present invention, the wavelength of the first detection beam is within the absorption wavelength range of the target gas, and the wavelength of the correction beam is outside the absorption wavelength range of the target gas, thereby correcting light absorption interference errors caused by the gas detection chamber.

[0013] In the gas concentration measurement device of the present invention, the light source supply device further includes a light source control element for controlling the light source of the light source supply device to provide the first detection beam and the correction beam in an alternating light mode.

[0014] In the gas concentration measurement apparatus of the present invention, the alternating light mode is on and off in a pulsed or interval format to provide the first detection beam and the correction beam.

[0015] In the gas concentration measuring device of the present invention, when the gas concentration of the gas to be measured obtained by subtracting the correction concentration from the first detected concentration is lower than a default value, the light source supplies at least one second detection beam instead of the first detection beam, and the wavelength and / or brightness of the second detection beam is different from the wavelength and / or brightness of the first detection beam.

[0016] In the gas concentration measurement device according to the present invention, the light source has one or more light emitting elements, thereby supplying the first detection beam and the correction beam.

[0017] A gas concentration measurement method of the present invention is a gas concentration measurement method for measuring the gas concentration of a measurement target gas, the method comprising the steps of preparing a gas detection chamber, communicating the gas detection chamber with a gas inlet / outlet passage so that a measurement target gas is present in the gas detection chamber, a temperature measurement step of detecting a gas temperature of the measurement target gas, a pressure measurement step of detecting a gas pressure of the measurement target gas, preparing a first detection beam and a correction beam, and measuring an absorbance of the measurement target gas for the first detection beam greater than an absorbance of the measurement target gas for the correction beam, and dividing the first detection beam into a first detection beam that passes through the measurement target gas in the gas detection chamber and a second detection beam that does not pass through the measurement target gas in the gas detection chamber. the gas concentration of the target gas is obtained by measuring the light intensity of the first detection beam and the light intensity of the second detection beam, and then calculating a first detected concentration of the target gas by measuring the light intensity of the first detection beam and the light intensity of the second detection beam, respectively; and a correction step of calculating a corrected concentration of the target gas by measuring the light intensity of the first correction beam and the light intensity of the second correction beam, respectively, and subtracting the corrected concentration from the first detected concentration to obtain the gas concentration of the target gas.

[0018] In the gas concentration measurement method according to the present invention, the measurement target gas flows continuously through the gas detection chamber.

[0019] In the gas concentration measurement method according to the present invention, the light intensity measurement step further includes calculating the first detected concentration of the target gas from the temperature of the target gas, the pressure of the target gas, the light intensity of the first detection spectrum, the light intensity of the second detection spectrum, the optical path length of the target gas in the gas detection chamber, and an absorption coefficient of the target gas, and the correction step further includes calculating the corrected concentration of the target gas from the temperature of the target gas, the pressure of the target gas, the light intensity of the first correction spectrum, the light intensity of the second correction spectrum, the optical path length of the target gas in the gas detection chamber, and the absorption coefficient of the target gas.

[0020] In the gas concentration measuring method according to the present invention, the measurement target gas is ozone, and the first detection beam and the correction beam are ultraviolet rays.

[0021] In the gas concentration measurement method of the present invention, the spectroscopic step is performed by a spectroscopic element, whereby the first detection spectrum and the first correction spectrum have the same first optical path, and the second detection spectrum and the second correction spectrum have the same second optical path.

[0022] In the gas concentration measuring method according to the present invention, the gas detection chamber is a quartz glass tube.

[0023] In the gas concentration measurement method according to the present invention, the wavelength of the first detection beam is within the absorption wavelength range of the target gas, and the wavelength of the correction beam is outside the absorption wavelength range of the target gas, thereby correcting light absorption interference errors due to the material of the gas detection chamber.

[0024] The gas concentration measurement method according to the present invention further includes controlling a light source using a light source control element to provide the first detection beam and the correction beam in an alternating light mode.

[0025] In the gas concentration measurement method according to the present invention, the alternating light mode is on and off in a pulsed or interval fashion to provide the first detection beam and the correction beam.

[0026] The gas concentration measurement method of the present invention provides, when the gas concentration of the gas to be measured obtained by subtracting the correction concentration from the first detection concentration is lower than a default value, at least one second detection beam is supplied instead of the first detection beam, and the wavelength and / or brightness of the second detection beam is different from the wavelength and / or brightness of the first detection beam.

[0027] The gas concentration measurement method according to the present invention further includes providing the first detection beam and the correction beam by a light source having one or more light emitting elements. Effect of the Invention

[0028] The gas concentration measuring device and method according to the present invention have the following advantages. (1) Compared with the conventional technology that uses a low-pressure mercury lamp as an ultraviolet light source, the gas concentration measuring device of the present invention uses a smaller-sized light-emitting diode as an ultraviolet light source, and therefore can accommodate ozone gas having a different concentration range, eliminating the need to replace equipment.

