JP2015219200A - Analysis device and calibration method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To calibrate in such a way that a component analysis can be highly accurately executed even when a particle state of a particulate substance changes in an analysis device performing a component analysis of particulate substances.SOLUTION: An analysis device 100 comprises: an irradiation unit 51; a detection unit 53; and a particulate state change-amount calculation unit. The irradiation unit 51 is configured to excite a particulate substance P in an air atmosphere to irradiate a primary X-ray X1 generating a fluorescence X-ray. The detection unit 53 is configured to detect intensity of secondary X-ray generated by irradiating a calibration sample with the primary X-ray X1, and passing through the air atmosphere. The particulate state change-amount calculation unit is configured to calculate an amount of change or change rate of secondary X-ray intensity due to a particulate state change of particle substances on the basis of first secondary X-ray intensity by irradiating the calibration sample with the primary X-ray at first timing and to be detected by the detection unit, and second secondary X-ray intensity by irradiating the calibration sample with the primary X-ray at second timing and to be detected by the detection unit.

Description

  The present invention relates to an analyzer for analyzing particulate matter, and a calibration method for calibrating the analyzer.

  In recent years, PM2.5, which is a suspended particulate material having a particle size in the air of 2.5 μm or less, has become a major environmental problem. And the apparatus which analyzes the density | concentration in the atmosphere of PM2.5 and the element contained in PM2.5 is developed for the purpose of grasping | ascertaining the condition of PM2.5. It is considered that the source of PM2.5 can be estimated by analyzing the elements contained in PM2.5.

  For example, Patent Document 1 discloses a measuring apparatus that continuously and automatically analyzes element types that constitute suspended particulate matter in the atmosphere. This measuring device is first classified into air containing the whole amount of coarse particles having a particle diameter of more than 2.5 μm and air containing fine particles of PM 2.5 or less by a classifier. Next, the measuring device collects the classified airborne particulate matter in the filter. Thereafter, the measuring device performs fluorescent element analysis of coarse particles and fine particles individually using an X-ray analyzer.

JP 2008-261712 A

Aggarwal, S. G, Mochida, M., Kitamori, Y., Kawamura, K., “Sapporo city aerosol particles Chemical Closure Study on Hygroscopic Properties (Hygroscopic Properties of Urban Aerosol, Part of Insaporo, Japan), Environmental Science and Technology (Envolent, Ent. p. 6920-6925

  The particulate state of the particulate matter contained in the atmosphere varies depending on the humidity of the atmospheric atmosphere. For example, as shown in the graph (FIG. 9) showing the relationship between the humidity and the moisture absorption coefficient disclosed in Non-Patent Document 1, depending on the composition of the particulate matter, the particulate matter may contain moisture. Absorb. As a result, the particle size of the particulate matter increases. In addition, there may be a deviation (that is, hysteresis) between the moisture absorption coefficient when the humidity is increased and the moisture absorption coefficient when the humidity is decreased. FIG. 9 is a diagram showing the relationship between humidity and moisture absorption coefficient.

  In a conventional measuring apparatus or the like, the measurement span is calibrated using a standard substance or the like every predetermined period, and component analysis is performed using the calibration result of the measurement span. In this case, if the state of the standard material when the measurement span is calibrated is different from the state of the particulate material when the component analysis is performed, the component analysis of the particulate material cannot be performed accurately.

  An object of the present invention is to perform calibration in an analyzer that performs component analysis of particulate matter so that component analysis can be performed with high accuracy even when the particle state of the particulate matter changes.

Hereinafter, a plurality of modes will be described as means for solving the problems. These aspects can be arbitrarily combined as necessary.
An analyzer according to an aspect of the present invention is an analyzer that performs component analysis of particulate matter based on fluorescent X-rays generated from the particulate matter. The analyzer includes an irradiation unit, a detection unit, and a particle state change calculation unit. The irradiation unit emits primary X-rays that excite the particulate matter and generate fluorescent X-rays in the air atmosphere. The detection unit detects a secondary X-ray intensity that is generated by irradiating the primary X-ray and passes through the atmosphere. The particle state change calculation unit irradiates the calibration sample with the primary X-ray at the first timing and detects the first secondary X-ray intensity detected by the detection unit, and the calibration sample at the second timing. Based on the second secondary X-ray intensity detected by the detector by irradiating primary X-rays to the secondary X-ray, the amount of change or rate of change of the secondary X-ray intensity due to the change in the particle state of the particulate matter is calculated. .

