Presumption method

Abstract

Improve the accuracy of estimating the amount of gas released from the measurement object. [Solution] In the present disclosure, the gas concentration is measured at a predetermined measurement height in the measurement object, and the amount of gas released from the measurement object is estimated from the measured gas concentration based on a predetermined correlation between the amount of gas released from the measurement object and the gas concentration at the predetermined measurement height.

Description

[Technical Field]

[0001] The present disclosure relates to estimation methods. [Background technology]

[0002] The gas concentration flux measurement device of Patent Document 1 includes a laser light source, a laser output control device, a wavelength modulation control device, a first light receiving device, a first DC component detector, a first wavelength modulation demodulator, an optical system, a reference cell, a second light receiving device, a second DC component detector, a second wavelength modulation demodulator, a third wavelength modulation demodulator, an analyzer, an adder, a temperature measurement means, a pressure measurement means, and a flow velocity measurement means that directly measures two horizontal flow velocity components and a vertical flow velocity component of a gas flow in a measurement region and outputs these measurement signals to the analyzer. In the gas concentration flux measurement device of Patent Document 1, the analyzer performs an analysis based on the eddy correlation law using signals input from the flow velocity measurement means and calculates the momentum flux and concentration of the gas to be measured using the analysis results.

[0003] Non-Patent Documents 1 and 2 disclose methods for estimating the amount of methane emitted from rice paddies using a laser methane detector. In the methods of Non-Patent Documents 1 and 2, for example, two laser methane detectors are used to measure methane concentrations at two different altitudes, and the amount of methane emitted from the rice paddy is estimated using the gradient method. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-106546 [Non-patent literature]

[0005] [Non-Patent Document 1] Kochi University of Technology Graduation Thesis Abstract Measurement of methane concentration and emission amount in rice paddies using a portable laser methane detector - Examination of the feasibility through field observation - 1140221 Maki Kawakami [Non-patent document 2] Kochi University of Technology Graduation Thesis Abstract Measurement of methane concentration and emission amount in rice paddies using a laser methane detector - Examination of observation methods - 1150199 Ai Emura Summary of the Invention [Problem to be solved by the invention]

[0006] Here, in the conventional technologies of Non-Patent Document 1 and Non-Patent Document 2, the actual amount of methane produced and the methane concentration are unknown, and only the amount of methane produced can be estimated. Therefore, the accuracy of the estimation cannot be verified, and there are issues with the accuracy of the estimation.

[0007] The present disclosure aims to improve the accuracy of estimating the amount of gas released from a measurement object. [Means for solving the problem]

[0008] In the first aspect, the gas concentration is measured at a predetermined measurement height in the measurement object, and the amount of gas released from the measurement object is estimated from the measured gas concentration based on a predetermined correlation between the amount of gas released from the measurement object and the gas concentration at the predetermined measurement height.

[0009] In this way, in the first aspect, the amount of gas released is estimated from the gas concentration measured in the object to be measured based on a correlation obtained in advance, thereby improving the accuracy of estimating the amount of gas released from the object to be measured compared to conventional technology.

[0010] In the second aspect, in the first aspect, a predetermined amount of test gas is released in an environment simulating the environment of the measurement object, and the gas concentration of the test gas is measured at the predetermined measurement height, and the correlation is determined.

[0011] In this way, in the second aspect, a test gas of a preset amount is released in an environment simulating the environment of the measurement object, and then the gas concentration is measured at a predetermined measurement height to determine the correlation, thereby obtaining data showing a highly accurate correlation. As a result, the estimation accuracy of the amount of gas released from the measurement object can be improved.

[0012] In a third aspect, in the second aspect, measurement is continued until the gas concentration of the test gas at the predetermined measurement height reaches a steady state, and the correlation is found.

[0013] In this way, in the third aspect, measurement is performed until the gas concentration of the test gas at a predetermined measurement height reaches a steady state, so data showing a highly accurate correlation can be obtained, thereby improving the accuracy of estimating the amount of gas released from the measurement object.

[0014] In the fourth aspect, in the second aspect, a predetermined amount of test gas is released from the bottom of a cylinder with an open top, and the gas concentration of the test gas is measured at the specified measurement height to determine the correlation.

[0015] In this way, in the fourth aspect, a preset amount of test gas is released from the bottom of the open-topped cylinder, creating an environment similar to that of the measurement target. This allows for the acquisition of data showing a highly accurate correlation. As a result, the estimation accuracy of the amount of gas released from the measurement target can be improved.

