WO2020059100A1

WO2020059100A1 - Measuring device and measuring method

Info

Publication number: WO2020059100A1
Application number: PCT/JP2018/034955
Authority: WO
Inventors: 修一山田; 将徳中野; 亮介辻尾
Original assignee: 大塚電子株式会社
Priority date: 2018-09-21
Filing date: 2018-09-21
Publication date: 2020-03-26
Also published as: JPWO2020059100A1; JP7108327B2

Abstract

The present invention comprises: a first measuring unit (502) which measures a concentration of a component gas of each of a first gas to be measured and a second gas to be measured collected as gases to be measured; a concentration adjusting unit (504) which adjusts the concentration of the second gas to be measured such that the concentration of the component gas of the first gas to be measured and the concentration of the component gas of the second gas to be measured by the first measuring unit are the same; a pressurizing control unit (506) which performs pressurization with a predetermined force; a pressure measuring unit (508) which measures a pressure value of a gas to be measured having at least a higher concentration of the component gas; a pressure correction unit (508) which corrects the pressure of the second gas to be measured in the cell on the basis of a pressure difference; and a second measuring unit (510) which measures a concentration ratio of two types of component gases of the first gas to be measured and the second gas to be measured after being corrected by the pressure correction unit.

Description

Measuring device and measuring method

The present technology relates to a measuring device and a measuring method for measuring a concentration ratio of two kinds of component gases of a first gas to be measured and a second gas to be measured.

測定 Conventionally, in the medical field, measuring devices that use infrared detectors for diagnosing diseases have been developed. The measuring device diagnoses a disease or the like based on a concentration ratio of two types of component gases contained in a gas to be measured (expired gas of the subject) from a living body (a subject). The two component gases have an isotope relationship with each other.

Typically, the measurement device is configured to measure the concentration ratio of two types of component gases contained in the first measured gas before administering the drug to the living body, and the concentration ratio between the two component gases contained in the first measuring gas after administering the drug to the living body. The concentration ratio of the two kinds of component gases contained is measured. The measuring device causes the first gas to be measured to be accommodated in the cell and the second gas to be measured to be accommodated in the cell. The measuring device is configured to determine a concentration ratio between two kinds of component gases contained in the first gas to be measured contained in the cell and a concentration ratio of two kinds of component gases contained in the second gas to be measured contained in the cell. Based on this, a diagnosis of a disease or the like is made.

For example, Patent Literature 1 proposes a technique in which a measuring device pumps a gas to be measured into a cell and pressurizes the gas to be measured in the cell in order to improve the accuracy of measuring the concentration ratio of the component gas. I have. Further, in Patent Document 2, in order to improve the accuracy of measuring the concentration ratio of the component gas, the measuring device sets the concentration of the component gas to be the same in the first gas to be measured and the second gas to be measured in the cell. As such, it has been proposed to dilute the measured gas having a higher component gas concentration with the outside air.

JP-A-2002-98629 JP-A-10-197444

As described above, a measuring device that improves the accuracy of the measurement of the concentration ratio of the component gas has been proposed. However, in recent years, as the technology of medical equipment has advanced, it is desired to further improve the accuracy of the measurement of the concentration ratio of the component gas. It is rare.

技術 The present technology aims to provide a measuring device and a measuring method that improve the accuracy of measuring the concentration ratio of component gases.

A measuring device according to an aspect of the present invention includes a cell containing a gas to be measured containing two types of component gases having an isotope relationship with each other, and measures the absorbance of transmitted light having a wavelength suitable for the gas to be measured in the cell. A measuring device for measuring the concentrations of the two types of component gases of the gas to be measured in the cell on the basis of the absorbance, wherein the first gas and the second gas to be measured are collected as the gas to be measured. A first measuring unit that measures the concentration of the component gas, and a second measuring unit that measures the concentration of the component gas of the first measured gas and the concentration of the component gas of the second measured gas that are measured by the first measuring unit. A concentration adjusting section for adjusting the concentration of at least one of the component gas of the first measurement gas and the second measurement gas, and a first measurement gas and a second measurement gas which have been adjusted by the concentration adjustment section are accommodated. With a predetermined force in the cell At least one of the first gas to be measured and the second gas to be measured, based on the pressure difference to be applied and the concentration difference between the component gases of the first gas to be measured and the second gas to be measured measured by the first measuring unit. A pressure compensating section for compensating the pressure in the pressurizing section, and a second compensating section for measuring the concentration ratios of the two types of component gases with respect to each of the first gas to be measured and the second gas to be measured after being corrected by the pressure compensating section And two measuring units.

A measuring device according to a different aspect of the present invention includes a cell containing a gas to be measured containing two kinds of component gases having an isotope relationship with each other, and measures the absorbance of transmitted light having a wavelength suitable for the gas to be measured in the cell. A measuring device for measuring the concentrations of the two types of component gases of the gas to be measured in the cell on the basis of the absorbance, wherein the first gas and the second gas to be measured are collected as the gas to be measured. A first measuring unit that measures the concentration of the component gas, and a second measuring unit that measures the concentration of the component gas of the first measured gas and the concentration of the component gas of the second measured gas that are measured by the first measuring unit. A concentration adjusting section for adjusting the concentration of at least one of the component gas of the first measurement gas and the second measurement gas, and a first measurement gas and a second measurement gas which have been adjusted by the concentration adjustment section are accommodated. Predetermined force in a closed cell A pressurizing unit for pressurizing, and a pressure for measuring a pressure value of a gas to be measured having a higher concentration of at least a component gas among the first gas to be measured and the second gas to be measured in the cell pressurized by the pressurizing unit. A measuring unit, based on a pressure difference between the first gas to be measured and the second gas to be measured measured by the pressure measuring unit, at least one of the first gas to be measured and the second gas to be measured; A pressure correction unit for correcting the pressure; and a second measurement unit for measuring the concentration ratio of the two types of component gases with respect to each of the first measured gas and the second measured gas that have been corrected by the pressure correction unit. .

The pressure correction unit is configured such that a higher pressure value of the pressure value of the first measured gas and the pressure value of the second measured gas in the cell pressurized by the pressurizing unit is a lower pressure value. The pressure in the pressurizing section is corrected as described above.

The concentration adjusting unit is configured to set the higher concentration of the concentration of the component gas of the first measured gas and the concentration of the component gas of the second measured gas measured by the first measuring unit to be the lower concentration. , The higher concentration of the gas to be measured is diluted with outside air.

(4) The pressure correcting unit corrects the pressure in the pressurizing unit for one of the first gas to be measured and the second gas to be measured diluted with the outside air in the concentration adjusting unit.

The pressurizing unit further includes a cylinder for pressure-feeding the gas to be measured to the cell, a piston inserted into the cylinder, and a driving unit for driving the piston, and the driving unit is provided in the cell containing the gas to be measured. The piston is driven with a predetermined force so that the pressure value becomes the pressure value when measuring the concentration of the component gas.

The pressure correcting unit corrects the pressure in the pressurizing unit based on the amount of the gas to be measured which is pumped from the cylinder into the cell.

(4) The pressure compensating unit reduces the amount of pumping of one of the first gas to be measured and the second gas to be measured, which has a higher pressure value in the cell pressurized by the pressurizing unit, from the cylinder into the cell.

(4) The pressure compensating unit reduces the amount of pumping in the process of accommodating a predetermined amount of gas to be measured to be pumped into the cell by the pressurizing unit.

The two component gases are ¹² CO ₂ and ¹³ CO ₂ .
A measurement method according to an aspect of the present invention includes a cell containing a gas to be measured containing two types of component gases having an isotope relationship with each other, and measures the absorbance of transmitted light having a wavelength suitable for the gas to be measured in the cell. A measurement method for measuring the concentrations of two types of component gases in the gas to be measured in the cell based on the absorbance, wherein the first gas and the second gas to be measured are collected as the gas to be measured. The step of measuring the concentration of the component gas; and the step of measuring the concentration of the component gas of the first measured gas and the concentration of the component gas of the second measured gas so as to be the same. Adjusting the concentration of at least one component gas of the measurement gas, and pressurizing the adjusted first and second measurement gases with a predetermined force in the accommodated cell. , The measured first Correcting the pressure in at least one pressurizing section of the first gas to be measured and the second gas to be measured based on the concentration difference between the component gases of the constant gas and the second gas to be measured; Measuring the concentration ratio of the two types of component gases to each of the first measured gas and the second measured gas.

A measurement method according to a different aspect of the present invention includes a cell containing a gas to be measured containing two types of component gases having an isotope relationship with each other, and measures the absorbance of transmitted light having a wavelength suitable for the gas to be measured in the cell. A measurement method for measuring the concentrations of two types of component gases in the gas to be measured in the cell based on the absorbance, wherein the first gas and the second gas to be measured are collected as the gas to be measured. The step of measuring the concentration of the component gas; and the step of measuring the concentration of the component gas of the first measured gas and the concentration of the component gas of the second measured gas so as to be the same. Adjusting the concentration of at least one component gas of the measurement gas, and pressurizing the adjusted first and second measurement gases with a predetermined force in the accommodated cell. , Pressurized Measuring the pressure value of each of the first measured gas and the second measured gas within the first gas, and the first measured gas based on the measured pressure difference between the first measured gas and the second measured gas. Correcting the pressure in at least one of the pressurizing units of the first and second measured gases, and the concentration ratio of the two types of component gases to the corrected first and second measured gases, respectively. Measuring.

According to an embodiment of the present invention, it is possible to provide a measuring device and a measuring method for improving the accuracy of measuring the concentration ratio of component gases.

It is a schematic diagram for explaining the composition of the measuring device concerning this embodiment. FIG. 2 is a block diagram illustrating a configuration of an arithmetic circuit according to the embodiment. It is a schematic diagram for explaining the composition of the gas injector concerning this embodiment. FIG. 3 is a block diagram for explaining a functional configuration example of an arithmetic circuit according to the embodiment. It is a flowchart of the measuring device concerning this embodiment. It is a diagram for explaining the like CO ₂ transition of the measuring apparatus according to the present embodiment. It is a figure for explaining the 1st correspondence table. It is a figure for explaining the 2nd correspondence table. It is a figure for explaining main processing of a measuring device concerning this embodiment. It is a figure for explaining the 3rd correspondence table. FIG. 9 is a diagram for explaining driving of a piston according to another embodiment. FIG. 9 is a diagram for describing main processing of a measurement device according to another embodiment.

[First Embodiment]
Embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding portions have the same reference characters allotted, and description thereof will not be repeated.

(Application example)
The measuring device according to the present embodiment, after administering a drug containing an isotope to a living body, measures the change in the concentration ratio of the isotope by the light absorption characteristics of the isotope, obtains the metabolic rate of the living body, and obtains the disease. An apparatus used for diagnosis will be described as an example. Specifically, a measurement device used for diagnosing whether or not Helicobacter pylori (HP), which is said to cause gastric ulcer and gastritis, is present in the stomach of the subject will be described.