  In the analyzer, the particle state change calculation unit irradiates the calibration sample with the primary X-ray at the first timing and detects the first secondary X-ray intensity detected by the detection unit and the second timing. Based on the second secondary X-ray intensity detected by the detection unit by irradiating the calibration sample with the primary X-ray, the amount of change in the secondary X-ray intensity due to the change in the particle state of the particulate matter or The rate of change is calculated. Thereby, in the analyzer for analyzing the component of the particulate matter, calibration can be performed so that the component analysis can be executed with high accuracy even if the particle state of the particulate matter changes.

  The analysis apparatus may further include an environment measurement unit that measures an environmental parameter that defines an air atmosphere. In this case, the particle state change calculation unit is based on the first environment parameter measured by the environment measurement unit at the first timing and the second environment parameter measured by the environment measurement unit at the second timing. Then, the amount of change or rate of change of the secondary X-ray intensity is calculated.

A calibration method according to another aspect of the present invention is a calibration method for an analyzer that performs component analysis of particulate matter based on fluorescent X-rays generated from the particulate matter. The calibration method includes the following steps.
A step of measuring the first secondary X-ray intensity detected by irradiating the calibration sample with the primary X-ray at the first timing.
A step of measuring the second secondary X-ray intensity detected by irradiating the calibration sample with the primary X-ray at the second timing.
A step of calculating a change amount or a change rate of the secondary X-ray intensity due to a change in the particle state of the particulate matter based on the first secondary X-ray intensity and the second secondary X-ray intensity.
Thereby, in the analyzer for analyzing the component of the particulate matter, calibration can be performed so that the component analysis can be executed with high accuracy even if the particle state of the particulate matter changes.

  In an analyzer that performs component analysis of particulate matter, calibration can be performed so that component analysis can be performed accurately even if the particle state of the particulate matter changes.

The figure which shows the structure of an analyzer. The figure which shows the structure of a control part. The figure which shows the arrangement | positioning of the base material for span calibration and the collection filter at the time of execution of span calibration, the irradiation state of a primary X-ray, and the state of the detected X-ray. The flowchart which shows the component analysis method of a particulate matter. The figure which shows an example of the profile of the count result containing the fluorescent X ray from a particulate matter. The flowchart which shows the calibration method by the change of a particle state. The figure which shows arrangement | positioning of the base material for calibration at the time of correct | amending by the change of a particle state. The figure which shows typically the method of correct | amending the influence of the change of a particle state. The figure which shows the relationship between humidity and a moisture absorption coefficient.

(1) 1st Embodiment The structure of the analyzer 100 which concerns on 1st Embodiment is demonstrated using FIG. FIG. 1 is a diagram showing the configuration of the analyzer. The analysis apparatus 100 performs component analysis of the particulate matter P based on fluorescent X-rays generated from the particulate matter P by irradiating the particulate matter P (described later) with primary X-rays X1 (described later). It is. The analysis device 100 includes a collection filter 1, a sampling unit 3, an analysis unit 5, a filter moving unit 7, an environment measurement unit 8, and a control unit 9.

  The collection filter 1 collects the particulate matter P contained in the atmosphere sampled in the sampling unit 3 (described later). Therefore, the collection filter 1 has a collection layer 11 having holes that can trap the particulate matter P. As the material of the collection layer 11, for example, a fluorine-based resin (for example, tetrafluoroethylene resin (PTFE)) can be used.

  The thickness of the collection layer 11 is adjusted so that the absorption of X-rays such as primary X-rays and fluorescent X-rays in the collection layer 11 is a predetermined amount or less. In the present embodiment, the collection layer 11 has a thickness of about 3 to 35 μm, for example. Furthermore, the collection filter 1 has a reinforcing layer 13 that reinforces the collection layer 11 on the main surface of the collection layer 11. That is, the collection filter 1 has a two-layer structure having the collection layer 11 and the reinforcing layer 13.

  The thickness of the collection filter 1 including the collection layer 11 and the reinforcing layer 13 is adjusted to an average value of about 100 to 200 μm (for example, 140 μm) in order to make X-ray absorption by the collection filter 1 less than a predetermined amount. Has been. As the reinforcing layer 13, a material capable of gas flow, containing almost no element to be a measurement target element, and having sufficient strength is selected. As such a material, for example, a nonwoven fabric such as polyethylene, polypropylene, polyethylene terephthalate (PET), nylon, polyester, and polyamide can be used. In particular, a nonwoven fabric made of polypropylene and polyester does not contain impurities that cause noise in fluorescent X-ray analysis, and has sufficient strength, so that measurement with higher accuracy is possible.

