JP7011626B2 - Analytical equipment and analytical method - Google Patents

Description

The present invention relates to an analyzer and an analysis method for analyzing the concentration of one or a plurality of components to be measured contained in a sample.

Conventionally, as an analyzer for analyzing a sample such as exhaust gas of an automobile, for example, as shown in Patent Document 1, it is contained in the sample gas by performing multivariate analysis using an absorption spectrum obtained by irradiating the sample gas with light. There is one using the Fourier transform infrared spectroscopy (FTIR) method for calculating the concentration of the component to be measured. In this analyzer, various components contained in the sample are specified from each peak position (wave number) and the height of each peak position (wave number) of the obtained absorption spectrum data, and the concentration of each component is calculated.

Japanese Unexamined Patent Publication No. 4-262236

However, in the above-mentioned analyzer, when the concentration of the measurement target component in the sample is low, the noise becomes relatively large (that is, S / N) with respect to the peak caused by the measurement target component in the obtained absorption spectrum data. The ratio becomes large), and there is a problem that the analysis accuracy is lowered. Such a problem is not limited to an analyzer that analyzes a sample based on spectral data obtained by irradiating the sample with light, but is a problem that also occurs in other types of analyzers.

Therefore, the main object of the present invention is to improve the analysis accuracy in a low concentration range in an analyzer and an analysis method for analyzing the concentration of one or a plurality of components to be measured contained in a sample.

That is, the analyzer of the present invention analyzes the concentration of one or a plurality of measurement target components contained in a sample, and is a measurement cell into which the sample is introduced and an introduction path for introducing the sample into the measurement cell. , A derivation path for deriving the sample from the measurement cell, an opening / closing mechanism for opening and closing at least one of the introduction path or the derivation path, and spectral data obtained by irradiating the sample introduced in the measurement cell with light. Based on the above, the analysis unit that analyzes the concentration of the one or more measurement target components and the opening / closing mechanism are controlled, the introduction path and the lead-out path are opened, and the sample is continuously introduced into the measurement cell. In this state, the analysis unit closes at least one of the open mode for analyzing the concentration of the one or more measurement target components and the introduction path or the lead-out path, and the sample is made stationary in the measurement cell. It is characterized in that the analysis unit includes an open / close control unit that switches between a closing mode for analyzing the concentration of the one or a plurality of measurement target components in the state of being present.

With such a configuration, there is an open mode in which the concentration of the component to be measured is analyzed while the sample is continuously introduced into the measurement cell, and the component to be measured is measured while the sample is stationary in the measurement cell. Since the closing mode for analyzing the concentration can be switched, if the concentration of the component to be measured in the sample is low, the concentration analysis accuracy can be improved by switching to the closing mode. That is, in the closed mode, at least one of the introduction path and the lead path is closed and the sample is stationary in the measurement cell, so that a plurality of spectral data are acquired in a state where the concentration of the measurement target component in the sample is stabilized (that is,). , Multiple spectral data can be obtained from a sample with a constant concentration of various components), so by analyzing the sample based on these multiple spectral data, the peak wavelength due to the low concentration of the component to be measured can be obtained. The intensity can be increased and the influence of noise can be reduced to improve the S / N ratio, which can improve the analysis accuracy in the low concentration range. The "state in which the sample is stationary in the measurement cell" means a state in which the sample is not introduced into the measurement cell or a state in which the sample is not derived from the measurement cell.

In the analyzer, the analysis unit may acquire the spectrum data a plurality of times in the closed mode and analyze the concentration of the one or a plurality of measurement target components based on the spectrum data acquired a plurality of times. preferable.
In such a case, the peak wavelength intensity caused by the low concentration of the measurement target component is obtained by, for example, averaging a plurality of spectral data obtained for the sample in which the concentration of the measurement target component is stable. The effect of noise can be reduced and the S / N ratio can be improved, thereby improving the analysis accuracy in the low concentration range.

As an embodiment in which the effect of the analyzer of the present invention is remarkably exhibited, the number of times the analysis unit acquires the spectrum data in the closed mode is larger than the number of times the analysis unit acquires the spectrum data in the open mode. An example is to analyze the concentration of one or a plurality of components to be measured.

As a specific embodiment in which the effect of the analyzer of the present invention is remarkably exhibited, the analysis unit analyzes the spectral data in a multivariate manner and analyzes the concentration of the one or a plurality of components to be measured. More specifically, it is preferable that the analyzer is of the FTIR method.