Various methods have been proposed as a method for diagnosing whether or not HP exists in a subject. In the measuring device according to the present embodiment, the urea marked with the isotope ¹³ C administered to the subject is decomposed by utilizing the property of HP to decompose urea into carbon dioxide and ammonia by the strong urease activity. Diagnosis of the presence or absence of HP is made from the change in the concentration ratio of ¹³ CO ₂ obtained.

Here, carbon has a mass number of 12 and isotopes with mass numbers of 13 and 14 in addition to those having a mass number of 12. Among these isotopes, an isotope ¹³ C having a mass number of 13 has no radioactivity. It is easy to handle because it exists stably. Therefore, the urea to be administered to the subject is marked with the isotope ¹³ C, and when HP is present in the stomach of the subject, the urea is decomposed into ¹³ CO ₂ and ammonia by the HP. Since the decomposed ¹³ CO ₂ is contained in and exhaled from the subject's breath, by measuring the concentration ratio of ¹³ CO ₂ contained in the subject's exhalation, the HP can reduce It is possible to make a diagnosis as to whether or not it is present inside.

The concentration ratio between ¹³ CO ₂ and ¹² CO ₂ contained in the air is 1: 100. Therefore, the measuring device according to the present embodiment is required to accurately measure the concentration ratio between ¹³ CO ₂ and ¹² CO ₂ . In the measuring apparatus according to the present embodiment, infrared spectroscopy is used as a method for determining the concentration ratio between ¹³ CO ₂ and ¹² CO _2, and the absorption of ¹³ CO ₂ in one cell and the other cell And _two short and long cells, which have the same absorption of ¹² CO _{2 at} the same time. The measuring device irradiates each cell with infrared light of a wavelength suitable for each analysis, measures the amount of transmitted light (the amount of transmitted light), and includes the concentration ratio in air in the breath of the subject. The change in concentration ratio is required. The method of obtaining the concentration ratio between ¹³ CO ₂ and ¹² CO ₂ is disclosed in Japanese Patent Publication No. Sho 61-42219 and Japanese Patent Publication No. Sho 61-42220.

Hereinafter, the case where the concentration ratio of ¹³ CO _{2 in} exhaled breath is spectroscopically measured after administering the urea diagnostic agent marked with the isotope ¹³ C to the subject will be described in detail with reference to the drawings. First, the breath of the subject before administration of the urea diagnostic agent is collected in a breath bag as a first measurement gas (also referred to as a base gas). Thereafter, the urea diagnostic agent is orally administered to the subject, and after about 20 minutes, the breath of the subject is collected in a breath bag as a second gas to be measured (also referred to as a sample gas).

The exhalation bag of the first gas to be measured and the exhalation bag of the second gas to be measured are set on predetermined nozzles of the measuring device, respectively, and the concentration ratio between ¹³ CO ₂ and ¹² CO ₂ is measured.

(measuring device)
FIG. 1 is a schematic diagram for explaining the configuration of the measuring device 100 according to the first embodiment. In the measuring apparatus 100, the exhalation bag B of the first measured gas and the exhalation bag S of the second measured gas are set in the nozzles N1 and N2, respectively. The nozzle N1 is connected to a filter F1 and a valve (for example, an electromagnetic valve) V2 through a pipe (for example, a metal pipe). The filter F1 is a filter for removing foreign substances other than the first gas to be measured contained in the breath bag B. The nozzle N2 is connected to the filter F2 and the valve V3 through a pipe. The valve V2 and the valve V3 are connected to the gas injector 21 through one pipe. The filter F2 is a filter for removing foreign substances other than the first gas to be measured contained in the breath bag S.

パイプ Valves V1, V4, and V5 are connected to the pipe connected to the gas injector 21. The valve V1 is connected to the filter F5 and the reference gas supply unit 30 through a pipe. The reference gas supply unit 30 includes a carbon dioxide gas absorption unit that uses, for example, soda lime (a mixture of sodium hydroxide and calcium hydroxide) as a carbon dioxide gas absorbent. Therefore, the reference gas supply unit 30 can supply the gas injector 21 with a reference gas that has absorbed carbon dioxide from air taken in from the outside. Note that the filter F5 is a dustproof filter that removes foreign matter from the reference gas supplied to the gas injector 21.

The valve V4 is connected to the filter F4 and the cell 11 through a pipe. The valve V5 is connected to the filter F3 through a pipe. The filter F3 is provided at an intake port for taking in air from the outside, and is a filter for removing foreign matter from the taken-in air. The filter F4 is a dry filter that removes moisture from the reference gas, the second measured gas, and the second measured gas supplied to the gas injector 21.

The other end of the valve V4 is connected to a first sample cell 11a for measuring the absorption of ¹² CO ₂ . The first sample cell 11a is a short cell for measuring the absorption of ¹² CO _{2 in} one of the cells 11. The cell 11 further includes a long second sample cell 11b and an auxiliary cell 11c for measuring the absorption of ¹³ CO ₂ . The first sample cell 11a and the second sample cell 11b communicate with each other, and the gas guided to the first sample cell 11a enters the second sample cell 11b as it is and is exhausted through the valve V6. The auxiliary cell 11c is filled with a reference gas that does not absorb infrared rays and is sealed. Note that the auxiliary cell 11c may not always be filled with the reference gas and sealed, but may guide the reference gas from the reference gas supply unit 30 and constantly flow the same at a constant flow rate.

容量 The capacity of the first sample cell 11a is about 0.1 ml, and the capacity of the second sample cell 11b is about 3.7 ml. A sapphire transmission window for transmitting infrared light is provided on an end face of the cell 11. The cell 11 is connected to a pressure gauge 31 through a pipe. The pressure gauge 31 can measure the pressure of the gas introduced into the cell 11 by the gas injector 21. Further, a cylinder 21 b described later is connected to the pressure gauge 33. The pressure gauge 33 can measure the pressure of the gas introduced into the cylinder 21b.

光源 On one end face side of the cell 11, light source devices L1 and L2 that emit infrared light are provided. The light source devices L1 and L2 are provided with two waveguides (not shown) for irradiating infrared rays. The method of generating infrared light by the light source devices L1 and L2 may be any method, for example, a ceramic heater (surface temperature of 450 ° C.) or the like can be used. An optical chopper 22 is provided between the light source devices L1 and L2 and the cell 11 to block and pass infrared light at a constant period. The optical chopper 22 can cause the cell 11 to emit infrared light at a constant cycle (for example, 600 Hz) by being rotated by the motor 22a. That is, the optical chopper 22 is an optical modulator that modulates the intensity of the infrared light emitted from the light source devices L1 and L2 into a sine wave shape.

赤外 The infrared light emitted from the light source device L1 passes through the second sample cell 11b, and the amount of light is detected by the first detection element 25a. A wavelength filter 24a is provided between the second sample cell 11b and the first detection element 25a. The amount of infrared light emitted from the light source device L2 passes through the first sample cell 11a and the auxiliary cell 11c, and the amount of light is detected by the second detection element 25b. A wavelength filter 24b is provided between the first sample cell 11a and the auxiliary cell 11c and the second detection element 25b.

The wavelength filter 24a is designed to pass infrared light having a wavelength of about 4412 nm to measure absorption of ¹³ CO ₂ , and the wavelength filter 24b is designed to pass infrared light having a wavelength of about 4280 nm to measure absorption of ¹² CO _2. Have been. The first detection element 25a and the second detection element 25b are elements that detect the amount of infrared light.

The entire first detection element 25a and second detection element 25b are maintained at a constant temperature by a heater and a Peltier element 27. Further,

fans

28 and 29 for ventilating the air inside the measuring device 100 are provided. Further, the measuring apparatus 100 includes a drive circuit 50 that drives the valves V1 to V6, the gas injector 21, and the like.

The valve V1 is a valve that is opened when the reference gas is taken into the cylinder 21b. The valve V2 is a valve that is opened when the first measured gas is taken into the cylinder 21b from the expiration bag B of the first measured gas. The valve V3 is a valve that is opened when the second measured gas is taken into the cylinder 21b from the second measured gas expiration bag S. The valve V4 is a valve that is opened when the gas (measured gas, reference gas) in the cylinder 21b is pumped to the cell 11. The valve V5 is a valve that is opened when the gas to be measured is discharged to the outside before the gas to be measured is pumped into the cell 11 (before the gas to be measured is stored in the cell 11). The valve V6 is a valve that is opened when the measured gas (the measured gas that has passed through the cell 11) is discharged to the outside when the measured gas is pumped into the cell 11.

(Drive circuit)
FIG. 2 is a block diagram for explaining the configuration of the drive circuit 50 according to the first embodiment. 2, drive circuit 50 includes a microprocessor 51, a chipset 52, a main memory 54, a non-volatile memory 56, a system timer 58, a display controller 60, and an I / O controller 70. Including. The chipset 52 and other components are respectively connected via various buses.

The microprocessor 51 and the chip set 52 are typically configured according to a general-purpose computer architecture. That is, the microprocessor 51 interprets and executes instruction codes sequentially supplied from the chipset 52 according to the internal clock. The chipset 52 exchanges internal data with various connected components and generates an instruction code required for the microprocessor 51. Further, the chipset 52 has a function of caching data and the like obtained as a result of execution of arithmetic processing in the microprocessor 51.

The drive circuit 50 has a main memory 54 and a nonvolatile memory 56 as storage means.

The main memory 54 is a volatile storage area (RAM), and holds various programs to be executed by the microprocessor 51 after the power supply to the drive circuit 50 is turned on. The main memory 54 is also used as a working memory when the microprocessor 51 executes various programs. As such a main memory 54, a device such as a DRAM (Dynamic Random Access Memory) or an SRAM (Static Random Access Memory) is used.

On the other hand, the non-volatile memory 56 non-volatilely stores data such as a real-time OS (Operating System), a system program of the measuring apparatus 100, a user program, a calculation program, and setting parameters. These programs and data are copied to the main memory 54 so that the microprocessor 51 can access them as necessary. As such a nonvolatile memory 56, a semiconductor memory such as a flash memory can be used. Alternatively, a magnetic recording medium such as a hard disk drive or an optical recording medium such as a DVD-RAM (Digital Versatile Disk Random Access Memory) can be used.

(4) The system timer 58 generates an interrupt signal at regular intervals and provides it to the microprocessor 51. Typically, an interrupt signal is generated at a plurality of different cycles depending on hardware specifications. However, an interrupt signal is generated at an arbitrary cycle by an OS (Operating System) or a BIOS (Basic Input Output System). It can also be set to generate a signal.