[0016] In a fifth aspect, in the fourth aspect, a preset amount of test gas is released through a dispersion part that is provided in the lower part of the cylindrical body and that disperses the test gas.

[0017] In this way, in the fifth aspect, a preset amount of test gas is released through a dispersion unit that disperses the test gas, thereby creating an environment similar to the environment of the measurement target. This makes it possible to obtain data that shows a highly accurate correlation. As a result, the estimation accuracy of the amount of gas released from the measurement target can be improved.

[0018] In a sixth aspect, in the fourth aspect, the cylindrical body has a height equal to or greater than the predetermined measurement height and is formed of a material that transmits a laser that is absorbed by the test gas, and the laser is irradiated at the predetermined measurement height from outside the cylindrical body so that the laser passes through the cylindrical body, and the gas concentration of the test gas is measured.

[0019] In this way, in the sixth aspect, since the cylindrical body has a height equal to or greater than a predetermined measurement height, an environment similar to that of the measurement target can be created. Furthermore, the gas concentration of the test gas is measured by irradiating the cylindrical body with a laser at a predetermined measurement height so that the laser passes through the cylindrical body from the outside. This makes it possible to obtain data showing a highly accurate correlation. As a result, the estimation accuracy of the amount of gas released from the measurement target can be improved. [Effects of the Invention]

[0020] The present disclosure has the above configuration, and therefore can improve the accuracy of estimating the amount of gas released from the measurement object. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 1 is a schematic diagram illustrating an example of a measurement device according to an embodiment of the present invention. [Figure 2] FIG. 1 is a schematic diagram illustrating an example of a test apparatus according to an embodiment of the present invention. [Figure 3] FIG. 1 is a block diagram illustrating an example of a processing device according to an embodiment of the present invention. [Figure 4] FIG. 2 is a block diagram showing an example of the functional configuration of a processor in the processing device according to the present embodiment. [Figure 5] 10 is a graph showing a correlation according to the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0022] An example of an embodiment of the present invention will be described below with reference to the drawings.

[0023] <Method for estimating gas release amount> A method for estimating the amount of released gas according to this embodiment will be described.

[0024] 1, the method for estimating the amount of released gas according to this embodiment measures the gas concentration at a predetermined measurement height H in the measurement target 100, and estimates the amount of released gas from the measurement target 100 from the measured gas concentration based on a predetermined correlation between the amount of released gas from the measurement target 100 and the gas concentration at the predetermined measurement height H. Below, the measurement target 100, the gas 110, a specific estimation method, the effects of this embodiment, and modified examples will be described.

[0025] <100 Measurement Targets> The measurement target 100 is an object whose gas concentration is to be measured. The measurement target 100 can be, for example, the ground, the surface of water, or the like that emits gas 110. That is, the measurement target 100 can be, for example, an object that has a surface facing upward and emits gas from that surface into an open space facing upward. Specifically, the measurement target 100 can be, for example, a rice paddy, a garbage landfill, or the like. Note that the measurement target of the present disclosure is not limited to the above-mentioned objects, and can be any object that emits gas.

[0026] <Gas 110> The gas 110 is a gas emitted from the measurement target 100, and its concentration is measured at a predetermined measurement height H in the measurement target 100. An example of the gas 110 is a greenhouse gas. An example of the greenhouse gas is methane gas. Note that the gases in the present disclosure are not limited to those mentioned above, and any gas that is emitted from the measurement target and can be measured is applicable.

[0027] <Specific estimation method> Specifically, the estimation method includes a preparation step, a measurement step, and an estimation step. Each step will be described below.

[0028] <Preparation process> In the preparation step, a correlation (hereinafter sometimes referred to as correlation S) between the amount of gas released from the measurement object 100 and the gas concentration at a predetermined measurement height H is obtained in advance. In this embodiment, the correlation S is obtained using, for example, a test device 20 shown in FIG.

[0029] The test device 20 has a discharge device 21 that discharges a test gas and a measurement device 30 that measures the gas concentration of the test gas. The test gas used has the same components as the gas 110. Therefore, if the type of gas 110 discharged from the measurement object 100 changes, the test gas will also change accordingly.

[0030] The release device 21 releases a preset amount of test gas under an environment simulating the environment of the measurement target 100. Specifically, the release device 21 has a cylindrical body 22, a dispersion section 28, a gas release section 23, and a flow meter 26.