As another specific embodiment in which the effect of the analyzer of the present invention is remarkably exhibited, the sample is in a gas (for example, automobile exhaust gas, etc.) in which the concentration of the component to be measured changes continuously (also referred to as aging). I can give you something.

The analyzer switches to the open mode when the opening / closing control unit switches to the open mode when the concentration of the measurement target component analyzed by the analysis unit is equal to or higher than a predetermined threshold, and the concentration of the measurement target component analyzed by the analysis unit. It is preferable to switch to the closed mode when is less than a predetermined threshold. In such a case, an excellent response is obtained by taking the open mode in a high concentration range where the influence of noise is small and good analysis accuracy can be exhibited. Analysis accuracy can be improved by achieving speed and closing in the low concentration range where the influence of noise is large, so while achieving the response speed required by standards, etc., in either the high concentration range or the low concentration range. Can also exhibit good analysis accuracy.

When the concentration of the component to be measured contained in the sample introduced into the measurement cell changes continuously (also referred to as aging), the analyzer achieves the response speed required by the standard or the like. Among them, it is required to demonstrate good analysis accuracy.
Therefore, in the closing mode, it is preferable that the lower the concentration of the measurement target component analyzed by the analysis unit, the longer the opening / closing control unit closes at least one of the introduction path and the lead-out path. ..
By doing so, when the concentration of the component to be measured is relatively low and the influence of noise is relatively large, the time for the sample to stand still in the measurement cell is lengthened, and a larger number of spectral data can be obtained. By acquiring it, the analysis accuracy can be improved. On the other hand, when the concentration of the component to be measured is relatively high and the influence of noise is relatively small, the response speed can be prioritized. Therefore, good analysis accuracy can be exhibited while achieving the response speed required by the standard and the like.

Further, the analysis method of the present invention includes a measurement cell into which a sample is introduced, an introduction path for introducing the sample into the measurement cell, a derivation path for deriving the sample from the measurement cell, and the introduction path or the derivation path. It is provided with an opening / closing mechanism for opening / closing at least one of the above, and an analysis unit for analyzing the concentration of the one or a plurality of measurement target components based on spectral data obtained by irradiating a sample introduced into the measurement cell with light. It is an analysis method that analyzes the concentration of one or more measurement target components contained in the sample using an analyzer, and controls the opening / closing mechanism to open the introduction path and the lead-out path, and the measurement cell. With the sample continuously introduced into the open mode, the analysis unit closes at least one of the open mode for analyzing the concentration of the one or a plurality of measurement target components and the introduction path or the lead-out path, and the measurement is performed. It is characterized in that the analysis unit switches between a closing mode for analyzing the concentration of the one or a plurality of measurement target components while the sample is stationary in the cell.
Then, in the analysis method, when the concentration of the measurement target component analyzed by the analysis unit is equal to or higher than a predetermined threshold value, the mode is switched to the open mode, and the concentration of the measurement target component analyzed by the analysis unit is less than the predetermined threshold value. If this is the case, it is preferable to switch to the closing mode.
With such an analysis method, the same effects as those of the above-mentioned analyzer of the present invention can be obtained.

According to the present invention configured as described above, it is possible to improve the analysis accuracy in the low concentration range in the analyzer and the analysis method for analyzing the concentration of one or a plurality of components to be measured contained in the sample.

The schematic diagram which shows the whole of the analyzer of this embodiment. The functional block diagram of the arithmetic processing unit in the same embodiment. The flowchart which shows the operation of the analyzer in the open mode in the same embodiment. The flowchart which shows the operation of the analyzer in the closed mode in the same embodiment. The functional block diagram of the arithmetic processing unit in another embodiment.

Hereinafter, the analyzer 100 according to the embodiment of the present invention will be described with reference to the drawings.

The analyzer 100 of the present embodiment is a Fourier transform infrared spectroscopic analyzer 100, which is a so-called FTIR. Specifically, as shown in FIG. 1, a light source 1, an interferometer 2 (spectral section), and measurement are performed. It includes a cell 3, a photodetector 4, an arithmetic processing device 5, and the like. Here, the analyzer 100 can simultaneously calculate the concentration (a concept including the number of particles) of one component or a plurality of components such as an inorganic compound, a lower hydrocarbon, a nitrogen compound, etc. contained in the exhaust gas of an automobile as a sample. Used as an analyzer. Hereinafter, each part will be described. In the sample analyzed by the analyzer 100 of the present embodiment, the concentration of the component to be measured contained therein changes continuously (also referred to as time-dependent).