[0029] (2) Using a light-emitting diode as an ultraviolet light source, no warm-up time is required when starting up the equipment. By turning it on and off in a pulsed manner, an ultraviolet light source can be provided, allowing for instant correction.

[0030] (3) By using a light-emitting diode as the ultraviolet light source, the concentration of the continuously flowing target gas can be measured instantly, accurately and quickly. It does not require warm-up, has a low starting voltage, is free of mercury vapor and has a longer life.

[0031] (4) The detection beam can be instantly changed to one having a different wavelength according to the target gas having a different concentration range, and instantaneous correction and feedback can be performed.

[0032] (5) The problem of measurement errors caused by contamination of the quartz glass tube wall as seen in the prior art can be solved.

[0033] In order to better understand the technical features and achievable technical effects of the present invention, better embodiments and detailed descriptions are provided below. [Brief description of the drawings]

[0034] [Figure 1] 2 is a flowchart showing a gas concentration measuring method according to the present invention. [Diagram 2] 1 is a schematic diagram showing a gas concentration measurement device according to the present invention, in which a light source generates a first detection beam. [Diagram 3] 1 is a schematic diagram showing a gas concentration measurement device according to the present invention, in which a light source generates a correction beam; [Figure 4] 2 is a schematic diagram showing a gas concentration measurement device according to the present invention, in which a light source generates a second detection beam. [Diagram 5] 5 is a schematic diagram showing the operation of a light source supply device of the gas concentration measuring device according to the present invention. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0035] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The ratio of each member in the drawings of the embodiment of the present invention is shown for easy understanding of the description, and is not the actual ratio. Furthermore, the dimensional ratio of the assembly shown in the drawings is for explaining each part and its structure, and the present invention is not limited thereto. Meanwhile, for convenience of understanding, the same parts in the following embodiments will be described with the same reference numerals.

[0036] Furthermore, the terms used throughout the specification and claims generally have their ordinary meanings as used in the art, in the context disclosed herein, and in the particular context, unless otherwise specified. Some of the terms used to describe the present invention are explained below or elsewhere in this specification to provide those of ordinary skill in the art with additional guidance regarding the description of the present invention.

[0037] The use of "first," "second," "third," etc. in this article is not intended to denote a specific order or sequence, nor is it used to limit the invention, but is merely used to distinguish between components or operations that are described with the same terminology.

[0038] Secondly, when terms such as "including," "comprising," "having," and "containing" are used in this article, they are all open terms, meaning including but not limited to.

[0039] In the prior art, when measuring the concentration of ozone gas, the warm-up time is too long, the starting voltage is too high, and the light source utilization rate is too low when a low-pressure mercury lamp is used as an ultraviolet light source, and the range of detectable concentrations is too small when a single wavelength is used in the prior art. In order to solve these problems, the present invention proposes a gas concentration measuring device and method for measuring the gas concentration of a target gas (e.g., continuously flowing ozone). The light source of the light source supply device according to the present invention provides at least one ultraviolet wavelength to accurately and quickly measure the ozone concentration. The present invention solves the problem of errors in the light sensing signal measured by the photodetector caused by the dirt or sediment on the quartz glass tube wall in the conventional technology.

[0040] Please refer to Fig. 1 to Fig. 5. Fig. 1 is a flow chart showing a gas concentration measurement method according to the present invention. Fig. 2 is a schematic diagram showing a gas concentration measurement device according to the present invention, in which a light source generates a first detection beam. Fig. 3 is a schematic diagram showing a gas concentration measurement device according to the present invention, in which a light source generates a correction beam. Fig. 4 is a schematic diagram showing a gas concentration measurement device according to the present invention, in which a light source generates a second detection beam. Fig. 5 is a schematic diagram showing the operation of a light source supply device of the gas concentration measurement device according to the present invention.

[0041] 1 and 2 to 5. The gas concentration measurement method according to the present invention includes at least the following steps: step S10 of preparing a gas detection chamber and communicating the gas detection chamber with a gas inlet / outlet passage so that a measurement target gas is present in the gas detection chamber, step S12 of measuring a temperature of the measurement target gas, step S14 of measuring a pressure of the measurement target gas, step S16 of supplying a first detection beam and a correction beam and causing the absorbance of the measurement target gas with respect to the first detection beam to be greater than the absorbance of the measurement target gas with respect to the correction beam, step S17 of dividing the first detection beam into the gas detection chamber and a first detection beam passing through the measurement target gas in the gas detection chamber and a second detection beam not passing through the measurement target gas in the gas detection chamber and a first correction beam passing through the measurement target gas in the gas detection chamber, The method includes a spectroscopic step S18 for dividing the first detection beam into a gas detection chamber and a second correction spectroscopic beam that does not pass through the target gas in the gas detection chamber; a light intensity measurement step S20 for measuring the light intensity of the first detection spectroscopic beam after passing through the target gas and the second detection spectroscopic beam, respectively, and calculating a first detected concentration of the target gas by determining that the change in light intensity in this step is due to the target gas and the gas detection chamber; and a correction step S22 for measuring the light intensity of the first correction spectroscopic beam after passing through the target gas and the second correction spectroscopic beam after passing through the target gas, respectively, and determining that the change in light intensity in the above correction step is due to the gas detection chamber, thereby calculating a corrected concentration of the target gas (i.e., an error due to the gas detection chamber), and subtracting the correction concentration from the first detection concentration to obtain the gas concentration of the target gas. In the present invention, the method for measuring gas concentration has been described using the above-mentioned step order, but the present invention is not limited to this; the order of the steps may be arbitrary, and steps may be added or deleted. As long as the gas concentration of the gas to be measured can be obtained, all of these fall within the scope of protection required by the present invention.