[0031] The cylindrical body 22 is formed in a cylindrical shape (for example, a cylindrical shape) with both axial ends open. The cylindrical body 22 is disposed with its axial direction aligned in the up-and-down direction. The cylindrical body 22 has a height equal to or greater than a predetermined measurement height H.

[0032] The cylindrical body 22 is formed of a transparent material that transmits the laser from the measuring device 30. A material with a transmittance of, for example, 90% or more is used as the transparent material. Specific examples of the transparent material include acrylic and glass. A reflective material 27 that reflects the laser from the measuring device 30 is attached to the inner wall of the cylindrical body 22. This reflective material 27 is arranged along the axial direction at a portion of the circumferential direction of the cylindrical body 22. The reflective material 27 has a reflective surface 27A that faces the inner circumferential side of the cylindrical body 22 (inward in the radial direction).

[0033] The internal space of the cylindrical body 22 is closed at the sides by a side wall 22A arranged around the axial direction of the cylindrical body 22, and is open at the top.

[0034] The gas release section 23 releases the test gas from below the cylindrical body 22 into the interior of the cylindrical body 22. Specifically, the gas release section 23 has a storage section 24 that stores the test gas, and a connection section 25 that connects the storage section 24 and the cylindrical body 22.

[0035] The storage section 24 is configured, for example, by a gas cylinder, and stores compressed test gas therein. The storage section 24 has a discharge port 24A for discharging the test gas therein, and the discharge port 24A is provided with an on-off valve 24B.

[0036] The connecting part 25 is configured, for example, by a connecting pipe that connects the storage part 24 and the cylindrical body 22. One end of the connecting part 25 is connected, for example, to the discharge port 24A via the opening / closing valve 24B of the storage part 24. The other end of the connecting part 25 is connected, for example, to the lower end of the cylindrical body 22.

[0037] Flow meter 26 is provided in connection portion 25 and measures the flow rate of gas released from storage portion 24 to cylindrical body 22. In gas release portion 23, the opening of on-off valve 24B is adjusted based on flow meter 26 to release a preset amount of test gas.

[0038] The dispersion section 28 has the function of dispersing the test gas released from the connection section 25 to the cylindrical body 22. The dispersion section 28 is provided at the bottom of the cylindrical body 22. In the release device 21, the test gas from the gas release section 23 is released into the inside of the cylindrical body 22 via the dispersion section 28. Specifically, the dispersion section 28 is attached to the lower end of the inside of the cylindrical body 22 so as to close the lower opening of the cylindrical body 22. The dispersion section 28 is made of a porous material such as a sponge. When a porous material is used for the dispersion section 28, materials with different opening rates and pore sizes may be stacked in the axial direction of the cylindrical body 22.

[0039] The measuring device 30 is a device that measures the gas concentration of the test gas released into the cylindrical body 22 at a predetermined measurement height H. The measuring device 30 has, for example, an irradiation unit 31, a light receiving unit 32, and a processing device 40.

[0040] The irradiating unit 31 and the light receiving unit 32 are provided on the outer periphery of the cylindrical body 22, facing the reflecting surface 27A of the reflecting material 27. The irradiating unit 31 and the light receiving unit 32 are disposed at a predetermined measurement height H.

[0041] The irradiation unit 31 irradiates the cylindrical body 22 from the outside with a laser at a predetermined measurement height H so that the laser passes through the cylindrical body 22. Specifically, the irradiation unit 31 irradiates the laser in the radial direction (e.g., horizontal direction) of the cylindrical body 22 toward the reflecting surface 27A of the reflector 27. In this embodiment, the irradiation unit 31 irradiates a laser having a wavelength in a range where absorption occurs in the test gas.

[0042] For example, the optical absorption spectrum of methane has a relatively high absorptivity in the infrared wavelength range from 1 μm to 5 μm, for example, near wavelengths of 1.6 μm and 3.3 μm. When methane is used as the test gas, the irradiation unit 31 can be configured to irradiate a laser having a wavelength near 1.6 μm or 3.3 μm, for example.

[0043] The laser emitted from the irradiation unit 31 passes through the side wall of the cylinder 22 and the internal space of the cylinder 22 in this order, is reflected by the reflector 22R, passes through the internal space of the cylinder 22 and the side wall of the cylinder 22 in this order, and reaches the light receiving unit 32. Then, the measuring device 30 measures the gas concentration based on the light received by the light receiving unit 32. The measuring device 30 continues measuring until the gas concentration of the test gas at a predetermined measurement height H reaches a steady state.