The light source 1 emits light having a broad spectrum (continuous light including light having a large wave number), and for example, a tungsten iodine lamp or a high-luminance ceramic light source is used.

As shown in the figure, the interferometer 2 utilizes a so-called Michelson interferometer equipped with one half mirror 21 (beam splitter), a fixed mirror 22, and a moving mirror 23. The light from the light source 1 incident on the interferometer 2 is split into reflected light and transmitted light by the half mirror 21. One light is reflected by the fixed mirror 22, the other is reflected by the moving mirror 23, and returns to the half mirror 21 again. Then, these lights are combined and emitted from the interferometer 2.

The measurement cell 3 is a transparent cell into which a sample is introduced, and the light emitted from the interferometer 2 passes through the sample in the measurement cell 3 and is guided to the photodetector 4. The photodetector 4 is a so-called MCT photodetector here.

The measurement cell 3 is connected to an introduction path 31 for introducing the sample into the measurement cell 3 and a lead path 32 for deriving the sample from the measurement cell 3. The analyzer 100 further includes an opening / closing mechanism 6 for opening / closing the introduction path 31 and the lead path 32. The opening / closing mechanism 6 has an introduction path opening / closing valve 61 and a lead path opening / closing valve 62 that open / close the introduction path 31 and the lead path 32, respectively. Here, the introduction path on-off valve 61 and the lead-out path on-off valve 62 are both electrically driven valves, specifically, solenoid valves and electric valves.

The arithmetic processing device 5 includes an analog electric circuit having a buffer, an amplifier, and the like, a digital electric circuit having a CPU, a memory, a DSP, and the like, and an A / D converter or the like intervening between them. As shown in FIG. 2, the arithmetic processing unit 5 serves as an analysis unit 51 that analyzes a sample introduced in the measurement cell 3 by the cooperation of the CPU and its peripheral devices according to a predetermined program stored in the memory. Demonstrate the function of. The analysis unit 51 calculates transmitted light spectrum data indicating the spectrum of light transmitted through the sample from the output value of the light detector 4, calculates absorption spectrum data from the transmitted light spectrum data, and includes various types in the sample. The components of the above are specified, the concentration value of each component is calculated, and this is output to a display or the like.

When the moving mirror 23 is moved back and forth in a straight line and the light intensity transmitted through the sample is observed with the position of the moving mirror 23 as the horizontal axis, in the case of light with a single wave number, the light intensity draws a sine curve due to interference. On the other hand, since the actual light transmitted through the sample is continuous light, the sine curve is different for each wave number, so that the actual light intensity is the superposition of the sine curves drawn by each wave number, and the interference pattern (interferogram). Is in the form of a wave packet.

Specifically, the analysis unit 51 obtains the position of the moving mirror 23 by a distance measuring meter (not shown) such as a HeNe laser (not shown), and the light intensity at each position of the moving mirror 23 is determined by the light detector 4. The interference pattern obtained from these is obtained and converted into transmitted light spectrum data with each wave frequency component as the horizontal axis by high-speed Fourier transformation (FFT). Then, for example, the transmitted light spectrum data of the sample is further converted into the absorption spectrum data based on the transmitted light spectrum data measured in advance with the measurement cell 3 empty. Then, by applying the multivariate analysis method to the absorption spectrum data calculated in this way, various components contained in the sample are specified, and the concentration value of each component is calculated at the same time. The transmitted light spectrum data and the absorption spectrum data are calculated at predetermined time intervals according to the moving speed of the moving mirror 23, respectively.

However, in the analyzer 100 of the present embodiment, as shown in FIG. 2, is the concentration value of the predetermined measurement target component calculated by the analysis unit 51 less than the predetermined threshold value in order to improve the analysis accuracy in the low concentration region? The arithmetic processing apparatus 5 is further provided with a function as a determination unit 52 for determining whether or not, and an opening / closing control unit 53 for controlling the opening / closing state of the opening / closing mechanism 6 based on the determination result of the determination unit 52. Further, the analysis unit 51 is configured to determine a method for analyzing the concentration of the component to be measured in the sample based on the determination result of the determination unit 52. Hereinafter, each part will be described.