  The sampling unit 3 samples the ambient atmosphere where the analyzer 100 is installed, and sprays the sampled atmosphere onto the collection filter 1. Thereby, the particulate matter P contained in the sampled air can be collected in the collection filter 1.

  Specifically, the first opening 31 a provided in the suction portion 31 is brought close to one main surface of the collection filter 1 in a state where the suction pump 33 is set to a negative pressure. Further, the second opening 35 a provided in the discharge unit 35 and connected to the sampling port 37 so as to allow gas flow is brought close to the other main surface of the collection filter 1. As a result, air is sucked from the sampling port 37 to the second opening 35a. The sucked air is blown to the other main surface of the collection filter 1 from the second opening 35a. As a result, the particulate matter P contained in the atmosphere is collected in the holes provided in the collection layer 11 of the collection filter 1. Further, the air passes through the collection filter 1 and is sucked into the suction unit 31.

  The first opening 31 a may be provided with a mesh-like support member that supports the collection filter 1. Thereby, the deformation | transformation, destruction, etc. of a filter by attracting | sucking the collection filter 1 can be prevented.

  The sampling unit 3 further includes a β-ray irradiation unit 38 and a β-ray detection unit 39. The β-ray irradiation unit 38 is provided in the second opening 35 a and irradiates the collection filter 1 with β-rays. The β-ray detection unit 39 is provided in the first opening 31a and detects β-rays that have passed through the collection filter 1 (and the particulate matter P).

  The analysis unit 5 performs component analysis of elements contained in the particulate matter P using fluorescent X-rays generated from the particulate matter P. In the present embodiment, the analysis unit 5 mainly performs component analysis of the metal elements contained in the particulate matter P. Examples of the metal elements contained in the particulate matter P in the atmosphere include sodium, aluminum, calcium, titanium, vanadium, manganese, zinc, lead, barium, antimony, lanthanum, and samarium. In addition, component analysis of elements other than metal elements such as sulfur, chlorine and bromine is also performed.

  By analyzing which element is contained in the particulate matter P, the origin of the particulate matter P collected by the collection filter 1 can be known. The configuration of the analysis unit 5 will be described in detail later.

  The filter moving unit 7 moves the particulate matter P collected by the collection filter 1. Specifically, the filter moving unit 7 sends out the collection filter 1 from a delivery reel 7a that is rotatably supported. The take-up reel 7 b that is rotatably supported winds the collection filter 1. As a result, the particulate matter P collected by the collection filter 1 is moved from the sampling unit 3 to the analysis unit 5.

  The environment measurement unit 8 measures environmental parameters of the analysis unit 5 and its surrounding area. The environmental parameter is a parameter that defines the atmospheric atmosphere of the analysis unit 5 and its surrounding area. Therefore, for example, the temperature, atmospheric pressure, and humidity of the analysis unit 5 and its surrounding area can be used as the environmental parameters. Therefore, the environment measuring unit 8 includes a thermometer, a barometer, and a hygrometer (all not shown).

  The control unit 9 performs various processes in the analysis apparatus 100. The configuration of the control unit 9 and the function of each component in the control unit 9 will be described in detail later.

(2) Configuration of Analysis Unit Next, the configuration of the analysis unit 5 will be described. The analysis unit 5 generates and detects fluorescent X-rays from the particulate matter P collected by the collection filter 1. Therefore, the analysis unit 5 includes an irradiation unit 51 and a detection unit 53. In the analysis unit 5, the irradiation unit 51 and the detection unit 53 are not housed in a casing or the like that is isolated from the external air atmosphere. Thereby, the analysis part 5 can perform the component analysis of the particulate matter P continuously and rapidly, without controlling internal atmosphere, such as the housing | casing which accommodated the irradiation part 51 and the detection part 53. FIG.

  The irradiation unit 51 irradiates the measurement region A with the primary X-ray X1 in the air atmosphere. The measurement region A is a region where the particulate matter P collected by the sampling unit 3 is sent by the filter moving unit 7 when component analysis is performed in the analyzer 100.