[0042] A gas concentration measurement device 100 according to the present invention includes at least a gas detection chamber 20, a temperature sensing element 30, a pressure sensing element 40, a light source supply device 50, and a light detection device 60. The gas detection chamber 20 communicates with a gas inlet / outlet passage 10, so that a measurement target gas 200 is present in a chamber 22 of the gas detection chamber 20. This makes it possible to measure the gas concentration of the measurement target gas 200. Both ends of the gas inlet / outlet passage 10 are a passage gas inlet 12 and a passage gas outlet 14, respectively, through which the measurement target gas 200 passes. In the present invention, the gas concentration measurement device and method according to the present invention have been described using ozone as the measurement target gas 200, but the present invention is not limited to this, and any gas that can be applied to the gas concentration measurement device and method according to the present invention is all included in the scope of protection required by the present invention.

[0043] A passage gas inlet 12 of the gas inlet / outlet passage 10 communicates with, for example, a measurement target gas supply source (not shown) to introduce a measurement target gas 200 from the measurement target gas supply source into the gas inlet / outlet passage 10. A passage gas outlet 14 of the gas inlet / outlet passage 10 communicates with, for example, a measurement target gas application side (not shown) (for example, but not limited to, a sterilization device or a semiconductor wafer processing chamber). The measurement target gas 200, the measurement target gas supply source, and the measurement target gas application side according to the present invention are not limited to the above, and any measurement target gas supply source and any application that can be realized are all included in the scope of protection claimed by the present invention.

[0044] The gas detection chamber 20 communicates with the gas inlet / outlet passage 10 and is located, for example, between both ends of the gas inlet / outlet passage 10. The gas detection chamber 20 includes a quartz glass tube that employs a transparent material such as quartz glass, and at least the upper and lower ends of the quartz glass tube employ a transparent material such as quartz glass. The gas detection chamber 20 is not limited to quartz glass, and other materials may be adopted, and can be applied to the present invention as long as they have lower absorbance or no absorbance for the detection beam and the correction beam. The gas detection chamber 20 is, for example, a hollow chamber body 24 having a chamber 22. Both ends of the hollow chamber body 24 are a detection gas inlet 26 and a detection gas outlet 28, which communicate with the chamber 22 of the hollow chamber body 24, respectively. The measurement target gas 200 flows, for example, continuously through the chamber 22 of the hollow chamber body 24 of the gas detection chamber 20.

[0045] The temperature sensing element 30 is provided, for example, in the gas inlet / outlet passage 10, and measures the temperature of the measurement target gas 200. The pressure sensing element 40 is provided, for example, in the gas inlet / outlet passage 10, and communicates with the inside of the gas inlet / outlet passage 10, for example, via a pressure sensing gas inlet port 42, thereby measuring the pressure of the measurement target gas 200 inside the gas inlet / outlet passage 10. However, the types, shapes and installation positions of the temperature sensing element 30 and the pressure sensing element 40 are not particularly limited. The temperature sensing element 30 and the pressure sensing element 40 in the embodiments of the present invention may be any commercially available element, and may be, for example, installed in the gas inlet / outlet passage 10, the gas detection chamber 20 and / or the measurement target gas supply source. As long as they can measure the temperature and pressure of the measurement target gas 200, they can all be applied to the present invention.

[0046] The light source supplying device 50 of the gas concentration measuring device 100 according to the present invention includes at least one light source 52 and a spectroscopic element (beam splitter) 54. In the present invention, the spectroscopic element 54 splits the beam from the light source 52 of the light source supplying device 50 into two partial beams, one that passes through the target gas 200 in the gas detection chamber 20 and one that does not pass through the target gas 200 in the gas detection chamber 20. Then, the light detecting device 60 measures the intensities of the two partial beams. When the gas to be measured 200 has a higher absorbance relative to the above beam, the difference in intensity between the two partial beams is caused by the gas to be measured 200 and the gas detection chamber 20, i.e., the attenuation of the light intensity is caused by the gas to be measured 200 and the gas detection chamber 20. However, when the gas to be measured 200 has a lower absorbance relative to the above beam (the lower the absorbance, the better, and even better, no absorbance at all), the difference in intensity between the two partial beams is caused only by the gas detection chamber 20. In other words, the attenuation of the light intensity is caused only by the gas detection chamber 20, and is a light absorption interference error caused, for example, by dirt or deposits on the tube wall of the gas detection chamber 20. In other words, in the present invention, the light source 52 provides beams having two wavelengths (i.e., a beam having a higher absorbance of the gas to be measured and a beam having a lower or no absorbance of the gas to be measured), and the gas concentration of the gas to be detected and measured 200 can be accurately measured by subtracting the light absorption interference error caused by dirt or deposits on the walls of the gas detection chamber 20.