[0044] The irradiating unit 31 and the light receiving unit 32 may be arranged at a plurality of heights, each of which is a predetermined measurement height H, as shown in FIG.

[0045] Here, the processing device 40 has the functions of a computer, and as shown in FIG. 3, has a processor 41, a memory 42, a storage 43, an input unit 44, a communication unit 45, and a display unit 46.

[0046] The processor 41 may be, for example, a general-purpose processor such as a CPU (Central Processing Unit). The processor 41 may be a dedicated processor configured with a circuit designed specifically for executing a specific process. The processor 41 is not limited to being configured with a single processor, but may be configured with multiple processors that are physically separated from one another.

[0047] The storage 43 stores various programs and various data, and is specifically realized by a recording device such as a hard disk drive (HDD), a solid state drive (SSD), or a flash memory.

[0048] The memory 42 is a work area for the processor 41 to execute various programs, and temporarily stores various programs or various data when the processor 41 executes processing. The processor 41 reads the various programs from the storage 43 into the memory 42, and executes the programs using the memory 42 as a work area.

[0049] The input unit 44 is a component into which the user inputs various information and instructions. Specifically, the input unit 44 is composed of, for example, a pointing device such as a mouse and input keys such as a keyboard.

[0050] The input unit 44 is not limited to a pointing device and input keys, but may be configured with a touch panel or the like, and may be anything that can input various types of information and instructions.

[0051] The communication unit 45 is a connection unit (communication interface) for communicating with other devices. Specifically, the communication unit 45 communicates with other devices through at least one of a wired and wireless communication line.

[0052] The display unit 46 notifies the user of the presentation information by displaying the presentation information to be presented to the user. The display unit 46 is configured, for example, with a liquid crystal display, an organic EL (Electro Luminescence) display, or the like.

[0053] The processing device 40 acquires concentration data indicating the gas concentration measured by the measurement device 30. Then, based on the concentration data, the processing device 40 preliminarily determines a correlation S between the amount of gas released from the measurement target 100 and the gas concentration at a predetermined measurement height H. The processing device 40 stores correlation data indicating this correlation S in the storage device 34.

[0054] In the processing device 40, the processor 41 executes the processing program 43A to realize various functions. The following describes the functional configuration realized by the cooperation of the processor 41 as a hardware resource and the processing program 43A as a software resource. Figure 4 is a block diagram showing the functional configuration of the processor 41.

[0055] As shown in FIG. 4, in the processing device 40, the processor 41 executes a processing program 43A to function as an acquisition unit 41A and a processing unit 41B.

[0056] The acquisition unit 41A acquires concentration data indicating the gas concentration measured by the measurement device 30. The processing unit 41B preliminarily calculates a correlation S between the amount of gas released from the measurement target 100 and the gas concentration at a predetermined measurement height H based on the concentration data. For example, correlation data indicating the correlation S as shown in FIG. 5 is obtained. The processing unit 41B stores the correlation data indicating the correlation S in the storage 43.

[0057] <Measurement process> The measurement process is a process of measuring the gas concentration at a predetermined measurement height H in the measurement target 100. In the measurement process, the gas concentration is measured using a measurement device 50. As shown in FIG. 1 , the measurement device 50 has a laser irradiation unit 14, a laser receiving unit 16, and a processing unit 19.

[0058] The predetermined measurement height H is set, for example, at a position higher than any obstacles that may be placed on the measurement target 100 and that may prevent the laser irradiation, and at a position close to the surface of the measurement target 100 from which the gas 110 is emitted. If the measurement target 100 is a rice paddy, for example, the predetermined measurement height H is set at a position higher than the rice plants that serve as obstacles, and close to the surface of the paddy. If the measurement target 100 is a rice paddy, the measurement height H may be changed depending on the presence or absence of rice plants and the growth of the rice plants, or multiple measurement heights H may be set.

[0059] <Laser irradiation unit 14> The laser irradiation unit 14 has a function of irradiating a measurement laser. Specifically, the laser irradiation unit 14 irradiates a laser toward the space above the measurement target 100 at a predetermined measurement height H. In this embodiment, the laser irradiation unit 14 irradiates a detection laser having a wavelength corresponding to the optical absorption spectrum of the gas to be irradiated.