  In the present embodiment, the irradiation unit 51 is an X-ray generator. The X-ray generator is an apparatus that generates X-rays by irradiating an electron beam onto a target (metal such as palladium, rhodium, silver, tungsten, tantalum, copper, titanium, or chromium). Therefore, the primary X-rays X1 irradiated from the irradiation unit 51 include X-rays by bremsstrahlung and characteristic X-rays specific to the target.

  In addition, a primary filter (not shown) is provided at the exit where primary X-rays are emitted from the irradiating unit 51 to reduce the intensity of primary X-rays in the wavelength region corresponding to the wavelength of fluorescent X-rays generated from the measurement target element. doing. This is because it is sufficient for the primary X-ray to contain an X-ray component having higher energy than the fluorescent X-ray from the element to be measured. Thereby, the background component of the X-ray detected in the detection part 53 (after-mentioned) can be reduced.

  The detection unit 53 can detect the secondary X-ray X2 generated in the measurement region A and passing through the atmospheric atmosphere by being irradiated with the primary X-ray X1. Therefore, as the detection unit 53, for example, a semiconductor detector such as a silicon semiconductor detector or a silicon drift detector (SDD) can be used. In particular, by using the silicon drift detector SDD, it is not necessary to use liquid nitrogen or the like for cooling, so that the analyzer 100 can be made compact.

(3) Configuration of Control Unit Next, the configuration of the control unit 9 will be described with reference to FIG. FIG. 2 is a diagram illustrating a configuration of the control unit. The control unit 9 is a computer system having a CPU (Central Processing Unit), a storage device such as a RAM, a ROM, a hard disk, and an SSD (Sold State Disk), a display unit, various interfaces, and the like. Some or all of the functions of each component of the control unit 9 described below may be realized by a program stored in the storage device of the computer system. In addition, some or all of the functions of the components of the control unit 9 may be realized by a semiconductor device such as a custom IC.

The controller 9 includes a filter controller 91, a sampling controller 92, an irradiation controller 93, an X-ray counter 94, a component analyzer 95, a particle state change calculator 96, and a particle mass concentration calculator 97. Have
The filter control unit 91 controls the filter moving unit 7. Specifically, the filter control unit 91 outputs, for example, a take-up reel control signal for controlling the rotation of a motor or the like (not shown) that controls the rotation of the take-up reel 7 b to the filter moving unit 7.

  The sampling control unit 92 controls the sampling unit 3. Specifically, the sampling control unit 92 provides a flow rate control signal for adjusting the opening of a valve such as a needle valve provided in the middle of a pipe that connects the suction unit 31 and the suction pump 33 so as to allow gas flow. Output to the valve. Thereby, the suction force of the suction part 31 and the air flow rate in the sampling part 3 can be controlled.

  The irradiation control unit 93 controls the irradiation unit 51. Specifically, in the X-ray generator of the irradiation unit 51, the voltage and / or current applied to the electron beam source that generates the electron beam is controlled. Thereby, the intensity | strength of the primary X-ray X1 from the irradiation part 51 can be adjusted.

  The X-ray counter 94 counts the number of pulse signals output from the detector 53. Specifically, the X-ray counting unit 94 counts the number of pulse signals within a predetermined signal value range, and outputs the obtained result as a counting result.

  The component analysis unit 95 performs calibration of the analysis unit 5 and component analysis of the particulate matter P. The calibration method of the analysis unit 5 and the component analysis method of the particulate matter P in the component analysis unit 95 will be described in detail later.

  The particle state change calculation unit 96 irradiates the calibration sample with the primary X-ray at the first timing and detects the first secondary X-ray intensity detected by the detection unit 53, and at the second timing. Based on the second secondary X-ray intensity detected by the detector by irradiating the calibration sample CS with the primary X-ray, the amount of change in the secondary X-ray intensity due to the change in the particle state of the particulate matter P or Calculate the rate of change.

  The particle mass concentration calculation unit 97 receives the β-ray detection signal from the β-ray detection unit 39, and the particulate matter P collected by the collection filter 1 based on the intensity of the β-ray transmitted through the particulate matter P. The particle mass concentration of is measured.