[0047] In the embodiment of the present invention, the light source supplying device 50 is provided, for example, on the first side of the gas detection chamber 20, and provides a first detection beam 55 and a correction beam 56 to the first side of the gas detection chamber 20 by a light source 52. The light source 52 is, for example, a light emitting diode, and is intended to improve the problem that the conventional ultraviolet light source scatters to the surroundings and reduces the utilization rate. The light source supplying device 50 has, for example, a mask 51, and is provided on the first side of the gas detection chamber 20, and the light source 52 and the spectroscopic element 54 are located inside the mask 51, but this is not limited thereto, and the above mask 51 is not limited to a hollow interior or an interior with a core. For example, in the present invention, the first detection beam 55 may be generated by a first light emitting diode (LED) 52a, and the correction beam 56 may be generated by a second light emitting diode 52b. However, the present invention is not limited thereto, and the first detection beam 55 and the correction beam 56 may be generated by a single light emitting diode (LED), for example. One feature of the present invention is that the absorbance of the gas to be measured 200 for the first detection beam 55 is preferably greater than the absorbance of the gas to be measured 200 for the correction beam 56. The greater the difference between these absorbances, the better. For example, the wavelength of the first detection beam 55 is within the absorption wavelength range of the gas to be measured 200, and the wavelength of the correction beam 56 is within or outside the absorption wavelength range of the gas to be measured 200, and the absorbance of the gas to be measured 200 for the first detection beam 55 is greater than the absorbance of the gas to be measured 200 for the correction beam 56. Any of these can be applied to the present invention. The wavelength of the correction beam 56 is preferably outside the absorption wavelength range of the gas to be measured 200. That is, when the correction beam 56 passes through the gas to be measured 200 in the chamber 22 of the gas detection chamber 20, the correction beam 56 is not absorbed by the gas to be measured 200, so that an error due to the gas detection chamber 20 can be obtained. Taking ozone as an example of the gas to be measured, the first detection beam 55 and the correction beam 56 are, for example, ultraviolet rays having different wavelengths, the wavelength range being about 200 nm to about 370 nm, or the correction beam 56 is outside the above wavelength range, and the ultraviolet absorbance of the first detection beam 55 is greater than that of the correction beam 56. The absorption spectrum of ozone is about 200 nm to about 370 nm, and the maximum absorption wavelength is about 254 nm. For this reason, in the present invention, for example, the first detection beam 55 is generated by the first light-emitting diode 52a having an ultraviolet wavelength of 254 nm, which is most absorbed by ozone gas, and the correction beam 56 is generated by the second light-emitting diode 52b having an ultraviolet wavelength of 385 nm, which is very little absorbed by ozone gas. On the other hand, in the present invention, it is preferable to turn on and off the first light emitting diode 52a and the second light emitting diode 52b in an alternating manner (for example, an alternating interval manner, a pulse manner, etc.). Taking the pulse manner as an example, the pulse width is, for example, any value in the range of 0.1 ms to 5 ms, the period is, for example, any value in the range of 0.1 s to 1 s, and the frequency is, for example, any value in the range of 100 Hz to 1 Hz. Taking the interval manner as an example, in the present invention, for example, the first detection beam 55 and the correction beam 56 are repeatedly turned on and off at a certain time interval. The above data are only examples and are not intended to limit the scope of the present invention. Please refer to FIG. 2 and FIG. 5. Section (t1) shows that the first light emitting diode 52a is in an ON state and the second light emitting diode 52b is in an OFF state. Please refer to FIG. 3 and FIG. 5. Section (t2) shows that the first light emitting diode 52a is in an OFF state and the second light emitting diode 52b is in an ON state. The above sections are, for example, time sections. According to the Beer-Lambert law, in the present invention, ozone gas can be detected in the Hartley-Huggins spectrum absorption band (200 nm to 370 nm). For example, in the present invention, the maximum detectable ozone gas concentration is, for example, about 400 g / Nm3. 3 where g is kilogram and Nm 3 is a standard cubic meter. Alternatively, for example, in the present invention, the range in which the ozone gas concentration can be detected may be, for example, 1 ppm to 250 ppm.

