JP2021047027A - Particle analysis device - Google Patents

Abstract

To measure an amount of a substance as an object to be measured included in a particle as an object to be measured with high accuracy.SOLUTION: A particle analysis device which receives radiant light and scattered light to analyze a substance as an object to be measured comprises: a radiant light receiving part which measures a received light intensity of the radiant light in at least two wavelength ranges; a scattered light receiving part which measures a received light intensity of the scattered light; and an analysis part which switches between an analysis in a first analysis mode in which to analyze an amount of the substance as the object to be measured from the radiant light or an analysis in a second analysis mode in which to analyze an amount of substance as the object to be measured from the scattered light according to an intensity ratio of the received light intensity of the radiant light in a first wavelength range to the received light intensity of the radiant light in a second wavelength range.SELECTED DRAWING: Figure 1

Description

The present invention relates to a particle analyzer that analyzes the amount of a substance to be measured contained in the particles to be measured by detecting radiated light or scattered light generated when the particles to be measured pass through an irradiation region of laser light.
[Prior art literature]
[Patent Document]
Japanese Unexamined Patent Publication No. 2012-88178 International Publication No. 2009-021123 [Non-Patent Document] Gao et al., Aerosol Science and Technology, 41: 2, pp. 125-135, 2007 Moteki & Kondo, Aerosol Science and Technology, 44: 8, pp. 663-675, 2010 Yoshida et al., Aerosol Science and Technology, Vol.50, No.3, i-iv, 2016 Hwa-Chi Wang & Walter John, Aerosol Science and Technology, 6: 2, pp. 191-198, 1987

It is preferable that the particle analyzer can accurately measure the amount of the substance to be measured contained in the particles to be measured even when the particle size of the particles to be measured is equal to or larger than the maximum incandescent limit particle size.

In the first aspect of the present invention, a particle analyzer is provided. The particle to be measured may contain a substance to be measured. The particle analyzer may analyze the substance to be measured by receiving the radiated light and the scattered light emitted when the particles to be measured pass through the laser beam. The particle analyzer may include a radiant light receiving unit. The radiant light receiving unit may measure the light receiving intensity of radiated light in at least two wavelength bands. The particle analyzer may include a scattered light receiver. The scattered light receiving unit may measure the light receiving intensity of the scattered light. The particle analyzer may include an analyzer. The analysis unit analyzes the amount of the substance to be measured from the radiated light according to the intensity ratio of the received intensity of the radiated light in the first wavelength band and the received intensity of the radiated light in the second wavelength band. You may switch between analyzing in the mode and analyzing in the second analysis mode in which the amount of the substance to be measured is analyzed from the scattered light.

The analysis unit may analyze in the first analysis mode when the intensity ratio is within the boiling point range. The analysis unit may analyze in the second analysis mode when the intensity ratio is out of the boiling point range. The boiling point range may include a value whose intensity ratio corresponds to the boiling point of the substance to be measured.

In the first analysis mode, the analysis unit may analyze the amount of the substance to be measured based on the peak value of the received intensity of the radiated light.

In the second analysis mode, the analysis unit may calculate the amount of the substance to be measured from the size of the particle to be measured and the ratio of the substance to be measured to the particle to be measured. In the second analysis mode, the analysis unit may calculate the size of the measurement target particle based on the moving speed of the measurement target particle.

In the second analysis mode, the analysis unit has a reference peak value, which is the peak value of scattered light when the ratio of the substance to be measured to the particles to be measured is the reference ratio, and a wave of scattered light received by the scattered light receiving unit. The ratio of the substance to be measured to the particles to be measured may be calculated based on the high value of the measured wave, which is a high value.

In the second analysis mode, the analysis unit uses reference radiant light, which is radiant light when the ratio of the substance to be measured to the particles to be measured is the reference ratio, and measurement radiant light, which is radiant light received by the radiant light receiving unit. Based on the above, the ratio of the substance to be measured to the particles to be measured may be calculated. In the second analysis mode, the analysis unit may calculate the ratio of the substance to be measured to the particles to be measured based on the reference temperature calculated from the reference radiant light and the measurement temperature calculated from the measurement radiant light.