The display controller 60 is connected to the display unit provided in the measuring device 100 via the connection unit 68, and controls the display unit. The display controller 60 includes a memory operation circuit 62, a display operation circuit 64, and a buffer memory 66.

The buffer memory 66 functions as a transmission buffer for display data output to the display unit via the display controller 60 and a reception buffer for input data input from the display unit (for example, a touch panel).

The memory operation circuit 62 transfers output data from the main memory 54 to the buffer memory 66, and transfers input data from the buffer memory 66 to the main memory 54.

The display operation circuit 64 performs a process of transmitting display data of the buffer memory 66 and a process of receiving input data and storing the received data in the buffer memory 66 with a display unit connected thereto.

The I / O controller 70 is connected to a control device such as valves V1 to V6 and a pulse motor 21f provided in the measurement device 100 via a connection unit 78, and outputs control signals to the valves V1 to V6 and the pulse motor 21f. It controls the input of digital signals from the pressure gauge 31 and the like. The I / O controller 70 includes a memory operation circuit 72, a signal operation circuit 74, and a buffer memory 76.

The buffer memory 76 functions as a transmission buffer for control signals output to the valves V1 to V6 and the pulse motor 21f via the I / O controller 70, and as a reception buffer for digital signals input from the pressure gauge 31.

The memory operation circuit 72 transfers a control signal from the main memory 54 to the buffer memory 76 and transfers a digital signal from the buffer memory 76 to the main memory 54.

The signal operation circuit 74 performs a process of transmitting a control signal of the buffer memory 76 and a digital signal to and from a control device such as the valves V1 to V6 and the pulse motor 21f connected to the I / O controller 70 and receives the digital signal. Then, a process of storing the data in the file 76 is performed.

(About gas injector)
FIG. 3 is a diagram showing a gas injector 21 for quantitatively pumping the gas to be measured. FIG. 3A is a plan view of the gas injector 21, and FIG. 3B is a front view of the gas injector 21. In the gas injector 21, a base 21a, a cylinder 21b, and a piston 21c are shown. And The piston 21c is inserted inside the cylinder 21b. The cylinder 21b is disposed on the base 21a.

Furthermore, the gas injector 21 includes a nut 21d, a screw 21e, and a pulse motor 21f. The nut 21d, the screw 21e, and the pulse motor 21f are arranged below the base 21a. The nut 21d is connected to the piston 21c and is movable in the X1 direction or the X2 direction. The screw 21e is engaged with the nut 21d. Further, the pulse motor 21f rotates the feed screw 21e.

The pulse motor 21f is driven forward or reverse by the drive circuit 50 (see FIG. 4). When the screw 21e is rotated by the rotation of the pulse motor 21f, the nut 21d and the piston 21c move integrally in the X1 direction or the X2 direction according to the rotation direction. Thus, the drive circuit 50 drives the piston 21c. The drive circuit 50 performs a process of pumping the gas to be measured into the cylinder 21b to the first sample cell 11a and the second sample cell 11b in accordance with the driving of the piston 21c and the opening and closing of each of the valves V1 to V6. For example, a process of introducing a gas to be measured can be performed.

Also, as shown in FIG. 11 described later, the initial position of the piston 21c is referred to as “initial position H”. In addition, a position that is moved by driving the piston 21c by the maximum amount in the X2 direction is referred to as a “maximum position M”. The measurement device 100 returns the piston 21c to the initial position H when performing a process of pumping the gas to be measured to the cell. Further, the X2 direction is also referred to as a “pressure feeding direction”.

When the process using the piston 21c is completed, the drive circuit 50 returns the piston 21c to the initial position H. In the present embodiment, when the drive circuit 50 returns the piston 21c to the initial position H, when the piston 21c is located on the X2 direction side of the initial position H, the piston 21c is located on the X1 direction side of the initial position H. It is once moved to the back position B (see FIG. 11A). Thereafter, the drive circuit 50 returns the piston 21c to the X2 direction side, and returns the position of the piston 21c to the initial position H.

For example, in a mechanical element such as the screw 21e and the nut 21d, a backlash may occur at a point A shown in FIG. If the drive circuit 50 does not execute the “process of temporarily moving to the back position B”, the backlash remains generated. When the drive circuit 50 attempts to move the piston 21c to the X2 side from the initial position H in a state where the backlash is still generated, the driving amount of the piston 21c is absorbed by the generated backlash. . Then, the drive amount of the piston 21c is different from the drive amount intended by the developer or the like when the measuring device 100 is designed.

Therefore, in the present embodiment, when returning the position of the piston 21c to the initial position H, after performing the process of temporarily moving the piston 21c to the back position B (the process shown in FIG. 11A), the piston 21c is moved in the X2 direction. Then, the process of returning to the side (the process shown in FIG. 11B) is executed. Thereby, the measuring device 100 can return the piston 21c to the initial position H while eliminating the backlash that has occurred. Such processing is called "backlash elimination processing". In addition, even if it is another process, when returning the piston 21c to the initial position H, the measuring apparatus 100 commonly performs the backlash elimination process. Other parts in FIG. 11 will be described later.

The initial position H, the back position B, and the maximum position M are predetermined positions. At least one of these positions can be changed by a user or the like. The moving speed of the piston 21c is also predetermined, and the moving speed can be changed by a user or the like.

(Main processing of the measuring device)
FIG. 4 is a diagram showing main functions of the drive circuit 50. The drive circuit 50 includes functions of a first measuring unit 502, a density adjusting unit 504, a pressurizing control unit 506, a pressure correcting unit 508, a second measuring unit 510, and a pressure measuring unit 512. First measuring unit 502, the preliminary measurement of the first measurement gas and the second measurement gas, to measure the concentration of CO ₂ in the CO ₂ concentration and the first measurement gas in the first measurement gas. The concentration adjuster 504 controls the concentration of CO ₂ of the first gas to be measured measured by the first measuring unit 502 to be the same as the concentration of CO ₂ of the _second gas to be measured measured by the first measuring unit 502. Then, take in the outside air. The pressurization control unit 506 pressurizes the gas (measured gas, reference gas) in the cell 11 so that the pressure of the gas is set as a reference pressure. The pressure correction unit 508 pressurizes at least one of the first measured gas and the second measured gas based on the pressure difference between the first measured gas and the second measured gas measured by the pressure measuring unit 512. The pressure in the control unit 506 (the pressure of the gas in the cell 11) is corrected.

FIG. 5 is a flowchart showing main processing of the drive circuit 50. When FIG. 5 is roughly described, the drive circuit 50 executes the pre-measurement and the main measurement after the execution of the pre-measurement. The drive circuit 50 is referred to as reference gas measurement (step S1 in FIG. 5), preliminary measurement of the first measured gas (step S2), reference gas measurement (step S3), and preliminary measurement of the second measured gas (step S4). Perform each measurement in sequence as a pre-measurement.

(4) After the completion of the preliminary measurement, the drive circuit 50 executes the processing of steps S6 to S28 as the main measurement.

First, in step S1, the drive circuit 50 performs reference measurement. Here, reference gas measurement will be described. The drive circuit 50 cleans the gas flow path and the cell 11 by flowing a clean reference gas through the gas flow path and the cell 11, and measures the reference light amount. Typically, the drive circuit 50 opens the valve V1, closes the other valves, and moves the piston 21c in the X1 direction. Thereby, the drive circuit 50 takes in the reference gas into the cylinder 21b. Thereafter, the drive circuit 50 opens the valve V4, closes the other valves, and moves the piston 21c in the X2 direction, thereby sending the reference gas in the cylinder 21b to the cell 11 by pressure. This reference gas cleans the first sample cell 11a and the second sample cell 11b.

In the present embodiment, the reference measurement process (such as the operation of the piston 21c) in step S1 is the same as the reference measurement in steps S3, S7, and S13 described below. Further, the processing of step S8, step S9, and step S10 (such as the operation of the piston 21c) is the same as the processing of step S18, step S19, and step S20.

Next, in step S2, the first measuring unit 502 measures the concentration of the component gas of the first measured gas by performing a preliminary measurement of the first measured gas. In the present embodiment, in the preliminary measurement, the concentration of ¹² CO ₂ is measured as a component gas of the first gas to be measured.

Typically, the first measuring unit 502 opens the valve V2, closes the other valves, and moves the piston 21c in the X1 direction, so that the first gas to be measured is 21b. Thereafter, the first measuring unit 502 opens the valve V4, closes the other valves, and moves the piston 21c in the X2 direction, thereby pumping the first gas to be measured in the cylinder 21b to the cell 11. . The first measuring unit 502 measures the light quantity of the first gas to be measured contained in the cell 11 by the first detecting element 25a, and measures the CO ₂ concentration using the calibration curve (described later) based on the absorbance. The first measurement unit 502 stores the CO ₂ concentration of the first gas to be measured measured in step S2 in a predetermined storage area (for example, the RAM of the main memory 54).

In addition, in each reference measurement, the drive circuit 50 measures the light amount of the reference gas without using the calibration curve. As a modification, the drive circuit 50 may measure the light amount of the reference gas using the calibration curve in each reference measurement.

Next, in step S3, the drive circuit 50 discharges the first gas to be measured and executes the reference measurement. Next, in step S4, the first measuring unit 502 measures the concentration of the component gas of the second measured gas by performing the preliminary measurement of the second measured gas.

Typically, the first measuring unit 502 opens the valve V3, closes the other valves, and moves the piston 21c in the X1 direction, so that the second gas to be measured is cylinderized by the gas injector 21. 21b. Thereafter, the first measuring unit 502 opens the valve V4, closes the other valves, and moves the piston 21c in the X2 direction, thereby pumping the second gas to be measured in the cylinder 21b to the cell 11. . The first measuring section 502 measures the light quantity of the second gas to be measured stored in the cell 11 by the first detecting element 25a, and measures the CO ₂ concentration using the calibration curve based on the absorbance. The drive circuit 50 stores the CO ₂ concentration of the _second gas to be measured measured in step S4 in a predetermined storage area.

Next, in step S6, the drive circuit 50 compares the concentration of ¹² CO ₂ of the first measured gas with the concentration of ¹² CO ₂ of the second measured gas. In the example of FIG. 5, the drive circuit 50, a direction of ¹² CO ₂ concentration of the second gas to be measured, was determined to be higher than the concentration of ¹² CO ₂ in the first measurement gas.

Steps S7 to S12 described below are processing for the first gas to be measured for which the concentration of ¹² CO ₂ is determined to be low. Steps S13 to S24 are processing for the second gas to be measured for which it has been determined that the concentration of ¹² CO ₂ is high.

In step S7, the drive circuit 50 discharges the second gas to be measured and executes the reference measurement. The drive circuit 50 measures the amount of light with the

respective detection elements

25a and 25b while the reference gas is stored in the cell 11. The drive circuit 50 stores the light amount ¹² R1 obtained by the first detecting element 25a and the light amount ¹³ R1 obtained by the second detecting element 25b in a predetermined storage area.