[0048] In this manner, the spectroscopic element 54 according to the present invention splits the first detection beam 55 into the first detection beam 55a and the second detection beam 55b as shown in FIG. 2, and splits the correction beam 56 into the first correction beam 56a and the second correction beam 56b as shown in FIG. 3. The first detection beam 55a and the first correction beam 56a pass through the gas detection chamber 20 and the measurement target gas 200 in the gas detection chamber 20. The second detection beam 55b and the second correction beam 56b do not pass through the gas detection chamber 20 and the measurement target gas 200 in the gas detection chamber 20. The spectroscopic element 54 is, for example, an inclined beam splitter, and is provided between the light source 52 and the second light-sensing element 64 (as described below), so that the first detection beam 55a and the first correction beam 56a have the same first optical path, and the second detection beam 55b and the second correction beam 56b have the same second optical path.

[0049] Meanwhile, the optical detection device 60 of the gas concentration measurement device 100 according to the present invention includes at least a first optical sensing element 62 and a second optical sensing element 64, which are located on the second side and the first side of the gas detection chamber 20, respectively. A first detection light beam 55a of the first detection beam 55 (ultraviolet light) from the light source 52 according to the present invention passes through the spectroscopic element 54 along a first optical path, passes through the gas detection chamber 20 employing quartz glass, and then reaches the first optical sensing element 62 to establish a light intensity including the measurement target gas 200 (ozone gas) and the gas detection chamber 20, and a second detection light beam 55b of the first detection beam 55 (ultraviolet light) passes through the spectroscopic element 54 along a second optical path, and reaches the second optical sensing element 64 to establish a light intensity not including the measurement target gas 200 (ozone gas) and the gas detection chamber 20. Similarly, the present invention may establish, for the first corrected fraction 56a and the second corrected fraction 56b of the corrected beam 56 from the light source 52, light intensities including the gas to be measured 200 (ozone gas) and the gas detection chamber 20 and light intensities excluding the gas to be measured 200 (ozone gas) and the gas detection chamber 20, respectively.

[0050] According to the Lambert-Beer law, which is known to those skilled in the art, when a light beam passes through a gas, the absorbance of the light beam is directly proportional to the absorption coefficient, the optical path length, and the gas concentration. Therefore, in the present invention, for example, a first detected concentration and a corrected concentration of the measurement target gas 200 are calculated according to the Lambert-Beer law, and the gas concentration of the measurement target gas 200 can be obtained by subtracting the corrected concentration from the first detected concentration.

[0051] In other words, the first photo-sensing element 62 of the photodetector 60 according to the present invention measures the light intensity of the first detection light beam 55a of the first detection beam 55. The second photo-sensing element 64 of the photodetector 60 according to the present invention measures the light intensity of the second detection light beam 55b of the first detection beam 55. This makes it possible to calculate, for example, a first detected concentration of the target gas 200. Then, by measuring the light intensity of the first correction light beam 56a and the light intensity of the second correction light beam 56b of the correction beam 56, respectively, it is possible to calculate a corrected concentration of the target gas 200. The gas concentration of the target gas 200 can be obtained by subtracting the corrected concentration from the first detected concentration.

[0052] According to the Beer-Lambert law, the formula for calculating the concentration of various gases, CO3, is: TIFF2025044096000002.tif1372. Taking as an example that the measurement target gas 200 is ozone, I is the value of the UV light intensity including ozone gas (first optical path), I0 is the value of the UV light intensity not including ozone gas (second optical path), α is the absorption coefficient of ozone gas, P is the pressure of ozone gas, T is the temperature of ozone gas (in degrees K), psi is the pressure (in pounds per square inch (absolute)), and l is the optical path length of ozone gas.

[0053] Specifically, the gas concentration measurement device 100 according to the present invention further includes, for example, a processing element 70. The processing element 70 is electrically connected to, for example, the light detection device 60, the temperature sensing element 30, and the pressure sensing element 40. The processing element 70 is, for example, a processing control element. The processing element 70 can calculate the first detected concentration Co31 of the measurement target gas 200 by substituting, for example, the temperature of the measurement target gas 200, the pressure of the measurement target gas 200, the light intensity of the first detection light 55a, the light intensity of the second detection light 55b, the optical path length of the measurement target gas 200 in the chamber 22 of the gas detection chamber 20, and the absorption coefficient of the measurement target gas 200 into an equation for calculating the concentration Co3 of various gases according to the Beer-Lambert law. Processing element 70 can further calculate corrected concentration Co32 of measurement target gas 200 by substituting, for example, the temperature of measurement target gas 200, the pressure of measurement target gas 200, the light intensity of first corrected spectroscopic beam 56a, the light intensity of second corrected spectroscopic beam 56b, the optical path length of measurement target gas 200 in chamber 22 of gas detection chamber 20, and the absorption coefficient of measurement target gas 200 into a formula for calculating ozone concentration Co3 according to Lambert-Beer's law. By subtracting corrected concentration Co32 from first detected concentration Co31, gas concentration Co33 of measurement target gas 200 (i.e., Co31-Co32=Co33) can be obtained.