The determination unit 52 receives the concentration value data indicating the concentration value of one or a plurality of components calculated by the analysis unit 51, and among the concentrations of each component indicated by the concentration value data, the concentration of the component to be measured (for example, NO ₂ or the like). Compare the value with a given threshold. Then, it is determined whether or not the concentration value of the measurement target component is less than a predetermined threshold value, and the determination result data indicating the determination result is transmitted to the open / close control unit 53 and the analysis unit 51.

The measurement target component to be compared with a predetermined threshold value may be one kind or a plurality of kinds. When there are a plurality of types of measurement target components, the value of the predetermined threshold value may be set individually for each of the plurality of types of measurement target components, or is a value commonly set for the plurality of measurement target components. There may be. Further, the threshold value may be arbitrarily set by the user.

Here, the determination unit 52 has either high concentration determination data indicating that the acquired concentration value of the measurement target component is equal to or higher than the threshold value or low concentration determination data indicating that the concentration value of the measurement target component is less than the threshold value. Is transmitted as judgment result data. The low density determination data may include data indicating the magnitude of the difference between the calculated density value and the threshold value.

The open / close control unit 53 receives the determination result data from the determination unit 52, and transmits a control signal (open / close switching signal) to the open / close mechanism 6 based on the determination result data. Specifically, when the open / close control unit 53 receives the high concentration determination data, both the introduction path open / close valve 61 and the lead path open / close valve 62 are in an open state so that the sample continues to flow in the measurement cell 3. Send a control signal to.

On the other hand, when the on-off control unit 53 receives the low concentration determination data, both the introduction path on-off valve 61 and the lead-out path on-off valve 62 are predetermined in order to make the sample stationary (also referred to as retention) in the measurement cell 3. A control signal is transmitted so as to keep the closed state over a period of time (hereinafter, also referred to as “valve closing time t ₁ ”). Here, when both the introduction path on-off valve 61 and the lead-out path on-off valve 62 are already closed when the low concentration determination data is received, the on-off control unit 53 first opens and closes the introduction path on-off valve 61 and the lead-out path on-off valve 61. Both of the valves 62 are opened for a predetermined time (hereinafter, also referred to as “replacement time t ₂ ”), and after the replacement time t ₂ has elapsed, both the introduction path on-off valve 61 and the lead-out path on-off valve 62 are closed. _A control signal is transmitted so as to close over t1. As a result, the samples in the measurement cell 3 can be replaced. The open / close control unit 53 is configured to transmit time data indicating the valve closing time t ₁ and the replacement time t ₂ to the analysis unit 51.

Here, the opening / closing control unit 53 may determine the length of the valve closing time t ₁ based on the concentration value calculated by the analysis unit 51. For example, the open / close control unit 53 lengthens the valve closing time t ₁ as the difference between the calculated concentration value indicated by the low concentration determination data and the threshold value is larger (that is, the lower the concentration value of the component to be measured is lower). good. By doing so, the lower the concentration of the component to be measured, the longer the time for the analysis unit 51 to analyze in a state where both the introduction path on-off valve 61 and the lead-out path on-off valve 62 are closed.

Upon receiving the determination result data from the determination unit 52, the analysis unit 51 determines the concentration analysis method of the components in the sample based on the determination result data, and analyzes the concentration of the components in the sample based on the determined analysis method.

Specifically, when the analysis unit 51 receives the high concentration determination data, that is, when the opening / closing mechanism 6 is opened and the sample is continuously supplied to the measurement cell 3, the analysis unit 51 inputs the sample introduced into the measurement cell 3 in real time. The concentration value of the component in the sample is calculated immediately. Specifically, when the analysis unit 51 receives the output value from the light detector 4 and acquires (also referred to as calculation) one or more absorption spectrum data, the sample is sampled based on the one or more absorption spectrum data. The concentration value of the component of is calculated, and one concentration value data is output.

On the other hand, the analysis unit 51 was introduced into the measurement cell 3 when the low concentration determination data was received, that is, when the opening / closing mechanism 6 was closed over the valve closing time t ₁ and the sample remained in the measurement cell 3. _The sample is analyzed during the valve closure time t1 to calculate the concentration value of the components in the sample. Specifically, the analysis unit 51 acquires spectral data a plurality of times over time for the same sample staying in the measurement cell 3 during the valve closing time t ₁ , and the spectral data acquired multiple times. The concentration value of the component of the sample is calculated using, and one concentration value data is output. More specifically, one averaged absorption spectrum data obtained by integrating and averaging a plurality of acquired (also referred to as calculated) absorption spectrum data is calculated, and a sample is obtained based on this one averaged absorption spectrum data. Calculate the concentration value of the component to be measured inside. Here, when receiving the low-concentration determination data, the analysis unit 51 acquires the spectrum data more times than the number of times when the spectrum data is acquired when the high-concentration determination data is received. That is, the concentration value of the component to be measured in the sample is calculated based on a larger number of spectral data than when the high concentration determination data is received.