(4) Operation of analyzer Basic Operation Next, the operation of the analyzer 100 will be described. When the operation of the analysis apparatus 100 is started, the component analysis unit 95, for example, when a predetermined time or more (for example, one month or more) has passed since the previous calibration execution, the span calibration base material SS (described later). ) And / or calibration using a background calibration substrate. If the predetermined time has not elapsed, the component analysis unit 95 starts component analysis of the particulate matter P.
Hereinafter, the calibration method and the component analysis method of the particulate matter P in the analyzer 100 will be described in detail.

II. Calibration The calibration of the analysis unit 5 in step S2 is mainly performed using the span calibration base material SS (FIG. 4) in which the calibration sample CS is laminated on the base material MS. Further, calibration using the background calibration base material BS is performed as necessary. Note that each calibration step described below is executed by the component analysis unit 95 unless otherwise indicated.

The span calibration base material SS is a calibration base material for performing span calibration. Therefore, the calibration sample CS, which is a standard material, is a particulate material containing at least the measurement target element. As such a calibration sample CS, for example, a standard substance defined by NIST (National Institute of Standards & Technology) can be used.
The base material MS of the span calibration base material SS is a (plate-like) base material made of a material (for example, polycarbonate) that is almost transparent to X-rays (that is, almost transparent to X-rays). .

  In the calibration of the analysis unit 5 in step S2, as shown in FIG. 3, the span calibration base material SS is arranged together with the collection filter 1, and the span calibration base material SS (the calibration sample CS) is collected. It is preferable to generate span calibration data by using the secondary X-ray X2 detected by the detection unit 53 when the primary X-ray X1 is irradiated to the collection filter 1. FIG. 3 is a diagram illustrating the arrangement of the span calibration base material and the collection filter, the irradiation state of primary X-rays, and the state of detected X-rays at the time of execution of span calibration. Thereby, span calibration data considering X-ray absorption of the collection filter 1 can be acquired.

  Next, the irradiation unit 51 irradiates the primary X-ray X1 with the span calibration base material SS arranged as described above, and the detection result of the secondary X-ray X2 generated thereby is detected by the detection unit 53. The data is stored in the storage device of the control unit 9 as span calibration data. In addition, the component analysis unit 95 inputs environmental parameters from the environment measurement unit 8 when the span calibration base material SS is irradiated with the primary X-ray X1 and stores the environmental parameters in a storage device or the like.

  On the other hand, the background calibration base material BS is a substantially transparent (plate-like) base material, for example, made of the same material (polycarbonate or the like) as the base material MS of the span calibration base material SS. is there. Background calibration is performed when background calibration data is not stored, or when the background or zero point deviates significantly from the previous calibration.

  When performing background calibration, similarly to when performing span calibration, the primary X-ray X1 is irradiated while the background calibration base material BS is disposed with the collection filter 1 and is detected by the detection unit 53. It is preferable to generate background calibration data using the secondary X-ray X2.

  Next, the primary X-ray X1 is irradiated with the background calibration base material BS arranged with the collection filter 1, and the counting result obtained by detecting the secondary X-ray X2 generated thereby by the detection unit 53 is backed up. The data for ground calibration is stored in a storage device of the control unit 9 or the like. In addition, the component analysis unit 95 inputs the environmental parameters when the background calibration base material BS is irradiated with the primary X-ray X1 from the environment measurement unit 8 and stores them in a storage device or the like.

After the background calibration data and the span calibration data are generated and stored in the storage device or the like, the component analysis unit 95 uses the background calibration data and the span calibration data to generate a calibration curve for each measurement target element. Generate.
Specifically, for example, in a background calibration data, the measured intensity of X-rays with an energy value E _a of the fluorescent X-rays from the target elements D are stored and B _a, the span calibration data, calibration measured element D during use sample CS is included only element amount a, the intensity of X-rays with an energy value E _a at this time is assumed to have been stored and I _a. In this case, a calibration curve showing the relationship between fluorescent X-ray intensity Y for element X of the measurement target elements of the _{above, Y = ((I a -B} a) / a) * of X + _{B a} produced as an expression.

III. Next, the component analysis of the particulate matter P will be described with reference to FIG. FIG. 4 is a flowchart showing a component analysis method for particulate matter.
When component analysis is started in the analyzer 100, the sampling control unit 92 first instructs the sampling unit 3 to collect the particulate matter P contained in the atmosphere in the collection filter 1 (step S301). To do. Thereafter, the filter control unit 91 instructs the filter moving unit 7 to move the collection area of the collection filter 1 to the measurement area A.