Next, in step S8, the drive circuit 50 executes a process of pumping the first gas to be measured. Typically, the drive circuit 50 takes in the first measured gas from the breath bag B into the cylinder 21b by moving the piston 21c in the X1 direction. The intake amount of the first gas to be measured is a predetermined amount, and is assumed to be Vm ³ in the present embodiment. In step S8, the pressure measuring unit 512 measures the pressure P1 of the first gas to be measured in the cylinder 21b. Typically, the pressure measurement unit 512 acquires the pressure value P1 measured by the pressure gauge 33. The measured pressure of the first gas to be measured is stored in a predetermined area.

Then, the drive circuit 50 pumps the first gas to be measured in the cylinder 21 b into the cell 11. The drive circuit 50 typically opens the valve V4 and the valve V6 and moves the piston 21c in the X2 direction in a state where the other valves are closed, so that the first measured gas in the cell 11 is moved. Pump.

Next, in step S9, the pressurization control unit 506 pressurizes the first gas to be measured in the accommodated cell 11 with a predetermined force. Here, the “predetermined force” is typically a pressure corresponding to a calibration curve. This force is also called “reference pressure”. In other words, the "predetermined force" is typically a force such that the pressure value in the cell 11 containing the gas to be measured becomes the pressure value when measuring the concentration of the component gas. The reference pressure is, for example, 0.2 megapascal (Mpa).

Typically, the pressurization control unit 506 opens the valve V4 and moves the piston 21c in the X2 direction with the other valves including the valve V6 closed, so that the first measured object in the cell 11 is Pressurize the gas.

By the way, the pressure of the outside air may be different depending on the measuring place of the measuring device 100. For example, the pressure of the outside air is different between the case where the measurement location of the measurement device 100 is at a low altitude and the case where the measurement location of the measurement device 100 is at an altitude. As described above, even when the pressure of the outside air is different, the pressurization control unit 506 of the present embodiment has the reference pressure unit that can use the pressure in the cell 11 as the reference pressure. As a method of adjusting the pressure in the cell 11 to the reference pressure, a method of changing the driving amount of the piston 21c according to the pressure of the outside air, or a method of changing the position of the piston 21c to be moved from the valve V6 according to the pressure of the outside air There is a method of changing the amount of gas to be discharged. Hereinafter, a method of changing the driving amount of the piston 21c will be described.

The pressure gauge 33 measures the pressure in the cylinder 21b, and estimates the outside air pressure from the pressure in the cylinder 21b using a predetermined conversion formula. FIG. 7 is a diagram illustrating an example of the first correspondence table. In the example of FIG. 7, the estimated outside air pressure OP1 is associated with the first driving distance L1, and the outside air pressure OP2 is associated with the first driving distance L2. FIG. 7 shows a three-point reader, and indicates that the three-point reader omits associating another external pressure with the first driving distance. Note that, as a modification, the pressure control unit 506 may use the first correspondence expression instead of the correspondence table in FIG. The first correspondence equation is an equation for calculating the first driving distance T when the external pressure OP is input.

The pressurization control unit 506 acquires the first driving distance corresponding to the estimated outside air pressure with reference to the correspondence table shown in FIG. When the piston 21c is at the initial position H, the pressurization control unit 506 opens the valves V4 and V6, closes the other valves, and starts moving the piston 21c. When determining that the first drive distance has elapsed since the start of the movement of the piston 21c, the pressurization control unit 506 closes the valve V6 while maintaining the valve V4 open. Thereafter, the pressurization control unit 506 drives the piston 21c to the maximum position M.

As described above, in step S9, the pressurization control unit 506 pressurizes the first measured gas in the cell 11 so that the first measured gas in the cell 11 has the reference pressure value. The method of pressurization is not limited to this, and another method may be used. The details of this pressurizing method are disclosed in, for example, “Japanese Patent Application Laid-Open No. 2002-98629”.

Next, in step S12, the second measuring unit 510 measures the light amount of the first gas to be measured. The second measuring unit 510 measures the light amount by the

respective detection elements

25a and 25b in the pressurized state in step S9. The second measuring unit 510, the amount of light ¹² B obtained in the first detection element 25a, the amount of light ¹³ B obtained by the second detection element 25b, is stored in a predetermined storage area.

Next, in step S13, the drive circuit 50 discharges the first gas to be measured and performs reference measurement. The drive circuit 50 measures the amount of light with the

respective detection elements

25a and 25b while the reference gas is stored in the cell 11. The drive circuit 50 stores the light amount ¹² R2 obtained by the first detecting element 25a and the light amount ¹³ R2 obtained by the second detecting element 25b in a predetermined storage area.

Next, in step S14, the concentration adjusting unit 504 makes the CO ₂ concentration of the first measured gas measured in step S2 equal to the CO ₂ concentration of the second measured gas measured in step S4. So, take in outside air. Here, the outside air refers to “air outside the measuring apparatus 100 and air that has passed through the reference gas supply unit 30”. That is, “outside air” is a gas that does not contain CO ₂ (component gas).

In the present embodiment, the concentration of CO ₂ is higher in the _second measured gas than in the first measured gas. Therefore, the concentration adjusting unit 504 takes in outside air for the second gas to be measured. On the other hand, the concentration adjusting unit 504 does not take in outside air for the first gas to be measured.

For example, as shown in FIG. 6 described later, a 4% CO ₂ concentration in the step S2, when the concentration of CO ₂ in step S4 is 2%, the pressurization control unit 506, V / 2 m ³ of the second gas to be measured (gas having a high concentration of CO ₂ ) is taken into the cell 11 from the expiration bag S, and thereafter, outside air of V / 2 m ³ is taken into the cylinder 21 b from the reference gas supply unit 30. . V is the amount of the first gas to be measured as described above.

Next, in step S16, the drive circuit 50 executes the reciprocating drive of the piston 21c in the X1 direction and the X2 direction with all the valves closed. Accordingly, the concentration adjusting unit 504 in the cylinder 21b, it is possible to mix the second and the measurement gas in V / 2m ^3, and an outside air V / 2m ^3. In step S16, the drive circuit 50 pressurizes the mixed second gas to be measured by the reciprocating motion in a state where all the valves are closed.

The concentration adjusting unit 504 controls the first measurement gas and the second measurement gas such that the concentration of the component gas of the first measurement gas and the concentration of the component gas of the second measurement gas measured by the first measurement unit 502 are the same. The concentration of at least one of the two component gases is adjusted. Further, in the present embodiment, the concentration adjusting unit 504 determines the higher one of the concentration of the component gas of the first measured gas and the concentration of the component gas of the second measured gas measured by the first measuring unit 502 (FIG. 5). In the example, the measurement gas having the higher concentration is diluted with the outside air so that the concentration of the second measurement gas is lower (the first measurement gas in the example of FIG. 5). The details of the diluting method are disclosed in, for example, "Japanese Patent Application Laid-Open No. 10-197444".

If the concentration of CO ₂ in the first gas to be measured is different from the concentration of CO _{2 in} the _second gas to be measured, an error may occur in the measurement result of the concentration ratio between ¹³ CO ₂ and ¹² CO _2. Is known. The measurement apparatus 100 can eliminate such an error by making the first measurement gas and the second measurement gas have the same CO ₂ concentration.

Next, in step S17, the pressure measuring unit 512 measures the pressure value P2 of the second gas to be measured. Typically, the pressure measurement unit 512 acquires the pressure value P2 measured by the pressure gauge 33. The measured pressure value P2 of the second gas to be measured is stored in a predetermined area. Note that the pressure value P2> the pressure value P1.

(4) In step S17, the pressure correction unit 508 corrects the pressure of the second gas to be measured. The pressure correction unit 508 determines the first pressure value of the first measured gas in the cylinder 21b (see the description of Step S8) and the second pressure value P2 of the second measured gas in the cylinder 21b based on the pressure difference. The pressure in at least one of the first measured gas and the second measured gas in the pressurization control unit 506 (in the present embodiment, the pressure in the pressurization control unit 506 of the second measured gas having a high pressure value) is corrected. I do. Typically, the pressure correction unit 508 performs correction so as to reduce the pressure value of the second gas to be measured. Typically, the pressure correction unit 508 sets the piston 21c to X2 while the valve V4 and the valve V6 are opened and the other valves are closed in a state where the second gas to be measured is accommodated in the cylinder 21b. Drive in the direction. Then, the pressure correction unit 508 can discharge the second gas to be measured in the cylinder 21b to the outside through the route of the valve V4, the cell 11, and the valve V6. Accordingly, the pressure correction unit 508 corrects the pressure value of the second measured gas so as to decrease according to the value based on the pressure value P1 and the pressure value P2. The pressure correction processing in step S17 will be described later with reference to FIG.

Next, in step S18, the pressurization control unit 506 executes a pressure feeding process of the diluted second gas to be measured. Next, in step S19, the pressurization control unit 506 pressurizes the second gas to be measured in the accommodated cell 11 with a predetermined force. In the present embodiment, pressure is applied twice in the dilution process in step S16 and the pressurization process in step S19. The processing in step S18 and the processing in step S19 (the pressurization rate, the driving amount of the piston 21c, etc.) are the same as those in steps S8 and S9. Further, the processing of steps S8 and S9 is executed by one movement of the piston 21c at the initial position in the X2 direction. Further, the pressure correction processing in step S17 and the processing in steps S18 and S19 are executed by one movement in the direction of the piston 21cX2 existing at the initial position.

Next, in step S24, the second measuring unit 510 measures the light amount of the second gas to be measured. The measuring device 100 measures the light amount by the

respective detection elements

25a and 25b in the pressurized state in step S19. The measuring device 100 stores the light quantity ¹² S obtained by the first detection element 25 a and the light quantity ¹³ S obtained by the second detection element 25 b in a predetermined storage area.

Next, in step S26, the drive circuit 50 executes the reference measurement while discharging the first gas to be measured. The drive circuit 50 measures the amount of light with the

respective detection elements

25a and 25b while the reference gas is stored in the cell 11. The drive circuit 50 stores the light quantity ¹² R3 obtained by the first detection element 25a and the light quantity ¹³ R3 obtained by the second detection element 25b in a predetermined storage area.

Next, in step S28, the second measuring unit 510 determines the concentration ratios of the two types of component gases with respect to each of the first measured gas and the second measured gas that have been corrected by the pressure correcting unit 508 in step S22. Is measured.

Typically, the second measuring unit 510, the following equation (1), (2), the 1 ¹² CO ₂ absorbance ¹² Abs of the measurement gas ^(B), and the 13 CO ₂ absorbance ¹³ Abs ( B).