[0060] For example, in the case of methane, the light absorption spectrum has a relatively high absorptivity in the infrared wavelength range from 1 μm to 5 μm, for example, near wavelengths of 1.6 μm and 3.3 μm. Therefore, when the gas to be measured is methane, the irradiation unit 31 can be configured to irradiate a laser having a wavelength near 1.6 μm or 3.3 μm, for example.

[0061] In this way, the laser irradiation unit 14 irradiates a detection laser having a wavelength corresponding to the optical absorption spectrum of the gas to be measured. Therefore, when a gas other than methane is to be measured 100, the laser irradiation unit 14 is configured to irradiate a measurement laser having a wavelength with a relatively high absorptance in the optical absorption spectrum of the gas.

[0062] <Laser receiving unit 16, processing unit 19> 2 receives the light reflected by the reflector 18. The processor 19 calculates the total amount of methane between the laser irradiator 14 and the reflector 18 based on the laser intensity of the measurement laser received by the laser receiver 16. Specifically, the processor 19 calculates the gas concentration (ppm) based on the laser intensity.

[0063] The processing unit 19 includes a control unit (control board) having a recording unit including a storage device or the like in which a program is recorded and a processor that operates according to the program. The processing unit 19 transmits concentration data indicating the calculated gas concentration to the processing device 40.

[0064] <Estimated process> The estimation process is a process of estimating the amount of gas released from the measurement object 100 from the measured gas concentration based on a correlation S determined in advance between the amount of gas released from the measurement object 100 and the gas concentration at a predetermined measurement height H. In the estimation process, the processing device 40 estimates the amount of gas released based on the gas concentration measured by the measurement device 50 in the measurement process.

[0065] As shown in the figure, in the processing device 40, the processor 41 executes an estimation program 43B to function as an acquisition unit 41A and an estimation unit 41C.

[0066] The acquisition unit 41A acquires concentration data indicating the gas concentration measured by the measurement device 50. The estimation unit 41C estimates the amount of gas released from the measurement target 100 based on the concentration data from a correlation S between the amount of gas released from the measurement target 100 and the gas concentration at a predetermined measurement height H.

[0067] The display unit 46 displays the amount of released gas estimated by the estimation unit 41C, thereby presenting the estimation result in the processing device 40 to the outside (specifically, to the user).

[0068] <Actions and Effects According to This Embodiment> According to this embodiment, the gas concentration is measured at a predetermined measurement height H in the measurement object 100, and the amount of gas released from the measurement object 100 is estimated from the measured gas concentration based on a predetermined correlation S between the amount of gas released from the measurement object 100 and the gas concentration at the predetermined measurement height H.

[0069] In this way, in this embodiment, the amount of gas released is estimated from the gas concentration measured in the measurement object 100 based on the correlation S obtained in advance, thereby improving the accuracy of estimating the amount of gas released from the measurement object 100 compared to conventional technology.

[0070] Furthermore, in this embodiment, a test gas with a preset gas release amount is released in an environment simulating the environment of the measurement target 100, and the gas concentration of the test gas is measured at the predetermined measurement height to determine the correlation S. Therefore, data showing a highly accurate correlation S can be obtained. As a result, the estimation accuracy of the gas release amount from the measurement target 100 can be improved.

[0071] Furthermore, in this embodiment, measurement is performed until the gas concentration of the test gas at a predetermined measurement height H reaches a steady state. Therefore, data showing a highly accurate correlation S can be obtained. As a result, the estimation accuracy of the amount of gas released from the measurement object 100 can be improved.

[0072] In addition, in this embodiment, a preset amount of test gas is released from below the cylindrical body 22, which has an open top, and the gas concentration of the test gas is measured at a predetermined measurement height H. This makes it possible to create an environment that is similar to the environment of the measurement object 100. Therefore, data showing a highly accurate correlation S can be obtained. As a result, the estimation accuracy of the amount of gas released from the measurement object 100 can be improved.

[0073] Furthermore, in this embodiment, a preset amount of test gas is released through a dispersion unit that disperses the test gas, and the gas concentration of the test gas is measured at a predetermined measurement height H. This makes it possible to create an environment that is similar to the environment of the measurement object 100. Therefore, data showing a highly accurate correlation S can be obtained. As a result, the estimation accuracy of the amount of gas released from the measurement object 100 can be improved.