  Thereafter, the irradiation control unit 93 transmits an irradiation unit control signal to the irradiation unit 51. As a result, the primary X-ray X1 is irradiated onto the particulate matter P collected by the collection filter 1 (step S302), and fluorescent X-rays having energy values peculiar to the elements contained in the particulate matter P are generated. . In addition, the component analysis unit 95 receives the environmental parameters during measurement of fluorescent X-rays from the particulate matter P from the environment measurement unit 8 and stores them in a storage device or the like.

  In a state where the particulate matter P in the collection area is irradiated with the primary X-ray X1, the detection unit 53 detects the secondary X-ray X2 from the collection area (step S303). As a result, the X-ray counter 94 generates a count result as shown in FIG. FIG. 5 is a diagram illustrating an example of a profile of a counting result including fluorescent X-rays from particulate matter. In the X-ray profile shown in FIG. 5, fluorescent X-rays of iron, zinc, lead, and titanium are particularly prominent.

  After acquiring the counting result, the particle state change calculating unit 96 corrects the influence of the change in the particle state of the particulate matter P on the measured counting result (step S304). In step S304, the calibration curve is corrected in consideration of the influence of the change in the particle state. A specific correction method will be described later.

  Next, the component analysis unit 95 performs component analysis on the measurement target element (step S305). Specifically, first, the component analysis unit 95 corrects the X-ray intensity due to the influence of the change of the environmental parameter on the counting result shown in FIG. Specifically, the ratio of a reference X-ray profile (described later) at the time of execution of span calibration to a current X-ray profile (described later) that is an X-ray profile close to an environmental parameter at the time of component analysis is calculated as described above. Multiply the result.

  Next, the component analysis unit 95 performs component analysis of the measurement target element using the count result corrected by the influence of the change in the environmental parameter. When performing component analysis, the calibration curve corrected in step S304 is used.

  After performing the component analysis for each measurement target element of the particulate matter P, the component analysis unit 95 determines whether to perform another component analysis (step S306). For example, the component analysis unit 95 ends the component analysis when receiving a predetermined command from an input unit (not shown) of the control unit 9 or the like.

If it is determined that the component analysis has been completed (“No” in step S306), the component analysis in the analyzer 100 is terminated.
On the other hand, when the component analysis unit 95 determines not to receive the above command and execute another component analysis (in the case of “Yes” in step S306), the filter moving unit 7 moves the collection filter 1. Then, the particulate matter P having undergone component analysis is sent out from the measurement region A (step S307). Thereafter, the process returns to step S301. Thereby, the particulate matter P is again collected by the other area | region of the collection filter 1, and those other component analyzes can be performed. Thereby, in the analyzer 100, a some component analysis can be continuously performed for every predetermined time.

IV. Correction Method Based on Change in Particle State Next, the correction method based on the change in particle state executed in step S304 will be described with reference to FIG. FIG. 6 is a flowchart showing a correction method by changing the particle state. The following steps are executed by the particle state change calculation unit 96. When the correction of the change in the particle state is executed, it is first determined whether or not it is necessary to calculate the temporal change data (described later) (step S3041). For example, when component analysis is continuously performed, it can be determined that the time-dependent change data needs to be calculated when one or more days have elapsed since the previous time-dependent change data calculation.
Alternatively, time-change data may be calculated for each component analysis. By calculating temporal change data for each component analysis, even if the ambient environment (humidity, temperature, atmospheric pressure, etc.) of the analyzer 100 changes during the execution of continuous component analysis, the ambient environment for each component analysis is changed. It is possible to calculate temporal change data taking into account changes.

  If it is determined that the calculation of the time-varying data is necessary (“Yes” in step S3041), the process proceeds to step S3043 and the calculation of the time-varying data is started. On the other hand, when it is determined that it is not necessary to newly calculate temporal change data (in the case of “No” in step S3041), the currently stored temporal change data is read from the storage device or the like (step S3042).

Specifically, the calculation of the temporal change data in step S3043 is performed as follows, for example.
First, the reference X-ray intensity is read from a storage device or the like. For example, the background calibration data acquired (measured) at the time of executing the background calibration is read as the reference X-ray intensity.