The analysis unit may analyze the amount of the substance to be measured from the time change of the light receiving intensity of the radiated light or the scattered light.

At least one wavelength band may be a wavelength band equal to or higher than the peak wavelength of the substance to be measured at the boiling point temperature of the substance to be measured. At least one wavelength band may be a wavelength band below the peak wavelength. At least two wavelength bands may be wavelength bands equal to or higher than the peak wavelength of the substance to be measured at the boiling point temperature of the substance to be measured. The radiant light receiving unit may set at least one wavelength band according to the sensitivity of the light receiving intensity of the radiated light receiving unit.

The radiant light receiving unit may measure the light receiving intensity of radiated light in three wavelength bands. At least one wavelength band may include the peak wavelength of the non-measurement target substance at the boiling point temperature of the non-measurement target substance contained in the measurement target particle.

The non-measurement target substance may be iron. The substance to be measured may be black carbon.

The outline of the above invention does not list all the necessary features of the present invention. Sub-combinations of these feature groups can also be inventions.

It is a figure which shows an example of the structure of the particle analyzer 100 which concerns on one Embodiment of this invention. It is a flowchart which shows an example of the process which the analysis unit 10 analyzes the amount of the substance to be measured. It is a figure which shows an example of the relationship between a radiated light signal of a different temperature, and a signal intensity. This is an example of measuring the light receiving intensity of radiated light in two wavelength bands. This is another example of measuring the light receiving intensity of radiated light in two wavelength bands. This is an example of measuring the light receiving intensity of radiated light in three wavelength bands. It is a figure which shows the relationship between the particle diameter and the scattering intensity of black carbon and a standard particle. It is a figure which shows an example of the particle 102 to be measured. It is a figure which shows an example of the particle 202 to measure. This is an example of a light receiving signal when the particle 102 to be measured is equal to or less than the maximum incandescent limit particle size. This is an example of a light receiving signal when the particle 202 to be measured is equal to or less than the maximum incandescent limit particle size. This is an example of a light receiving signal when the particle 102 to be measured has a maximum incandescent particle size or more. This is an example of a light receiving signal when the particle 202 to be measured has a maximum incandescent particle size or more. It is a flowchart which shows an example of the process which the analysis unit 10 calculates the internal mixing ratio based on the measured peak value of scattered light. It is a flowchart which shows an example of the process which the analysis unit 10 calculates the internal mixing ratio based on the measured radiant light. It is a figure which shows the relationship between a particle temperature and I _Blue / I _Red. It is a figure which shows an example of the structure of the speed detection unit 9. It is a figure which shows the method of calculating the moving speed of the particle 2 to be measured based on the output of the differential calculation unit 51.

Hereinafter, the present invention will be described through embodiments of the invention, but the following embodiments do not limit the inventions that fall within the scope of the claims. Also, not all combinations of features described in the embodiments are essential to the means of solving the invention.

FIG. 1 is a diagram showing an example of the configuration of the particle analyzer 100 according to one embodiment of the present invention. The particle analyzer 100 of this example includes a particle introduction nozzle 1, an analysis unit 10, a radiant light receiving unit 20a, a radiated light receiving unit 20b, a scattered light receiving unit 30, a laser irradiation unit 40, and a mirror 50. The particle analyzer 100 measures the measurement target based on the radiated light and the scattered light generated when the measurement target particle 2 introduced from the particle introduction nozzle 1 passes through the irradiation region of the laser light 3 irradiated from the laser irradiation unit 40. Particle 2 is analyzed.

The particle 2 to be measured is a particle introduced from the particle introduction nozzle 1 and to be measured. The particle 2 to be measured may be fine particles in a gas. The fine particles in the gas are called aerosols. The particle size of the particle 2 to be measured may be 1 μm or more and 100 μm or less, and more specifically, 5 μm or more and 100 μm or less. The average particle size of the particles may be about 10 μm.