Next, the operation of the analyzer 100 having such a configuration will be described.

The analyzer 100 of the present embodiment measures in an open mode for analyzing the concentration of the component to be measured while the lead-out path 32 and the introduction path 31 are open, and in a state where the lead-out path 32 and the introduction path 31 are closed. One of the closing modes for analyzing the concentration of the target component can be taken, and the opening / closing control unit 53 controls the opening / closing state of the opening / closing mechanism 6, so that these modes can be switched. In the present embodiment, the open mode and the closed mode are automatically switched according to the magnitude of the concentration value of the component to be measured calculated by the analysis unit 51. The operation in each analysis mode will be described below.

(Open mode)
The analyzer 100 is configured to first start the analysis of the sample in the open mode. The operation of the analyzer 100 in the open mode will be described with reference to FIG.

In the open mode, the open / close control unit 53 first transmits a control signal to the open / close mechanism 6 to open the introduction path 31 and the lead path 32 so that the sample continuously flows into the measurement cell 3 (step S11). ..

In this state, the analysis unit 51 receives the output value of the photodetector 4 (step S12), and calculates the absorption spectrum data based on this (step S13). The analysis unit 51 simultaneously calculates the concentration values of one component or a plurality of components contained in the sample based on the calculated absorption spectrum data, and outputs this as concentration value data to the determination unit 52 (step S14).

The determination unit 52 compares the concentration value of the measurement target component indicated by the concentration value data with a predetermined threshold value, and determines whether or not the concentration value is less than the predetermined threshold value (step S15). In step S15, when the concentration value of the component to be measured is equal to or higher than the threshold value, the determination unit 52 transmits the high concentration determination data to the open / close control unit 53, and the operations of steps S11 to S14 are repeated.

On the other hand, when the concentration value of the component to be measured is less than the threshold value in step S15, the determination unit 52 transmits the low concentration determination data to the analysis unit 51 and the open / close control unit 53, and switches the analysis mode to the closing mode (step S16). ).

(Closed mode)
Next, with reference to FIG. 4, the operation of the analyzer 100 in the closed mode will be described.

When the open mode is switched to the closed mode, the open / close control unit 53 switches the introduction path 31 and the lead path 32 from the open state to the closed state so that the sample stays in the measurement cell 3 (step S21). _The open / close control unit 53 maintains the closed state of the introduction path 31 and the lead path 32 for the valve closing time (that is, the cell sealing time for sealing the cell) t1.

In this state, the analysis unit 51 receives the output value of the photodetector 4 (step S22), and continues to sequentially calculate the absorption spectrum data at a predetermined time _interval during the valve closing time t1 (steps S23 and S24). .. The analysis unit 51 averages a plurality of absorption spectrum data calculated during the valve closing time t ₁ to calculate one averaged absorption spectrum data (step S25). Then, the analysis unit 51 simultaneously calculates the concentration values of one component or a plurality of components contained in the sample based on one averaged absorption spectrum data, and outputs this as concentration value data to the determination unit 52 (step S26). ..

The determination unit 52 compares the concentration value of the measurement target component indicated by the concentration value data with a predetermined threshold value, and determines whether or not the concentration value is less than the threshold value (step S27). In step S27, when the concentration value of the component to be measured is less than the threshold value, the determination unit 52 transmits the low concentration determination data to the analysis unit 51 and the open / close control unit 53, and the operations of steps S21 to S26 are repeated. Here, in step S21 in the repetition, the open / close control unit 53 temporarily switches the introduction path 31 and the lead path 32 from the closed state to the open state, replaces the samples in the measurement cell 3, and then switches from the open state to the closed state. .. In this way, the sample is intermittently supplied to the measurement cell 3.

On the other hand, when the concentration value of the component to be measured is equal to or higher than the threshold value in step S27, the determination unit 52 transmits the high / low concentration determination data to the analysis unit 51 and the open / close control unit 53, and switches the analysis mode to the open mode (step S28). ).