  Next, the filter control unit 91 is instructed to move the collection filter 1 to move the non-collection area to the measurement area A. Thereafter, the irradiation control unit 93 is instructed to irradiate the non-collection region of the collection filter 1 with the primary X-ray X1. As a result, the primary X-ray X1 can be irradiated to the non-collection region where the particulate matter P is not collected in the collection filter 1. At this time, in the measurement region A, the scattered X-rays are generated as the secondary X-rays X2 by scattering the primary X-rays X1 in the non-collecting region. As a result, the counting result of scattered X-rays detected by the detection unit 53 can be acquired as scattered X-ray data.

  After acquiring the scattered X-ray data, the scattered X-ray data is corrected for the influence of the X-ray intensity change due to the change of the environmental parameter. Specifically, for each element to be measured, a reference X-ray profile that is an X-ray intensity profile in an environmental parameter close to the environmental parameter at the time of execution of span calibration, and an X in an environmental parameter close to the first environmental parameter of this time A ratio with the current X-ray profile which is a profile of the line intensity is calculated. After that, for each element to be measured, the ratio between the corrected data obtained by multiplying the scattered X-ray data by the ratio and the X-ray intensity of the background calibration data is calculated as time-change data and stored in a storage device or the like. .

  After calculating the temporal change data or reading the temporal change data, the intensity correction data is calculated (step S3044). Specifically, the temporal change data includes a reference X-ray profile that is an X-ray intensity profile close to the second environmental parameter and a current X-ray profile that is an X-ray intensity profile close to the first environmental parameter. By multiplying the ratio, the intensity correction data can be calculated.

  As described above, by calculating the temporal change data individually, the influence of the X-ray intensity due to the temporal change (time-dependent data) can be extracted. As a result, the intensity correction data can be calculated by reducing the measurement frequency of the X-ray intensity (scattered X-ray).

Next, as shown in FIG. 7, the span calibration substrate SS can be irradiated with primary X-rays X1 other than the measurement region A, and X-rays generated from the calibration sample CS can be detected by the detection unit 53. Install in a safe area. Thereafter, the irradiation controller 93 is instructed to generate the primary X-ray X1 (step S3045).
For example, the span calibration base material SS can be arranged in a region below the collection filter 1 and below the measurement region A. FIG. 7 is a diagram illustrating the arrangement of the calibration base material when correction is performed by changing the particle state. Thereby, the secondary X-ray X2 generated from the calibration sample CS can be detected as the first secondary X-ray in the detection unit 53. Further, by installing the span calibration base material SS in a place other than the measurement region A, the secondary X-ray X2 can be acquired while collecting the particulate matter P of the collection filter 1. In this case, in order to prevent the primary X-ray X1 and the like from passing through the span calibration base material SS and reaching the collection filter 1, a shielding plate is provided on the collection filter 1 side of the span calibration base material SS. Also good.
Since the span calibration base material SS is installed in an area other than the measurement area A, the obtained X-ray intensity is corrected by distance. Specifically, for example, the obtained count result is multiplied by a calculated value of exp (−μ (d−d ′)). μ is an X-ray attenuation constant, d is an X-ray path length from the irradiation unit 51 to the detection unit 53 when the span calibration base material SS is installed in the measurement region A, and d ′ is other than the measurement region A. This is the X-ray path length from the irradiation unit 51 to the detection unit 53 when the span calibration base material SS is installed. Alternatively, the intensity of the secondary X-ray X2 when the measurement area A is irradiated with the primary X-ray X1, and the intensity of the secondary X-ray X2 when the area other than the measurement area is irradiated with the primary X-ray X1 The ratio may be stored in advance, and the distance may be corrected using the ratio.

  After detecting the first secondary X-ray X2, the first secondary X-ray X2 is corrected by changing the environmental parameters using the intensity correction data (step S3046). That is, using the intensity correction data, X-ray data is calculated when it is assumed that the first secondary X-ray X2 is measured in the environmental parameter (second environmental parameter) at the time of span calibration (second timing). To do.

  Specifically, by correcting the intensity of the first secondary X-ray X2 by the intensity correction data, it is possible to execute correction based on the change in the environment change parameter.

Thereafter, the span calibration data stored in the storage device or the like is read out as the second secondary X-ray X2 (step S3047).
After reading the second secondary X-ray, the particle state change calculation unit 96 calculates the difference between the first secondary X-ray corrected by the change of the environmental parameter and the read second secondary X-ray. Based on the measurement target element, the influence of the change in the particle state of the particulate matter P is corrected (step S3048). This is because the influence on the fluorescent X-ray due to the change in the particle state differs for each element to be measured.