^{^{12 Abs (B) = - log}} [2 · 12 B / (12 R 1 + 12 R 2)] (1)
^{^{13 Abs (B) = - log}} [2 · 13 B / (13 R 1 + 13 R 2)] (2)
Note ^that the 12 _{R ^1,} and 13 _{R 1,} obtained in step ^S7, and 12 _{R ^2,} and 13 _{R 2,} determined in the step ^S13, and ¹² ^B, and ¹³ B, determined in step S12 .

The second measuring unit 510, the following equation (3), (4), and the second ¹² CO ₂ absorbance ¹² Abs of the measurement gas ^(S), 13 CO ₂ absorbance ¹³ Abs (S) and Ask for.

^{^{12 Abs (S) = - log}} [2 · 12 S / (12 R 2 + 12 R 3)] (3)
^{^{13 Abs (S) = - log}} [2 · 13 S / (13 R 2 + 13 R 3)] (4)
Note ^that the 12 _{R ^3,} A 13 _{R 3,} obtained in step ^S26, and ¹² ^S, and ¹³ S, determined in step S24.

Next, the second measuring unit 510 uses the calibration curve to determine the concentration ratio between ¹² CO ₂ and ¹³ CO ₂ of the first gas to be measured, and ¹² CO ₂ and ¹³ CO _{2 of the} _second gas to be measured. The concentration ratio is determined. The measurement device 100 creates the calibration curve using the measured gas having a known ¹² CO ₂ concentration and the measured gas having a known ¹³ CO ₂ concentration at the above-described reference pressure value. Since the measurement device 100 measures the gas to be measured by pressurizing it to the reference pressure value, the calibration curve also measures the gas to be measured by pressurizing the gas to be measured to the reference pressure value.

To obtain the calibration curve, the drive circuit 50 measures the absorbance of ¹² CO _{2 while} changing the concentration of ¹² CO _{2 in} a range of about 0% to 6%. The driving circuit 50 plots the horizontal axis at ¹² CO ₂ concentration and the vertical axis at ¹² CO ₂ absorbance, and determines a curve for ¹² CO ₂ concentration using the least squares method. Since the curve approximated by the quadratic equation has a relatively small error curve, the calibration curve approximated by the quadratic equation is employed in the present embodiment.

Similarly, the drive circuit 50 measures the absorbance of ¹³ CO _{2 while} changing the ¹³ CO ₂ concentration in a range of about 0% to 0.07%. The drive circuit 50 plots the horizontal axis at ¹³ CO ₂ concentration and the vertical axis at ¹³ CO ₂ absorbance, and determines a curve for ¹³ CO ₂ concentration using the least squares method. Since the curve approximated by the quadratic equation has a relatively small error curve, the calibration curve approximated by the quadratic equation is employed in the present embodiment.

The ¹² CO ₂ concentration in the first measured gas is ¹² Conc (B), the ¹³ CO ₂ concentration in the first measured gas is ¹³ Conc (B), and the ¹² CO ₂ concentration in the second measured gas is ¹² Conc (S). ), And the ¹³ CO ₂ concentration in the second gas to be measured is ¹³ Conc (S).

{Circle around (2)} The second measuring unit 510 calculates the concentration ratio X (B) of the first measured gas and the concentration ratio X (S) of the second measured gas by the following equations (5) and (6), respectively.

X (B) = ¹³ Conc (B) / ¹² Conc (B) (5)
X (S) = ¹³ Conc (S) / ¹² Conc (S) (6)
As a modification, the second measuring section 510 calculates the concentration ratio X (B) of the first measured gas and the concentration ratio X (S) of the second measured gas by the following equations (7) and (8), respectively. ) May be obtained.

^{^{X (B) = 13 Conc (}} B) / [13 Conc (B) + 12 Conc (B)] (7)
^{^{X (S) = 13 Conc (}} S) / [13 Conc (S) + 12 Conc (S)] (8)
This is because the ¹² CO ₂ concentration is much higher than the ¹³ CO ₂ concentration, so that both have substantially the same value.

The second measuring unit 510, and CO ₂ concentration in the first measurement gas, the CO ₂ concentration variation ΔC of the second measurement gas ^13, for example, be calculated by the following equation (9) Good.

ΔC = [concentration ratio of second measured gas X (S) −concentration ratio of first measured gas X (B)] × 1000 / [concentration ratio of first measured gas X (B)] (9)
The unit of the formula (9) is per mille per thousand.

Under the control of the display controller 60, the measuring device 100 may cause the display unit to display the concentration ratio X (B) of the first measured gas and the concentration ratio X (S) of the second measured gas. Good. The measuring device 100 may cause the display unit to display the change ΔC under the control of the display controller 60. Note that the measuring device 100 determines that the HP is highly likely to be present in the stomach of the subject if the obtained ¹³ CO ₂ concentration change Δ ¹³ CO ₂ is 2.5 permil or more, and determines that the HP is positive. I do.

In the preliminary measurement, the measuring device 100 measures the ¹² CO ₂ concentration but does not measure the ¹³ CO ₂ concentration. On the other hand, in this measurement, both the ¹² CO ₂ concentration and the ¹³ CO ₂ concentration are measured. Therefore, the pre-measurement described in steps S2 and S4 requires less processing amount (computation amount) than the main measurement described in step S24. As a modified example, another method may be adopted as a method of performing the preliminary measurement with a smaller amount of calculation than the main measurement. For example, the amount (arithmetic amount) of the arithmetic expression used in the preliminary measurement may be made smaller than the amount (arithmetic amount) of the arithmetic expression used in the main measurement.

(Change of CO _{2 in} each process)
Next, transition of the concentration of CO _{2 in} each step will be described with reference to FIG. In the example of FIG. 6, CO ₂ ^is, 12 CO ₂ and ¹³ CO ₂ and a mixture of, ^or to summarize the 12 CO ₂ and ¹³ CO _2. 6 (a) to 6 (f) show the concentration of CO _{2 in} each step, FIG. 6 (A) shows the first gas to be measured, and FIG. 6 (B) shows the second gas to be measured. Show.

It is assumed that the CO ₂ concentration of the first gas to be measured is measured to be 2% in the pre-measurement step (step S2) of FIG. 6A. Further, it is assumed that the CO ₂ concentration of the _second gas to be measured is measured to be 4% in the preliminary measurement step (step S4) of FIG. 6A.

Next, in the outside air intake step of FIG. 6B, in step S14, the pressurization control unit 506 takes in the outside air for the second gas to be measured. Then, the dilution step of FIG. 6 (c) (step S16), and the concentration adjusting unit 504 in the cylinder 21b, for mixing the second and the measurement gas in V / 2m ^3, and an outside air V / 2m ³ . Thereby, the pressurization control unit 506 can set the CO ₂ concentration of the second measured gas to 2%, which is the same as the first measured gas. Also in the pressurizing step (step S19) of FIG. 6C, the CO ₂ concentration of the second measured gas is maintained at 2%.

Next, in the pressure measuring step (see the description of step S8) in FIG. 6D, the pressure value P1 of the first gas to be measured of the pressure measuring unit 512 in step S10 is measured. The pressure value A in the example of FIG. 6D is a pressure value when the first gas to be measured having the pressure value P1 is sent to the cell 11 by pressure. The pressure value of the first gas to be measured is = 0.2 megapascal). This is based on the fact that the pressurization control unit 506 has performed the pressurization process so that the pressure value of the first measured gas becomes the reference pressure in step S8.

Here, the pressurization control unit 506 applies the same load to both the first measured gas in the cell 11 and the second measured gas in the cell 11 as described in steps S9 and S19. A pressurization process is performed at a pressure ratio. Therefore, the pressure value of the first measured gas in the cell 11 and the pressure value of the second measured gas in the cell 11 should be the same.

However, the pressure value of the second gas to be measured is higher than the pressure value of the first gas to be measured. As shown in the example of FIG. 6D, it is assumed that the pressure value B of the second measured gas of the pressure measurement unit 512 in step S20 is 0.24 megapascal.

The reason why the pressure value of the second measured gas becomes higher than the pressure value of the first measured gas will be described below. The first gas to be measured and the second gas to be measured are exhalation of the subject, and the exhalation humidity is generally 100% or about 100%. Further, the humidity of the gas to be measured in which the outside air is mixed (the second gas to be measured in the example of FIG. 6) decreases. It has been experimentally found that when the humidity of a gas decreases, the pressure value of the gas increases. That is, the pressure value of the second measured gas in which the outside air is mixed is higher than that of the first measured gas. As described above, the pressure value of the second measured gas becomes higher than the pressure value of the first measured gas.

In the example of FIG. 6D, the pressure value P1 and the pressure value P2 are not described.
Next, in the pressure correction step (Step S17) of FIG. 6E, the pressure correction unit 508 determines the pressure difference between the first measured gas and the second measured gas measured by the pressure measuring unit 512. The pressure in at least one of the first measured gas and the second measured gas in the pressurization control unit 506 is corrected.

Typically, the pressure correction unit 508 first calculates a pressure difference ΔP between the pressure value P1 of the first measured gas in the cylinder 21b and the pressure value P2 of the second measured gas in the cylinder 21b. I do. In the example of FIG. 6, the pressure difference ΔP = P1−P2.

In addition, the measuring device 100 stores a second correspondence table in which the second driving distance of the piston (in the pressure correction process) in a state where the valve V6 is opened and the pressure difference ΔP are stored in the storage area. ing. FIG. 8 is a diagram illustrating an example of the second correspondence table. In the example of FIG. 8, the pressure difference ΔP1 is associated with the second drive distance M1, and the pressure difference ΔP2 is associated with the second drive distance M2. FIG. 8 illustrates a three-point reader, and indicates that the three-point reader omits associating another pressure difference ΔP with the second driving distance. As a modification, the pressure correction unit 508 may use the second correspondence expression instead of the correspondence table in FIG. The second correspondence equation is an equation for calculating the second driving distance T when the pressure difference ΔP is input.

The pressure correction unit 508 drives the piston 21c with the second drive distance T (the valve V4 and the valve V6 are opened, based on the calculated pressure difference ΔP using the second correspondence table or the second correspondence expression. Distance). The pressure correction unit 508 drives the piston 21c in the X2 direction from the initial position H with the valve V4 and the valve V6 opened in a state where the second gas to be measured is accommodated in the cylinder 21b. Therefore, while the valve V6 is open, the second gas to be measured is pumped into the cell 11, but is discharged to the outside via the valve V6 as it is. By opening the second drive distance T and the valve V6, the pressure of the second measured gas in the cylinder 21b becomes equal to the pressure of the first measured gas. As a result, in the pressurizing process in step S9 and the pressurizing process in step S19, the pressure value of the first measured gas in the cell 11 and the pressure value of the second measured gas in the cell 11 may be set as the reference pressure value. it can. In the pressure correction process for the second measured gas, the pressure of the second measured gas in the cylinder 21b does not have to be the same as the pressure of the first measured gas in the cylinder 21b. If the pressure values of the first gas to be measured in the cell 11 and the second gas to be measured in the cell 11 can be set as the reference pressure values after the pressurizing process of step S19 and the pressurizing process of step S19, another configuration is used. You may.