According to the analyzer 100 of the present embodiment configured as described above, when the concentration of the component to be measured is less than a predetermined threshold value, the opening / closing mechanism 6 is closed and the sample is retained in the measurement cell 3. Since a plurality of absorption spectrum data are calculated in 1 and the concentration of each component is calculated based on the averaged absorption spectrum data, the influence of noise can be reduced. This makes it possible to improve the S / N ratio in the analysis in the low concentration range and improve the analysis accuracy.

On the other hand, when the concentration of the component to be measured is equal to or higher than a predetermined threshold value and the influence of noise on the absorption spectrum data is relatively small, the opening / closing mechanism 6 is opened and the sample is continuously flowed to the measurement cell 3 in real time. Since the analysis is performed, good analysis accuracy and response speed can be exhibited.

The present invention is not limited to the above embodiment.

In the above embodiment, in the closing mode, a plurality of absorption spectrum data are calculated during the valve closing time t1 and the concentration of _each component is calculated based on the averaged absorption spectrum data obtained by averaging the absorption spectrum data. Not limited to. In another embodiment, a plurality of transmitted light spectrum data are calculated during the valve closing time t ₁ , one averaged transmitted light spectrum data obtained by averaging the data is calculated, and the one averaged transmitted light spectrum data is calculated. May be used to calculate the concentration of each component. Alternatively, a plurality of concentration value data are calculated based on each of the absorption spectrum data calculated during the valve closing time t ₁ , and one averaged concentration value data obtained by averaging the data is calculated, and the averaged concentration value is calculated. The concentration of each component may be determined based on the data.

In the above embodiment, when the open / close control unit 53 receives the low concentration determination data, the opening / closing control unit 53 determines the length of the valve closing time t ₁ based on the calculated concentration value, but the present invention is not limited to this. In another embodiment, the open / close control unit 53 keeps the valve closing time t ₁ constant regardless of the calculated concentration value, and the analysis unit 51 uses the number of absorption spectrum data for averaging based on the calculated concentration value. May be changed. Specifically, the lower the calculated concentration value, the larger the _number of absorption spectrum data calculated during the valve closing time t1 may be increased.

In the above embodiment, when the open / close control unit 53 receives the low concentration determination data, the open / close control unit 53 transmits a control signal so as to close both the introduction path open / close valve 61 and the lead path open / close valve 62. Not limited to this, a control signal may be transmitted so as to close either the introduction path on-off valve 61 or the lead-out path on-off valve 62.

In the above-described embodiment, the arithmetic processing unit 5 has a function as a determination unit 52, and the open / close control unit 53 controls the open / close state of the open / close mechanism 6 based on the determination result of the determination unit 52 (that is, the open mode). It was automatically switched to the closed mode), but it is not limited to this. In another embodiment, the analyzer 100 may be configured to manually switch from open mode to closed mode.

Specifically, as shown in FIG. 5, the arithmetic processing unit 5 of another embodiment does not have a function as a determination unit 52, but has a function as a reception unit 54 for receiving input from a user. good. Specifically, the reception unit 54 receives analysis mode instruction data instructing analysis in either the open mode or the closed mode by input of the user. The analysis mode instruction data includes the above-mentioned time data indicating the valve closing time t ₁ and the replacement time t ₂ . The valve closing time t ₁ and the replacement time t ₂ indicated by the time data may be preset or may be input when the user inputs the analysis mode instruction data. When the reception unit 54 receives the analysis mode instruction data, it transmits the analysis mode instruction data to the analysis unit 51 and the open / close control unit 53. When the analysis mode instruction data is received, the analysis unit 51 and the open / close control unit 53 are configured to perform the same operation as when the low concentration determination data is received in the embodiment.

The analyzer 100 is not limited to the analysis of the exhaust gas of automobiles, but also analyzes the exhaust gas of internal combustion engines such as ships, aircraft, agricultural machinery and machine tools, and the exhaust gas of external combustion engines such as thermal power plants and exhaust gas of factories. There may be. Further, the analysis is not limited to the exhaust gas, and may be used to analyze an environmental gas in the atmosphere or a gas filled in a gas cylinder, and any mode may be used as long as the analysis target is a gas. Further, the analysis is not limited to gas and may be performed by analyzing a liquid. Further, the sample analyzed by the analyzer 100 is not limited to a sample in which the concentration of the contained component changes continuously, and the concentration of the contained component may be constant regardless of time.