[0054] The light source supplying device 50 according to the present invention further optionally includes a light source control element 80. The light source control element 80 can control the light source 52 of the light source supplying device 50 to provide the first detection beam 55 and the correction beam 56 in an alternating light mode. The light source control element 80 can be, for example, but not limited to, an ultraviolet light source pulse controller. The processing element 70 can be, for example, electrically connected to the light source control element 80. The light mode can be, for example, turned on and off in a pulse manner or an interval manner to provide the first detection beam 55 and the correction beam 56. Meanwhile, the light source 52 can have, for example, one or more light emitting elements, and provide the first detection beam 55 and the correction beam 56. In the present invention, the first detection beam 55 and the correction beam 56 are provided by, for example, a plurality of light-emitting elements (for example, a first light-emitting diode 52a and a second light-emitting diode 52b). The first light-emitting diode 52a generates, for example, the first detection beam 55. The second light-emitting diode 52b generates, for example, the correction beam 56. However, the present invention is not limited thereto. Since a single light-emitting diode (LED) can include a plurality of solid-state light-emitting diode dies of different wavelengths, in the present invention, for example, the first detection beam 55 and the correction beam 56 may be generated by a single light-emitting element (for example, a light-emitting diode). In addition, in the present invention, for example, the brightness and / or wavelength of the first detection beam 55 and the correction beam 56 may be adjusted by a light source control element 80.

[0055] On the other hand, another feature of the present invention is that when the gas concentration Co33 of the measurement target gas 200 obtained by subtracting the correction concentration Co32 from the measured first detection concentration Co31 is lower than the default value, the light source 52 provides at least one second detection beam 57 instead of the first detection beam 55, as shown in FIG. 4. Similarly, the spectroscopic element 54 splits the second detection beam 57 into a third detection light beam 57a and a fourth detection light beam 57b, thereby obtaining the first detection concentration Co31 in the same manner as the first detection beam 55. The wavelength and / or brightness of the second detection beam 57 is different from the wavelength and / or brightness of the first detection beam 55. After subtracting the correction concentration Co32 from the first detection concentration Co31, the gas concentration Co33 of the measurement target gas 200 (i.e., Co31-Co32=Co33) can be obtained. In the present invention, the change of the wavelength or brightness of the detection beam is not limited to the manual mode or the automatic mode. Taking the change of the wavelength of the detection beam in the automatic mode as an example, when the concentration of the measurement target gas 200 (e.g., ozone) is detected to be lower than a certain default value, for example, less than 10% of a preset scale (such as full scale), the light source control element 80, for example, controls the light source 52 to provide the second detection beam 57 by the third light-emitting diode 52c immediately or later. The third light-emitting diode 52c is, for example, a low-concentration ozone absorption light source. However, the present invention is not limited thereto, and for example, the second detection beam 57 may be generated by a single light-emitting diode (LED) instead of the first detection beam 55. The light mode between the second detection beam 57 and the correction beam 56 is, for example, the same as the light mode between the first detection beam 55 and the correction beam 56.

[0056] In the present invention, the concentration of the gas to be measured can be measured accurately in real time by utilizing the characteristic that the same gas to be measured (e.g., ozone) has different absorbances for light rays having different wavelengths, and the characteristic that there is a corresponding relationship between the absorbance of light rays having the same wavelength and the concentration of the gas to be measured (e.g., ozone). The present invention has been described using an example in which the gas to be measured is ozone, but the present invention is not limited to this, and as long as any gas has different absorbances for light rays having different wavelengths, the concentration of this gas can be measured by the gas concentration measurement device and method according to the present invention. The present invention can not only measure the measurement target gas in a flowing or non-flowing state and perform correction, but also measure the measurement target gas that flows continuously and perform correction immediately, for example, by feeding back to a measurement target gas supply source (e.g., an ozone generator or a sterilization device) to generate ozone gas to a sufficient concentration. For example, when the measurement target gas supply source continuously supplies the measurement target gas, the present invention has the effect of being able to measure the concentration of the measurement target gas that flows continuously, accurately, and quickly, and can instantly change to a detection beam having a wavelength corresponding to the measurement target gas having a different concentration range, and can also instantly perform correction. The gas concentration measurement device and method according to the present invention can be applied to the measurement target gas application side of devices that require accurate, stable, and rapid feedback of the ozone concentration, such as sterilization devices, semiconductor wafer manufacturing, or ozone generators.

[0057] The gas concentration measuring device and method according to the present invention have the following advantages. (1) Compared with the conventional technology that uses a low-pressure mercury lamp as an ultraviolet light source, the gas concentration measuring device of the present invention uses a smaller-sized light-emitting diode as an ultraviolet light source, and therefore can accommodate ozone gas having a different concentration range, eliminating the need to replace equipment.