[0074] Furthermore, in this embodiment, since the cylindrical body 22 has a height equal to or greater than the predetermined measurement height H, an environment similar to that of the measurement target 100 can be created. Furthermore, the gas concentration of the test gas is measured by irradiating the cylindrical body 22 with a laser at the predetermined measurement height H from the outside so that the laser passes through the cylindrical body 22. This makes it possible to obtain data showing a highly accurate correlation S. As a result, the estimation accuracy of the amount of gas released from the measurement target 100 can be improved.

[0075] <Modification> In this embodiment, the correlation S is calculated using the test device 20, but this is not limiting. For example, the correlation S may be calculated based on the results of measurement of the actual measurement target 100. Furthermore, the configuration of the test device 20 is not limited to the one described above, and various configurations may be applied.

[0076] The present invention is not limited to the above-described embodiment, and various modifications, changes, and improvements are possible without departing from the spirit of the present invention. For example, the above-described modified examples may be appropriately combined to form a configuration.

[0077] <Additional Notes> [Aspect 1] Measure the gas concentration at a predetermined measurement height in the measurement target, The amount of gas released from the measurement object is estimated from the measured gas concentration based on a correlation obtained in advance between the amount of gas released from the measurement object and the gas concentration at the predetermined measurement height. Estimation method. [Aspect 2] Releasing a test gas at a predetermined gas release amount under an environment simulating the environment of the measurement target; measuring the gas concentration of the test gas at the predetermined measurement height; Calculating the correlation 2. The estimation method according to claim 1. [Aspect 3] Measure the gas concentration of the test gas at the predetermined measurement height until it reaches a steady state; Calculating the correlation The estimation method according to aspect 2. [Aspect 4] A preset amount of test gas is released from the bottom of the open-topped cylinder. measuring the gas concentration of the test gas at the predetermined measurement height; Calculating the correlation The estimation method according to aspect 2 or aspect 3. [Aspect 5] A preset amount of test gas is released through a dispersion section that is provided at the bottom of the cylinder and that disperses the test gas. 5. The estimation method according to aspect 4. [Aspect 6] the cylinder has a height equal to or greater than the predetermined measurement height and is made of a material that transmits laser light that is absorbed by the test gas; The laser is irradiated from the outside of the cylindrical body at the predetermined measurement height so that the laser passes through the cylindrical body, and the gas concentration of the test gas is measured. The estimation method according to aspect 4 or aspect 5. [Explanation of symbols]

[0078] 14 Laser irradiation unit 16 Laser receiving unit 18 Reflector 19 Processing section 20 Test Equipment 21 Release device 22 Cylinder 22A side wall 22R reflective material 23 Gas release section 24 Storage section 24A outlet 24B On-off valve 25 Connection 26 Flow meter 27 Reflective material 27A reflective surface 28 Dispersion section 30 Measuring Equipment 31 Irradiation unit 32 Light receiving part 34 Storage device 40 Processing equipment 41 processors 41A Acquisition Department 41B Processing section 41C Estimation part 42 memory 43 Storage 43A Processing Program 43B Estimation Program 44 Input section 45 Communications Department 46 Display section 50 Measuring Equipment 100 Measurement Targets 110 Gas

Claims

1. Measure the gas concentration at a predetermined measurement height in the measurement target, The amount of gas released from the measurement object is estimated from the measured gas concentration based on a correlation obtained in advance between the amount of gas released from the measurement object and the gas concentration at the predetermined measurement height.

1. A method of estimation comprising: Releasing a test gas at a predetermined gas release amount under an environment simulating the environment of the measurement target; measuring the gas concentration of the test gas at the predetermined measurement height; Calculating the correlation Estimation method.

2. Measurement is performed until the gas concentration of the test gas at the predetermined measurement height reaches a steady state, Calculating the correlation The estimation method according to claim 1 .

3. A test gas is released from the bottom of a cylinder whose top is open, at a preset gas release rate, measuring the gas concentration of the test gas at the predetermined measurement height; Calculating the correlation The estimation method according to claim 2 .

4. A test gas is released in a predetermined amount through a dispersion part that is provided at the bottom of the cylindrical body and that disperses the test gas. The estimation method according to claim 3 .

5. The cylindrical body has a height equal to or greater than the predetermined measurement height and is formed of a material that transmits laser light that is absorbed by the test gas; The laser is irradiated from the outside of the cylindrical body at the predetermined measurement height so that the laser passes through the cylindrical body, and the gas concentration of the test gas is measured. The estimation method according to claim 3 .

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