The analyzer 100 according to the present invention is not limited to the one using the FTIR method, for example, a non-dispersive infrared absorption (NDIR) method, a quantum cascade laser infrared spectroscopy (QCL-IR) method, and a non-dispersive ultraviolet absorption (non-dispersive ultraviolet absorption) ( A plurality of components contained in a sample may be quantitatively analyzed by using an NDUV) method, an infrared spectroscopy (UVA) method, or the like. Further, the present invention is not limited to these, and a sample is analyzed by using a magnetic pressure (PMD) method, a zirconia method, or the like, or a condensed particle counter (CPC) may be used. The analyzer 100 according to the present invention may be used for quantitative analysis of one component contained in a sample.

In addition, the present invention is not limited to the above-described embodiment, and it goes without saying that various modifications can be made without departing from the spirit of the present invention.

100 ・ ・ ・ Analytical device 3 ・ ・ ・ Measurement cell 31 ・ ・ ・ Introduction path 32 ・ ・ ・ Derivation path 51 ・ ・ ・ Analysis unit 6 ・ ・ ・ Opening / closing mechanism

Claims (7)

An analyzer that analyzes the concentration of one or more components to be measured contained in a sample.
The measurement cell into which the sample is introduced and the measurement cell
An introduction path for introducing the sample into the measurement cell,
A derivation path for deriving the sample from the measurement cell,
An opening / closing mechanism that opens / closes at least one of the introduction path and the lead path, and
An analysis unit that analyzes the concentration of the one or more measurement target components based on the spectral data obtained by irradiating the sample introduced into the measurement cell with light.
By controlling the opening / closing mechanism,
An open mode in which the analysis unit analyzes the concentration of the one or a plurality of measurement target components in a state where the introduction path and the lead-out path are opened and samples are continuously introduced into the measurement cell.
With at least one of the introduction path and the lead-out path closed and the sample stationary in the measurement cell, the analysis unit switches between the closing mode in which the concentration of the one or a plurality of measurement target components is analyzed. Equipped with an open / close control unit
The open / close control unit switches to the open mode when the concentration of the measurement target component analyzed by the analysis unit is equal to or higher than a predetermined threshold value, and the concentration of the measurement target component analyzed by the analysis unit is less than the predetermined threshold value. An analyzer that switches to the closing mode when the above is true . The first aspect of the present invention, wherein the analysis unit acquires the spectrum data a plurality of times in the closing mode and analyzes the concentration of the one or a plurality of measurement target components based on the spectrum data acquired a plurality of times. Analysis equipment. 2. The analysis unit analyzes the concentration of the one or a plurality of measurement target components by increasing the number of times the spectrum data is acquired in the closed mode more than the number of times the spectrum data is acquired in the open mode. The analyzer described in. The analyzer according to any one of claims 1 to 3, wherein the analysis unit analyzes the spectral data in a multivariate manner and analyzes the concentration of the one or a plurality of measurement target components. The analyzer according to any one of claims 1 to 4, wherein the sample is a gas in which the concentration of the component to be measured changes continuously. The opening / closing control unit claims that in the closing mode, the lower the concentration of the measurement target component analyzed by the analysis unit, the longer the time for closing at least one of the introduction path and the lead-out path. The analyzer according to any one of 5 to 5 . An opening / closing mechanism that opens and closes at least one of a measurement cell into which a sample is introduced, an introduction path for introducing the sample into the measurement cell, a lead-out path for deriving the sample from the measurement cell, and the introduction path or the lead-out path. And an analyzer provided with an analysis unit that analyzes the concentration of one or more measurement target components contained in the sample based on the spectral data obtained by irradiating the sample introduced into the measurement cell with light. It is an analysis method for analyzing the concentration of one or a plurality of components to be measured contained in the sample.
By controlling the opening / closing mechanism,
An open mode in which the analysis unit analyzes the concentration of the one or a plurality of measurement target components in a state where the introduction path and the lead-out path are opened and samples are continuously introduced into the measurement cell.
With at least one of the introduction path and the lead-out path closed and the sample stationary in the measurement cell, the analysis unit switches to a closing mode in which the concentration of the one or a plurality of measurement target components is analyzed. ,
When the concentration of the measurement target component analyzed by the analysis unit is equal to or higher than a predetermined threshold value, the mode is switched to the open mode, and when the concentration of the measurement target component analyzed by the analysis unit is less than the predetermined threshold value, the closure is performed. Analysis method to switch to mode .

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