[0058] (2) Using a light-emitting diode as an ultraviolet light source, no warm-up time is required when starting up the equipment. By turning it on and off in a pulsed manner, an ultraviolet light source can be provided, allowing for instant correction.

[0059] (3) By using a light-emitting diode as the ultraviolet light source, the concentration of the continuously flowing target gas can be measured instantly, accurately and quickly. It does not require warm-up, has a low starting voltage, is free of mercury vapor and has a longer life.

[0060] (4) The detection beam can be instantly changed to one having a different wavelength according to the target gas having a different concentration range, and instantaneous correction and feedback can be performed.

[0061] (5) The problem of measurement errors caused by contamination of the quartz glass tube wall as seen in the prior art can be solved.

[0062] The above description is illustrative only and not limiting. Any equivalent modifications or variations thereto that do not depart from the spirit and scope of the present invention are intended to be within the scope of the claims. [Explanation of symbols]

[0063] 10 Gas passage 12 Passage gas inlet 14 Passage gas outlet 20 Gas Detection Chamber 22 Chamber 24 Hollow chamber body 26 Detection gas inlet 28 Detection gas outlet 30 Temperature sensing element 40 Pressure sensing element 42 Pressure-sensing gas-filled port 50 Light source supply device 51 Mask 52 Light source 52a First light emitting diode 52b Second light emitting diode 52c Third Light Emitting Diode 54 Spectroscopic element 55 First detection beam 55a First detection spectroscopy 55b Second detection spectroscopy 56 Correction Beam 56a First correction spectroscopy 56b Second correction spectroscopy 57 Second detection beam 60 Light detection device 62 First light sensing element 64 Second light sensing element 70 Processing element 80 Light source control element 100 Gas concentration measuring device 200 Gases to be measured S10, S12, S14, S16, S18, S20, S22 steps t1, t2 Section

Claims

1. A gas concentration measurement device for measuring a gas concentration of a measurement target gas, comprising: one of the chambers being a gas detection chamber having the gas to be measured by communicating with the gas inlet / outlet passage; a temperature sensing element for detecting a temperature of the measurement target gas; a pressure sensing element for detecting the pressure of the measurement target gas; a light source supplying device provided on a first side of the gas detection chamber for generating a first detection beam and a correction beam, the light source supplying device including: at least one light source having an absorbance for the first detection beam that is greater than an absorbance for the correction beam of the measurement target gas; and a spectroscopic element for dividing the first detection beam into a first detection spectrum and a second detection spectrum and dividing the correction beam into a first correction spectrum and a second correction spectrum, the first detection spectrum and the first correction spectrum passing through the gas detection chamber and the measurement target gas in the gas detection chamber, and the second detection spectrum and the second correction spectrum not passing through the gas detection chamber and the measurement target gas in the gas detection chamber; and a photodetection device comprising at least a first photodetecting element and a second photodetecting element located on the second side and the first side of the gas detection chamber, respectively, which calculate a first detected concentration of the target gas by measuring the light intensity of the first detection spectrum and the light intensity of the second detection spectrum of the first detection beam, respectively, and calculate a corrected concentration of the target gas by measuring the light intensity of the first correction spectrum and the light intensity of the second correction spectrum of the correction beam, respectively, and obtain the gas concentration of the target gas after subtracting the corrected concentration from the first detected concentration. Gas concentration measuring device.

2. 2. The gas concentration measurement device of claim 1, wherein both ends of the gas inlet / outlet passage are a passage gas inlet and a passage gas outlet, respectively, the passage gas inlet is an inlet for the gas to be measured, the passage gas outlet is an outlet for the gas to be measured, the gas detection chamber is a hollow chamber body having the chamber, both ends of the hollow chamber body have a detection gas inlet and a detection gas outlet, respectively, the detection gas inlet and the detection gas outlet are connected to the chamber of the hollow chamber body, and the measurement target gas flows continuously through the chamber of the hollow chamber body of the gas detection chamber.

3. 2. The gas concentration measurement device according to claim 1, further comprising a processing element that calculates the first detected concentration of the target gas based on the temperature of the target gas, the pressure of the target gas, the light intensity of the first detection spectrum, the light intensity of the second detection spectrum, an optical path length of the target gas in the gas detection chamber, and an absorption coefficient of the target gas, and the processing element further calculates the corrected concentration of the target gas based on the temperature of the target gas, the pressure of the target gas, the light intensity of the first correction spectrum, the light intensity of the second correction spectrum, the optical path length of the target gas in the gas detection chamber, and the absorption coefficient of the target gas.

4. 2. The gas concentration measuring device according to claim 1, wherein the gas to be measured is ozone, and the first detection beam and the correction beam from the light source are ultraviolet rays.

5. 2. The gas concentration measurement device according to claim 1, wherein the spectroscopic element is an inclined beam splitter, and the spectroscopic element causes the first detection spectroscopic light and the first correction spectroscopic light to have the same first optical path, and the second detection spectroscopic light and the second correction spectroscopic light to have the same second optical path.