As described above, in the second correspondence table or the second correspondence expression, the second drive distance is determined such that the pressure of the measured gas having the higher pressure value matches the pressure of the measured gas having the lower pressure value. Is designed in advance. As a result, the pressure value of the second gas to be measured in the cell 11 and the pressure value of the first gas to be measured in the cell 11 both become the reference pressure value and become the same by the pressurizing step.

Next, in the light quantity measuring step (step S24) of FIG. 6F, the second measuring unit 510 executes the light quantity measurement of the second gas to be measured. That is, in the light quantity measuring step, the light quantity measurement can be performed in a state where the pressure value of the second measured gas in the cell 11 is the same as the pressure value of the first measured gas in the cell 11. Therefore, as a result, the second measurement unit 510 of the measurement apparatus 100 can measure the concentration ratio of the two types of component gases with respect to the second measurement gas that has been corrected by the pressure correction unit 508.

(About cylinder and valve drive)
FIG. 9 is a diagram illustrating the driving of the piston 21c in the pressure correction processing, the pressure feeding processing, and the pressurization processing of each embodiment and the open / closed state of each valve for the second gas to be measured. FIG. 9A is a diagram illustrating the driving of the piston 21c and the open / closed state of each valve in the pressure correction processing, the pressure feeding processing, and the pressurization processing according to the first embodiment. FIGS. 9B, 12A, and 12B will be described in other embodiments (second to fourth embodiments) described later. 9 and 12, the order of the pressure feeding process and the pressurizing process may be reversed for the first gas to be measured and the second gas to be measured, as a modification.

In the pressure correction process of the first embodiment, in a state where the valves V4 and V6 are opened, over the second drive distance M (the distance corresponding to the pressure difference ΔP in FIG. 9A) shown in FIG. The piston 21c is driven from the initial position H in the X2 direction. Then, it is discharged outside via the valve V4, the cell 11, and the valve V6. By this discharge, the measuring apparatus 100 can make the pressure value of the first measured gas equal to the pressure value of the second measured gas. The second drive distance M is a distance obtained from the second correspondence table (see FIG. 8).

Next, in the pressure feeding process of the first embodiment, the drive circuit 50 drives the piston 21c in the X2 direction after the pressure correction process with the valves V4 and V6 opened. The drive amount at this time is the drive amount L described with reference to FIG.

Next, in the pressurization process, the pressurization control unit 506 drives the piston 21c in the X2 direction following the pressure correction process with the valve V6 closed and the valve V4 opened.

FIG. 11 is a diagram for explaining the pressure correction processing, the pressure feeding processing, and the pressure processing. The driving circuit 50 of the present embodiment houses the second measurement gas in the first measurement gas and Vm ³ of Vm ³ into the cylinder 21b. Note that α is a predetermined amount. As shown in FIG. 11A, after the second measurement gas dilution processing (step S16), the pressure correction unit 508 moves the piston 21c to the initial position with the valve V5 closed as backlash elimination processing. It is moved to the back position B which is on the X1 direction side of H. Next, as shown in FIG. 11B, the pressure correction unit 508 opens the valve V5 and moves the piston 21c from the back position B in the X2 direction to the initial position H as backlash elimination processing. Position.

Thereby, as shown by the arrow in FIG. 11B, the second gas to be measured in the cylinder 21b is discharged to the outside via αm ³ and the opened valve V6 together with the backlash elimination processing. Thereafter, as shown in FIG. 11C, the cylinder 21b is continuously driven in the X2 direction even after the backlash elimination process is completed (after the backlash is eliminated) as shown in FIG. Thereby, the pressure feeding process and the pressure process can be executed.

では In the present embodiment, the drive distance M determined in FIG. 8 is the distance from FIG. 11B to FIG. 11C. Thereafter, as shown in FIG. 11D, the pressurization control unit 506 executes the pressure feeding process and the pressurization process with the valve V5 closed.

As a modified example, a measuring device that does not consider backlash, that is, the processing of FIGS. 11A and 11B may not be executed.

(Effects of the measuring device of the present embodiment)
Next, the effects of the measuring apparatus 100 according to the present embodiment will be described.

(1) In the present embodiment, in order to improve the measurement accuracy of the component gases of the first gas to be measured and the second gas to be measured, the second gas to be measured is diluted (step S16) and the first gas to be measured is And pressurizing processing of the second gas to be measured (step S9, step S19). Here, when the dilution process and the pressurization process are performed on the second measured gas, the pressure value of the second measured gas becomes larger than the pressure value of the first measured gas. That is, the pressure value of the second gas to be measured becomes larger than the reference pressure value. Therefore, in the process using the calibration curve for the second measured gas, the pressure value of the second measured gas is different from the reference pressure value associated with the calibration curve. As a result, in the process using the calibration curve, the measurement accuracy of the concentration ratio between ¹² CO ₂ and ¹³ CO _{2 of the} _second gas to be measured decreases.

構成 Alternatively, a configuration using a plurality of calibration curves according to the pressure value of the second gas to be measured is also conceivable. However, when such a configuration is adopted, the process of preparing a plurality of calibration curves in advance increases, and the storage capacity of the plurality of calibration curves also increases.

Therefore, as shown in step S17 and FIG. 6E, the pressure correction unit 508 determines at least one of the first measured gas in the cylinder 21b and the second measured gas in the cylinder 21b. Correct the pressure value of. Preferably, the pressure correction unit 508 performs the first measurement gas and the second measurement gas so that the pressure value of the first measurement gas in the cylinder 21b is equal to the pressure value of the second measurement gas in the cylinder 21b. The pressure value of at least one of the measured gas and the measured gas is corrected. As a result, the pressure correction unit 508 can set the pressure value of the first measured gas in the cell 11 and the pressure value of the second measured gas in the cell 11 to be the same reference pressure value. Therefore, the measuring device 100 improves the accuracy of measuring the concentration ratio of the component gas.

(2) Further, as shown in step S22 and FIG. 6E, the pressure correction unit 508 determines the pressure value P1 of the first measured gas and the pressure value P2 of the second measured gas in the cylinder 21b. The higher pressure value (in this embodiment, the pressure value P2 which is the pressure value of the second measured gas) is the lower pressure value (in this embodiment, the pressure value of the first measured gas). The pressure value (the pressure value in the cylinder 21b) in the pressurization control unit 506 is corrected so as to be the pressure value P1).

For example, a method of increasing the pressure value of the first measured gas to match the pressure value of the second measured gas is also conceivable. However, a measuring apparatus employing this technique requires a calibration curve corresponding to a pressure value larger than the reference pressure value, in addition to the calibration curve corresponding to the reference pressure value, and the data capacity of the calibration curve increases. I will.

Therefore, in the present embodiment, the pressure correction unit 508 reduces the pressure value of the second measured gas so that the pressure value of the second measured gas becomes equal to the pressure value of the first measured gas (reference pressure value). Correct the pressure value. Therefore, the measuring apparatus 100 only needs to hold a calibration curve corresponding to the reference pressure value, and does not need to hold a calibration curve corresponding to a pressure value different from the reference pressure value. Therefore, the measuring device 100 can prevent an increase in the data capacity related to the calibration curve.

(3) In addition, the concentration adjusting unit 504 calculates the concentration of the component gas (CO ₂ ) of the first measured gas measured by the first measuring unit 502 and the component of the second measured gas measured by the first measuring unit 502. The gas to be measured having a higher concentration (in the example of FIG. 6, the second gas to be measured) is diluted with the outside air so that the higher concentration of the gas (CO ₂ ) becomes the lower concentration. (Step S16).

For example, a method of increasing the CO ₂ concentration of the first measured gas to match the CO ₂ concentration of the second measured gas can be considered. However, a measuring device employing this method needs to mix pure CO ₂ (a gas composed of only CO ₂ ) with the first gas to be measured, and requires a device for producing pure CO ₂ , The cost of the measuring device 100 increases.

Therefore, in this embodiment, the concentration adjusting unit 504, using the outside air, second by reducing the CO ₂ concentration in the measurement gas, the CO ₂ concentration in the first measurement gas. Therefore, the CO ₂ concentration of the first gas to be measured and the second gas to be measured can be matched with an inexpensive configuration.

{(4)} The pressure correction unit 508 corrects the pressure value of the second gas to be measured diluted with the outside air. As described above, it has been found that the second measured gas diluted with the outside air has a higher pressure value than the first measured gas. Therefore, the pressure value of the first measured gas and the second measured gas can be determined without executing a process of determining which of the first measured gas and the second measured gas has a higher pressure value. Can be the same as the pressure value.

{(5)} The pressurizing section for increasing the pressure value of the gas to be measured in the cell 11 is constituted by the cylinder 21b, the piston 21c, and the like. Therefore, the measuring device 100 can increase the pressure value of the gas to be measured in the cell 11 with an inexpensive configuration. Further, the drive circuit 50 moves the predetermined movement amount (ie, the reference pressure value) so that the pressure value in the cell 11 containing the gas to be measured becomes the pressure value when measuring the concentration of the component gas (that is, the reference pressure value). The driving amount) drives the piston 21c. The driving is executed commonly for the first measured gas and the second measured gas (see steps S8 and S18). Therefore, compared to a measuring device in which the driving is performed differently for the first gas to be measured and the second gas to be measured, it is possible to reduce the program capacity related to the driving process of the piston 21c.

{(6)} Further, the pressure correction unit 508 corrects the pressure (for example, the pressure in the cylinder 21b) in the pressurization control unit 506 by driving the piston 21c. The piston 21c performs various processes such as taking in the gas to be measured and the outside air. The measurement device 100 corrects the pressure of the second gas to be measured using the piston 21 that performs various processes. Therefore, the number of parts can be reduced as compared with “a measuring device using different components for various processes such as taking in the gas to be measured and the outside air and correcting the pressure of the second gas to be measured”.

(7) As shown in FIG. 11, the pressure correction unit 508 sends the second gas to be measured diluted with the outside air, that is, the second gas to be measured having a higher pressure value in the cell 11, from the cylinder 21b. The pumping amount to be pumped into the cell 11 is reduced based on the pressure difference ΔP. In other words, the pressure correction unit 508 discharges a part of the second measured gas before pressure-feeding the second measured gas into the cell 11 (decreases the pressure value of the second measured gas). .