  Specifically, for example, a relational expression between the particle state of the particulate matter P (for example, state change due to humidity) and the slope and intercept of the calibration curve of each measurement target element as shown in FIG. Then, as shown in FIG. 8B, the slope (α) of the current calibration curve and the intensity of the first secondary X-ray corrected for the influence of the environmental parameter are appropriately placed on the calibration curve. The intercept (β) (calculated from the second secondary X-ray as span calibration data) is corrected to α ′ and β ′, respectively. FIG. 8 is a diagram schematically showing a method of correcting the influence of the change in the particle state.

  As described above, the calibration curve is corrected for each measurement target element in consideration of the influence of the change in the particle state, so that the analysis apparatus 100 can accurately perform even if the particle state of the particulate matter changes. Correction can be performed so that component analysis can be performed. In the above example, the change in the particle state is corrected based on the span calibration (second timing). However, the correction is performed based on the other timing (for example, the first timing). May be.

(5) Other Embodiments Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the scope of the invention. In particular, a plurality of embodiments and modifications described in this specification can be arbitrarily combined as necessary.

(A) Calibration of peak position in detection unit In the first embodiment described above, calibration is performed by changing the particle state. However, the present invention is not limited to this. For example, the peak position in the detection result (counting result) of the detection unit 53 (and / or the X-ray counting unit 94) may be calibrated.

Specifically, it can be performed using a peak included in the scattered X-rays generated by scattering the primary X-ray X1 in the collection filter 1. As a peak that can be used for the calibration of peak deviation, for example, an X-ray peak that has a known energy value at which a peak appears, such as a characteristic X-ray peak included in scattered X-rays, is unchanged.
By adjusting the span, zero point, etc. of the detection unit 53 and / or the X-ray counting unit 94 so that these X-ray peaks in the counting result appear at the above-mentioned known and unchanged energy values in the counting result, The peak position can be calibrated.

  The present invention can be widely applied to analyzers for analyzing particulate matter.

DESCRIPTION OF SYMBOLS 100 Analyzer 1 Collection filter 11 Collection layer 13 Reinforcement layer 3 Sampling part 31 Suction part 31a 1st opening part 33 Suction pump 35 Discharge part 35a 2nd opening part 37 Sampling port 38 (beta) ray irradiation part 39 (beta) ray detection part 5 Analysis unit 51 Irradiation unit 53 Detection unit 7 Filter moving unit 7a Delivery reel 7b Take-up reel 9 Control unit 91 Filter control unit 92 Sampling control unit 93 Irradiation control unit 94 X-ray counting unit 95 Component analysis unit 96 Particle state change calculation unit A Measurement area BS Background calibration substrate CS Calibration sample MS Substrate P Particulate matter SS Span calibration substrate X1 Primary X-ray X2 X-ray

Claims (3)

An analyzer that performs component analysis of the particulate matter based on fluorescent X-rays generated from the particulate matter,
An irradiation unit that emits primary X-rays that excite the particulate matter to generate fluorescent X-rays in an air atmosphere;
A detection unit that detects a secondary X-ray intensity generated by irradiating the primary X-ray and passing through the atmosphere;
The primary X-ray intensity is detected by the detection unit by irradiating the calibration sample with the primary X-ray at the first timing, and the primary X-ray is applied to the calibration sample at the second timing. Particle state change that calculates a change amount or rate of change of secondary X-ray intensity due to a change in particle state of the particulate matter based on the second secondary X-ray intensity detected by the detection unit by irradiation A calculation unit;
An analyzer comprising: An environment measuring unit for measuring an environmental parameter defining the atmospheric atmosphere;
The particle state change calculating unit includes a first environmental parameter measured by the environment measuring unit at the first timing and a second environmental parameter measured by the environment measuring unit at the second timing. The analyzer according to claim 1, wherein a change amount or a change rate of the secondary X-ray intensity is calculated based on the result. A calibration method for an analyzer that performs component analysis of the particulate matter based on fluorescent X-rays generated from the particulate matter,
Measuring a first secondary X-ray intensity detected by irradiating the calibration sample with primary X-rays at a first timing;
Measuring a second secondary X-ray intensity detected by irradiating the calibration sample with the primary X-ray at a second timing;
Calculating a change amount or a change rate of the secondary X-ray intensity due to a change in the particle state of the particulate matter based on the first secondary X-ray intensity and the second secondary X-ray intensity;
Calibration method including:

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