The particle 2 to be measured may contain a substance to be measured. The substance to be measured is a substance to be measured by the analysis unit 10. The measurement target particle 2 may contain black carbon (soot) as a measurement target substance. The measurement of black carbon (soot) generated when carbon-based fuel is incompletely burned, such as diesel engine exhaust gas, coal combustion, forest fire, combustion of fuel such as firewood and biomass fuel, is combustion. It is important as an indicator of efficiency.

Black carbon has the property of absorbing light well and being heated. The boiling point temperature of black carbon is about 4000 K. Therefore, when the black carbon is irradiated with a powerful laser beam 3 such as a laser cavity or a pulse laser, the black carbon is instantaneously heated to 4000 K and vaporized. The heated black carbon generates incandescent light as radiant light by blackbody radiation. Incandescent light is radiated light generated by blackbody radiation when black carbon reaches the boiling point temperature. By detecting incandescent light, the amount of black carbon can be quantified. The method of detecting incandescent light of black carbon is called a laser-induced incandescent method (LII method).

In the LII method, the amount of black carbon is quantified by increasing the amount of radiated light when the black carbon reaches the boiling point temperature according to the particle size. However, as the particle size increases, the heat capacity also increases, so if the energy absorbed by the black carbon when crossing the laser is not sufficient for the heat capacity of the black carbon, it cannot be heated to the boiling point temperature. It may not generate incandescent light. Assuming that the maximum incandescent particle size is the particle size of the maximum black carbon that can be heated to the boiling point temperature of 4000 K, it is difficult to analyze black carbon having a maximum incandescent particle size or more by radiant light.

The laser irradiation unit 40 irradiates the sample gas containing the measurement target particles 2 introduced into the particle analyzer 100 with the laser light 3 at a wavelength in the near infrared region used in the LII method. The laser irradiation unit 40 may include a light source using an Nd: YVO4 laser. The laser irradiation unit 40 may include a light source using a YAG laser. Further, a mirror 50 for forming a laser resonator may be provided at an end opposite to the light source. The wavelength of the laser beam 3 is, for example, 1064 nm.

The particle introduction nozzle 1 introduces a sample gas containing the particles 2 to be measured into the laser beam 3. The particle introduction nozzle 1 may convey the particle 2 to be measured. The particle introduction nozzle 1 may be provided with a classification device for selecting the particle size of the particles 2 to be measured to be introduced. In FIG. 1, the axis parallel to the optical axis of the laser beam 3 is defined as the X axis. Further, the two axes perpendicular to the X axis are defined as the Y axis and the Z axis. In this example, the surface of the radiant light receiving unit 20a including the radiant light receiving element 7a and the optical axis of the laser light 3 is the XZ surface. The radiant light receiving element 7b of the radiated light receiving unit 20b, the scattered light receiving element 8 of the scattered light receiving unit 30, and the speed detecting unit 9 may also be arranged on the XZ surface. In FIG. 1, the gas passage is extended in the Z-axis direction between the radiant light receiving unit 20a and the radiated light receiving unit 20b, but the gas passage may be extended in the Y-axis direction. That is, it is desirable that the central axis direction 21 of the gas passage is the Y-axis direction. This is to avoid interference between the optical paths of the radiated light and the scattered light and the particle introduction nozzle 1. In this case, the particle 2 to be measured is included in the air flow along the Y-axis direction and passes through the irradiation region of the laser beam 3.