For example, the pressure value of the first measured gas when accommodated in the cell 11 and the pressure value of the second measured gas when accommodated in the cell 11 are increased by increasing the pumping amount of the first measured gas. Are conceivable. In the case of such a configuration, a large amount of the first gas to be measured is used. Then, an event such as a shortage of the first gas to be measured in the expiration bag may occur. Therefore, the pressure correction unit 508 of the present embodiment discharges a part of the second measured gas before pumping the second measured gas into the cell 11. As a result, the measurement device 100 of the present embodiment can store the pressure value of the first gas to be measured in the case where the gas to be measured is stored in the cell 11 and the gas stored in the cell 11 without occurrence of an event such as a shortage of the gas to be measured. In this case, the pressure value of the second gas to be measured can be appropriately made equal.

(8) In addition, the pressurization control unit 506 of the present embodiment accommodates a predetermined amount of pumped gas (for example, Vm ^{3 in the} present embodiment) to be pumped into the cell 11 in the cylinder 21b. Execute the process. Here, the accommodation process is the process shown in FIGS. 11A and 11B. The predetermined pumping amount is the amount of the gas to be measured contained in the cylinder 21b when the piston 21c is located at the initial position H (Vm ^{3 in the} present embodiment). The measuring device 100 of the present embodiment reduces the amount of pumping in the accommodation process. Therefore, in a series of processes after the backlash elimination process (see FIGS. 11B and 11C), the second gas to be measured in the cylinder 21b can be discharged to the outside. That is, the pressure value of the second measured gas (the pressure value of the second measured gas stored in the cell 11 in the future) can be adjusted (decreased) in the flow of the process for eliminating the backlash. Therefore, the number of processing steps can be reduced as compared with a measuring apparatus in which the processing for eliminating backlash and the processing for adjusting the pressure value of the second measured gas are not a series of processing.

{(9)} In the measuring apparatus 100 of the present embodiment, the valve to be opened (the valve V6 in the present embodiment) can be shared between the pressure correction processing and the pressure feeding processing. Therefore, as compared with a measuring device that opens a different valve in the pressure correction process and the pressure feeding process, the load of the valve control process can be reduced and the wear of the valve can be reduced.

(10) In this measurement, the two types of component gases whose concentration ratios are measured are ¹² CO ₂ and ¹³ CO ₂ . Therefore, the measuring device 100 can diagnose whether or not Helicobacter pylori (HP) exists in the stomach of the subject.

[Second embodiment]
Next, a measuring apparatus 100 according to a second embodiment will be described. The measurement apparatus 100 of the first embodiment has been described as discharging the second gas to be measured in the cylinder 11 via the valve V6. The measuring device 100 of the second embodiment discharges the second gas to be measured in the cylinder 11 via the valve V5. FIG. 9B is a diagram illustrating the driving of the piston 21c and the open / closed state of each valve in the pressure correction processing, the pressure feeding processing, and the pressurization processing according to the second embodiment.

In the second embodiment, as shown in FIG. 9B, in the pressure correction process for the second gas to be measured, the pressure correction unit 508 opens the valve V5 and closes the valves V1 to V4 and the valve V6. In this state, the cylinder 21b is driven in the X2 direction. According to such a configuration, it is possible to discharge from the valve V5 by the pressure correction processing.

っても The measuring device 100 of the second embodiment also has the same effect as the measuring device 100 of the first embodiment.

[Third embodiment]
The measuring device 100 of the first embodiment and the second embodiment measures the pressure difference ΔP between the pressure value of the first gas to be measured in the cylinder 21b and the pressure value of the second gas to be measured in the cylinder 21b. It has been described that the pressure of the second gas to be measured is corrected. However, the measuring device 100 according to the third embodiment calculates the pressure value of the second measured gas based on the concentration value of the first measured gas and the concentration difference ΔC of the second measured gas instead of the pressure difference ΔP. to correct. The concentration difference ΔC is the difference between the CO ₂ concentration in the first measurement gas measured by the preliminary measurement in step S2, and the 2 CO ₂ concentration in the measurement gas measured by the preliminary measurement in step S4.

The pressure correction unit 508 according to the second embodiment calculates the difference between the CO ₂ concentration of the first gas to be measured measured in advance in step S2 and the CO ₂ concentration of the _second gas to be measured measured in advance in step S4. Is calculated. In the example of FIG. 6, CO ₂ concentration in the first measurement gas is 2% CO ₂ concentration of the first gas to be measured, since it is 4%, as [Delta] C, 2% is calculated.

The measuring apparatus 100 according to the second embodiment stores a third correspondence table in which the third driving distance of the piston (in the pressure correction process) in a state where the valve V6 is opened and the concentration difference ΔC are associated. Is stored. FIG. 10 is a diagram illustrating an example of the third correspondence table. The third correspondence table is obtained by replacing the pressure difference ΔP in FIG. 8 with the concentration difference ΔC. In the example of FIG. 10, the density difference ΔC1 is associated with the third drive distance N1, and the density difference ΔC2 is associated with the third drive distance N2. In FIG. 8, a three-point reader is shown, and this three-point reader omits the association between the other density difference ΔC and the third drive distance. As a modified example, the pressure correction unit 508 may use the third correspondence expression instead of the correspondence table in FIG. The third correspondence equation is an equation for calculating the third driving distance N when the density difference ΔC is input.

The pressure correction unit 508 drives the third driving distance N (the cylinder 21b in a state where the valves V4 and V6 are opened, based on the calculated density difference ΔC using the third correspondence table or the third correspondence expression. Distance). The pressure correction unit 508 drives the piston 21c in the X2 direction from the initial position H with the valve V4 and the valve 6 opened in a state where the second gas to be measured is accommodated in the cylinder 21b. Therefore, while the valve V6 is open, the second gas to be measured is pumped into the cell 11, but is discharged to the outside via the valve V6 as it is. By opening the second drive distance T and the valve V6, the pressure of the second measured gas in the cell 11 becomes equal to the pressure of the first measured gas (= reference pressure value).

FIG. 12A is a diagram illustrating the driving of the piston 21c and the open / closed state of each valve in the pressure correction processing, the pressure feeding processing, and the pressurization processing according to the third embodiment.

In the third embodiment, as shown in FIG. 12A, in the pressure correction process for the second gas to be measured, the pressure correction unit 508 acquires the third drive amount N according to the concentration difference ΔC. In the pressure correction process of the third embodiment, the piston 21c is moved from the initial position H in the X2 direction over the third drive distance N shown in FIG. 12A with the valves V4 and V6 opened. Drive. Then, it is discharged outside via the valve V4, the cell 11, and the valve V6. By this discharge, the measuring apparatus 100 can make the pressure value of the first measured gas equal to the pressure value of the second measured gas.

圧力 The pressure correction unit 508 of the present embodiment acquires the third drive amount N based on the density difference ΔC. Therefore, unlike the first and second embodiments, it is not necessary to provide the pressure gauge 33 for measuring the pressure in the cylinder 21b. Therefore, the number of components can be reduced as compared with the measuring apparatus 100 of the first embodiment.

[Fourth embodiment]
Next, a measuring apparatus 100 according to a fourth embodiment will be described. The measuring device 100 of the third embodiment has been described as discharging the second gas to be measured in the cylinder 11 via the valve V6. The measuring device 100 of the fourth embodiment discharges the second gas to be measured in the cylinder 11 via the valve V5. FIG. 12B is a diagram illustrating the driving of the piston 21c and the open / closed state of each valve in the pressure correction processing, the pressure feeding processing, and the pressurization processing according to the second embodiment.

In the second embodiment, as shown in FIG. 12B, in the pressure correction process for the second gas to be measured, the pressure correction unit 508 opens the valve V5 and closes the valves V1 to V4 and the valve V6. In this state, the cylinder 21b is driven in the X2 direction. According to such a configuration, it is possible to discharge from the valve V5 by the pressure correction processing.

っても The measuring device 100 of the fourth embodiment also has the same effect as the measuring device 100 of the third embodiment.

(Modification)
(1) In the present embodiment, the pre-measurement has been described on the assumption that the amount of calculation in the measurement is smaller than the main measurement. However, the measurement processing may be shared between the preliminary measurement and the main measurement. With such a configuration, the measurement program can be shared between the preliminary measurement and the main measurement, so that the program capacity can be reduced.

(2) The measuring apparatus of the present embodiment reduces (dilutes) the concentration of the gas to be measured which has a higher component gas, out of the first gas to be measured and the second gas to be measured, to thereby dilute the first gas to be measured. The description has been made assuming that the concentrations of the component gases are the same in the measurement gas and the second measurement gas. However, if the concentration of the component gas of the first measured gas and the concentration of the component gas of the second measured gas are the same, any processing may be executed. For example, the measuring device adjusts the concentration of at least one component gas of the first measured gas and the second measured gas. Typically, the measuring device sends a component to the measured gas (in the present embodiment, the first measured gas) having the lower concentration of the component gas of the first measured gas and the second measured gas. By adding the gas, the concentration of the component gas of the first measured gas and the concentration of the component gas of the second measured gas may be made the same. In addition, the measurement device adds the component gas to the first measurement gas and dilutes the second measurement gas, and adjusts the concentration of the component gas of the first measurement gas and the component gas of the second measurement gas. May be made the same as the density.

(3) The measurement apparatus of the present embodiment reduces the first measured gas and the second measured gas by decreasing the pressure value of the measured gas having the higher pressure value in the cell 11 to thereby obtain the first measured gas and the second measured gas. The description has been made assuming that the pressure value of the gas to be measured and the second gas to be measured are the same. However, if the pressure value of the component gas of the first measured gas and the pressure value of the second measured gas are the same, any processing may be executed. For example, the measuring device adjusts the pressure value of at least one of the first measured gas and the second measured gas. Typically, the measuring device pressurizes the measured gas (in the present embodiment, the first measured gas) having the lower pressure value of the first measured gas and the second measured gas to reduce the pressure value. By increasing the pressure, the pressure value of the first measured gas and the pressure value of the second measured gas may be made equal. Further, the measuring device increases the pressure value of the first measured gas and decreases the pressure value of the second measured gas so that the first measured gas and the second measured gas have the same pressure value. You may make it.

{(4)} In the present embodiment, the pressurizing section has been described as being configured by the cylinder 21b, the piston 21c, and the like. However, the pressurizing section may have any configuration as long as the gas to be measured in the cell can be pressurized.

(5) In the present embodiment, it has been described that the two types of component gases are ¹² CO ₂ and ¹³ CO ₂ . However, the two types of component gases may be other component gases as long as they are preferably in an isotope relationship with each other.