6. 2. The gas concentration measuring device according to claim 1, wherein the gas detection chamber is a quartz glass tube.

7. 2. The gas concentration measurement device of claim 1, wherein the wavelength of the first detection beam is within an absorption wavelength range of the gas to be measured, and the wavelength of the correction beam is outside the absorption wavelength range of the gas to be measured, thereby correcting optical absorption interference errors caused by the gas detection chamber.

8. 2. The gas concentration measurement apparatus of claim 1, wherein the light source supply device further comprises a light source control element for controlling the light source of the light source supply device to provide the first detection beam and the correction beam in an alternating light mode.

9. 9. The gas concentration measurement apparatus of claim 8, wherein the alternating light mode is on and off in a pulsed or interval format to provide the first detection beam and the correction beam.

10. 9. The gas concentration measurement device according to claim 1, wherein when the gas concentration of the target gas obtained by subtracting the correction concentration from the first detected concentration is lower than a default value, the light source supplies at least one second detection beam instead of the first detection beam, and the wavelength and / or brightness of the second detection beam is different from the wavelength and / or brightness of the first detection beam.

11. 11. The gas concentration measurement device according to claim 10, wherein the light source has one or more light emitting elements to provide the first detection beam and the correction beam.

12. A gas concentration measurement method for measuring a gas concentration of a measurement target gas, comprising: providing a gas detection chamber, the gas detection chamber being in communication with a gas inlet / outlet passage such that the gas to be measured is present within the gas detection chamber; a temperature measuring step of detecting a temperature of the measurement target gas; a pressure measuring step of detecting a pressure of the measurement target gas; providing a first detection beam and a correction beam, wherein an absorbance of the gas to be measured with respect to the first detection beam is greater than an absorbance of the gas to be measured with respect to the correction beam; a spectroscopic step of splitting the first detection beam into a first detection light beam passing through the gas detection chamber and a second detection light beam not passing through the gas detection chamber, and splitting the correction beam into a first correction light beam passing through the gas detection chamber and the gas detection chamber, and a second correction light beam not passing through the gas detection chamber and the gas detection chamber; a light intensity measuring step of calculating a first detected concentration of the measurement target gas by measuring a light intensity of the first detection light beam and a light intensity of the second detection light beam of the first detection beam; a correction step of calculating a corrected concentration of the measurement target gas by measuring the light intensity of the first correction spectral component and the light intensity of the second correction spectral component of the correction beam, and obtaining the gas concentration of the measurement target gas by subtracting the corrected concentration from the first detected concentration, Gas concentration measurement method.

13. 13. The method of claim 12, wherein the gas to be measured flows continuously through the gas detection chamber.

14. 13. The gas concentration measurement method according to claim 12, wherein the light intensity measuring step further includes calculating the first detected concentration of the target gas from the temperature of the target gas, the pressure of the target gas, the light intensity of the first detection light, the light intensity of the second detection light, an optical path length of the target gas in the gas detection chamber, and an absorption coefficient of the target gas, and the correction step further includes calculating the corrected concentration of the target gas from the temperature of the target gas, the pressure of the target gas, the light intensity of the first correction light, the light intensity of the second correction light, the optical path length of the target gas in the gas detection chamber, and the absorption coefficient of the target gas.

15. 13. The gas concentration measurement method according to claim 12, wherein the gas to be measured is ozone, and the first detection beam and the correction beam are ultraviolet rays.

16. 13. The gas concentration measurement method according to claim 12, wherein the spectroscopic step is characterized in that the first detection spectroscopic beam and the first correction spectroscopic beam have a same first optical path, and the second detection spectroscopic beam and the second correction spectroscopic beam have a same second optical path, by a spectroscopic element.

17. 13. The gas concentration measuring method according to claim 12, wherein the gas detection chamber is a quartz glass tube.

18. 13. The gas concentration measurement method according to claim 12, wherein a wavelength of the first detection beam is within an absorption wavelength range of the gas to be measured, and a wavelength of the correction beam is outside the absorption wavelength range of the gas to be measured, thereby correcting an optical absorption interference error due to a material of the gas detection chamber.

19. 13. The method of claim 12, further comprising controlling a light source using a light source control element to provide the first detection beam and the correction beam in an alternating light mode.

20. 20. The method of claim 19, wherein the alternating light modes are on and off in a pulsed or interval fashion to provide the first detection beam and the correction beam.

21. 20. The gas concentration measurement method according to claim 12 or 18, characterized in that, when the gas concentration of the target gas obtained by subtracting the correction concentration from the first detected concentration is lower than a default value, at least one second detection beam is supplied instead of the first detection beam, and a wavelength and / or brightness of the second detection beam is different from a wavelength and / or brightness of the first detection beam.

22. 22. The method of claim 21, further comprising providing the first detection beam and the correction beam with a light source having one or more light emitting elements.

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