{(6)} In the first embodiment, the drive circuit 50 has been described as measuring the pressure values of both the first measured gas and the second measured gas. However, the measuring apparatus 100 measures the pressure value of the measured gas (in the present embodiment, the second measured gas) having the higher concentration of the component gas of the first measured gas and the second measured gas, The pressure value of the gas to be measured having the lower concentration of the component gas (the first gas to be measured in this embodiment) may not be measured. The measuring device of the present embodiment has a pressure maintaining unit (pressure maintaining function) that keeps the pressure value in the cell 11 constant, as shown in FIG. The pressure maintaining unit sets the pressure value of the gas to be measured in the cell 11 to a reference pressure value. Therefore, the pressure value of the gas to be measured, which is the thinner of the component gases, becomes the reference pressure value without being measured. That is, even if the drive circuit 50 measures at least the pressure value of the measured gas having the higher concentration of the component gas, the same effect as that of the present embodiment can be obtained.

(7) Also, a cell containing a gas to be measured containing two kinds of component gases having an isotope relationship with each other is included, and the absorbance of transmitted light having a wavelength suitable for the gas to be measured in the cell is determined. Based on the above, a program that causes a measuring device that measures the concentrations of the two types of component gases of the gas to be measured in the cell to execute the following steps may be executed.

(7-1) This program includes a cell containing a gas to be measured containing two types of component gases having an isotope relationship with each other, and measures the absorbance of transmitted light having a wavelength suitable for the gas to be measured in the cell. The first measured gas collected as a measured gas is obtained by a measuring device (computer) that is executed by a measuring device that measures the concentrations of the two types of component gases of the measured gas in the cell based on the absorbance. A first measuring function for measuring the concentration of each of the component gases of the first and second measurement gases; the concentration of the component gas of the first measurement gas and the component gas of the second measurement gas measured by the first measurement function And a concentration adjusting function for adjusting the concentration of at least one component gas of the first measurement gas and the second measurement gas so that the concentration of the first measurement gas and the second measurement gas is the same. 1 A pressurizing function of pressurizing the measurement gas and the second measurement gas with a predetermined force in the accommodated cell, and at least a component gas of the first measurement gas and the second measurement gas A pressure measurement function for measuring a pressure value of the gas to be measured having a higher concentration of the gas, and a pressure difference between the first gas to be measured and the second gas to be measured measured by the pressure measurement function. A pressure correction function for correcting the pressure in at least one of the first measurement gas and the second measurement gas in the pressurization function; and the first measurement gas and the second measurement gas corrected by the pressure correction function. This is a program for executing a second measurement function for measuring the concentration ratio of the two types of component gases for each measurement gas.

(7-2) The program includes a cell containing a gas to be measured containing two types of component gases having an isotope relationship with each other, and transmits transmitted light having a wavelength suitable for the gas to be measured in the cell. A first measurement gas and a second measurement gas collected as measurement gases are measured by a measuring device for determining the absorbance and measuring the concentrations of the two types of component gases of the measurement gas in the cell based on the absorbance. A first measuring function for measuring the concentration of each component gas, and the concentration of the component gas of the first measurement gas and the concentration of the component gas of the second measurement gas measured by the first measurement function are the same. A concentration adjustment function for adjusting the concentration of at least one of the first measurement gas and the second measurement gas; and the first measurement gas and the concentration that have been adjusted by the concentration adjustment function. Second measured A pressurizing function for pressurizing the gas with a predetermined force in the cell accommodated therein, and a measurement target having a higher concentration of at least a component gas of the first measurement target gas and the second measurement target gas. A pressure measurement function for measuring a pressure value of the gas; and a first measurement gas and a second measurement gas based on a pressure difference between the first measurement gas and the second measurement gas measured by the pressure measurement function. A pressure correction function for correcting the pressure in at least one of the pressurized functions of the measured gas, and the first measured gas and the second measured gas, each of which has been corrected by the pressure correction function, It is a program for executing a second measurement function for measuring the concentration ratio of two types of component gases.

{(8)} The pressure correction unit of the present embodiment has been described as correcting the pressure value of the second measured gas in the cylinder 21b. However, the location for correcting the pressure value of the second gas to be measured may be another location, for example, inside the cell 11. In addition, without being limited to the above-described configuration, the measuring device 100 is configured such that the pressure value of the gas to be measured when injected into the cell 11 is equal to the reference pressure value, regardless of the measurement location of the measuring device 100 and the concentration of the component gas. Any configuration may be used as long as the correction is performed.

For example, the pressure correction unit reduces the pressure (degree of pressurization) by the pressurization control unit for the second gas to be measured, the pressure of which increases. The pressure value of the two measured gases may be the same.

The embodiments disclosed this time are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

{100} measuring device, 502 {first measuring unit, 504} concentration adjusting unit, 506} pressurizing control unit, 508} pressure correcting unit, 510} second measuring unit, 512} pressure measuring unit.

Claims

Including a cell containing a gas to be measured containing two types of component gases having an isotope relationship with each other, determining the absorbance of transmitted light having a wavelength suitable for the gas to be measured in the cell, based on the absorbance, A measurement device for measuring the concentrations of the two types of component gases of the gas to be measured in the cell,
A first measuring unit that measures the concentration of each of the component gases of the first measured gas and the second measured gas collected as the measured gas;
The first measurement target gas and the second measurement target gas are measured such that the concentration of the component gas of the first measurement target gas and the concentration of the component gas of the second measurement target gas measured by the first measurement unit are the same. A concentration adjusting unit for adjusting the concentration of at least one component gas of the measurement gas,
A pressurizing unit that pressurizes the first measured gas and the second measured gas that have been adjusted by the concentration adjusting unit with a predetermined force in the accommodated cell;
At least one of the first gas to be measured and the second gas to be measured based on a concentration difference between component gases of the first gas to be measured and the second gas to be measured measured by the first measuring unit. A pressure correction unit for correcting the pressure in the pressurizing unit,
A measuring apparatus comprising: a second measuring unit that measures a concentration ratio of the two types of component gases to each of the first gas to be measured and the second gas to be measured that have been corrected by the pressure correcting unit.
Including a cell containing a gas to be measured containing two types of component gases having an isotope relationship with each other, determining the absorbance of transmitted light having a wavelength suitable for the gas to be measured in the cell, based on the absorbance, A measurement device for measuring the concentrations of the two types of component gases of the gas to be measured in the cell,
A first measuring unit that measures the concentration of each of the component gases of the first measured gas and the second measured gas collected as the measured gas;
The first measurement target gas and the second measurement target gas are measured such that the concentration of the component gas of the first measurement target gas and the concentration of the component gas of the second measurement target gas measured by the first measurement unit are the same. A concentration adjusting unit for adjusting the concentration of at least one component gas of the measurement gas,
A pressurizing unit that pressurizes the first measured gas and the second measured gas that have been adjusted by the concentration adjusting unit with a predetermined force in the accommodated cell;
A pressure measuring unit that measures a pressure value of a gas to be measured having a higher concentration of at least a component gas among the first gas to be measured and the second gas to be measured;
The pressurizing unit of at least one of the first measured gas and the second measured gas based on a pressure difference between the first measured gas and the second measured gas measured by the pressure measuring unit. A pressure compensator for compensating the pressure at
A measuring apparatus comprising: a second measuring unit that measures a concentration ratio of the two types of component gases to each of the first gas to be measured and the second gas to be measured that have been corrected by the pressure correcting unit.
The pressure correction unit is configured to determine that the higher one of the pressure value of the first measured gas and the pressure value of the second measured gas in the cell pressurized by the pressurizing unit is the lower one. The measuring device according to claim 1, wherein the pressure at the pressurizing unit is corrected so as to have a pressure value of:
The concentration adjusting section is configured such that a higher one of a concentration of the component gas of the first measured gas and a concentration of the component gas of the second measured gas measured by the first measuring section is a lower concentration. The measuring device according to any one of claims 1 to 3, wherein the gas to be measured having a higher concentration is diluted with outside air so that
5. The pressure correction unit according to claim 4, wherein the pressure adjustment unit corrects a pressure in the pressurizing unit with respect to one of the first measurement gas and the second measurement gas diluted with outside air in the concentration adjustment unit. 6. The measuring device as described.
The pressurizing unit is
A cylinder for pumping the gas to be measured into the cell,
A piston inserted into the cylinder;
A driving unit for driving the piston,
The said drive part drives the said piston by the predetermined moving amount so that the pressure value in the said cell containing the to-be-measured gas may become the pressure value at the time of measuring the density | concentration of a component gas. The measuring device according to any one of claims 5 to 5.
The measuring device according to claim 6, wherein the pressure correction unit corrects the pressure at the pressurizing unit based on a movement amount of the piston.
The pressure compensating unit is configured to adjust a movement amount of the piston with respect to one of the first measured gas and the second measured gas, which has a higher pressure value in the cell pressurized by the pressurizing unit. The measuring device according to claim 7, which adjusts.
The measurement apparatus according to claim 8, wherein the pressure correction unit adjusts a movement amount of the piston in a process of accommodating a gas to be measured to be pressure-fed into a cell in the cylinder.
(10) The measuring device according to any one of (1) to (9), wherein the two types of component gases are 12CO2 and 13CO2.
Including a cell containing a gas to be measured containing two types of component gases having an isotope relationship with each other, determining the absorbance of transmitted light having a wavelength suitable for the gas to be measured in the cell, based on the absorbance, A measurement method for measuring the concentrations of the two types of component gases of a gas to be measured in a cell,
Measuring the concentration of the component gas of each of the first measured gas and the second measured gas collected as the measured gas;
At least one of the first gas to be measured and the second gas to be measured so that the measured concentration of the component gas of the first gas to be measured is equal to the concentration of the component gas of the second gas to be measured. Adjusting the concentration of the component gases of
Pressurizing the adjusted first gas to be measured and the second gas to be measured with a predetermined force in the accommodated cell;
The pressure in the cell of at least one of the first gas to be measured and the second gas to be measured based on the measured concentration difference of the component gas between the first gas to be measured and the second gas to be measured. Correcting
Measuring the concentration ratio of the two types of component gases for each of the first measured gas and the second measured gas that have been corrected.
Including a cell containing a gas to be measured containing two types of component gases having an isotope relationship with each other, determining the absorbance of transmitted light having a wavelength suitable for the gas to be measured in the cell, based on the absorbance, A measurement method for measuring the concentrations of the two types of component gases of a gas to be measured in a cell,
Measuring the concentration of the component gas of each of the first measured gas and the second measured gas collected as the measured gas;
At least one of the first gas to be measured and the second gas to be measured so that the measured concentration of the component gas of the first gas to be measured is equal to the concentration of the component gas of the second gas to be measured. Adjusting the concentration of the component gases of
Pressurizing the adjusted first gas to be measured and the second gas to be measured with a predetermined force in the accommodated cell;
Measuring a pressure value of each of the first measured gas and the second measured gas;
Based on the measured pressure difference between the first measured gas and the second measured gas, the pressure in the cell of at least one of the first measured gas and the second measured gas is corrected. Steps and
Measuring the concentration ratio of the two types of component gases for each of the first measured gas and the second measured gas that have been corrected.