The radiant light receiving unit 20a receives the radiated light generated when the measurement target particle 2 passes through the irradiation region of the laser light 3. The radiant light receiving unit 20a includes an objective lens 4a, a condensing lens 5a, a radiant light receiving element 7a, and an optical filter 11. After being collimated by the objective lens 4a, the radiated light passes through only a specific wavelength band by the optical filter 11, and is condensed by the condensing lens 5a on the radiated light receiving element 7a. The signal received by the radiant light receiving element 7a is transmitted to the analysis unit 10. An objective lens 4a, a condenser lens 5a, and an optical filter 11 may be provided between the incident surface of the radiant light receiving element 7a and the laser beam 3. The optical filter 11 may be provided between the objective lens 4a and the condenser lens 5a. The radiant light receiving element 7a may be a photomultiplier tube (PMT).

The optical filter 11 may transmit only radiated light in a specific wavelength band. The optical filter 11 may transmit only radiated light in the wavelength band of 400 nm to 550 nm, which is the wavelength on the blue side of visible light. The optical filter 11 may be a bandpass filter that transmits only radiated light in the wavelength band of 400 nm to 550 nm. The optical filter 11 may be a combination of an optical filter that transmits only radiant light in a wavelength band of 400 nm or more and an optical filter that transmits only radiant light in a wavelength band of 550 nm or less. Further, the optical filter 11 may block scattered light in the wavelength range in the near infrared region.

The radiant light receiving unit 20b receives the radiated light generated when the measurement target particle 2 passes through the irradiation region of the laser light 3. The radiant light receiving unit 20b includes an objective lens 4a, a condensing lens 5a, a radiant light receiving element 7b, and an optical filter 12. After being collimated by the objective lens 4a, the radiated light passes through only a specific wavelength band by the optical filter 12, and is condensed by the condensing lens 5a on the radiated light receiving element 7b. The signal received by the radiant light receiving element 7b is transmitted to the analysis unit 10. An objective lens 4a, a condenser lens 5a, and an optical filter 12 may be provided between the incident surface of the radiant light receiving element 7b and the laser beam 3. The optical filter 12 may be provided between the objective lens 4a and the condenser lens 5a. The radiant light receiving element 7b may be a photomultiplier tube (PMT). The configuration of the radiant light receiving unit 20b may be the same as that of the radiated light receiving unit 20a except for the optical filter 12. The radiant light receiving element 7a and the radiant light receiving element 7b may be the same.

The optical filter 12 may transmit only radiated light in a wavelength band different from the wavelength band transmitted by the optical filter 11. The optical filter 12 may transmit only radiated light in a wavelength band of 550 nm or more, which is the wavelength on the red side of visible light. The optical filter 12 may be an optical filter that transmits only radiated light in a wavelength band of 550 nm or more. Further, in the wavelength band of 550 nm or more, it is sufficient that the wavelengths of the laser beam 3 (808 nm and 1064 nm) can be excluded. As the optical filter 12, an optical filter that transmits only radiated light in a wavelength band of 780 nm or less may be further used. The wavelength of the laser beam 3 may be excluded from the characteristics of the radiant light receiving element 7b. Further, the optical filter 12 may block scattered light in the wavelength range in the near infrared region.

Since the radiant light receiving unit 20a and the radiated light receiving unit 20b have optical filters that transmit radiated light in different wavelength bands, the light receiving intensity of the radiated light can be measured in at least two wavelength bands. The result of each light receiving intensity is transmitted to the analysis unit 10. The analysis content of the analysis unit 10 will be described later.

In FIG. 1, the radiant light receiving unit 20a and the radiated light receiving unit 20b each have a separate objective lens 4a, but the objective lens 4a may be shared. In this case, a dichroic mirror may be used to condense only the radiated light of a specific wavelength band on the radiated light receiving element 7a and the radiated light receiving element 7b. A dichroic mirror may be used to transmit only radiant light in the wavelength band of 550 nm or less and reflect only radiant light in the wavelength band of 550 nm or more. A dichroic mirror may be used to reflect only radiant light in the wavelength band of 550 nm or less and transmit only radiant light in the wavelength band of 550 nm or more.

The scattered light receiving unit 30 receives the scattered light generated when the measurement target particle 2 passes through the irradiation region of the laser light 3. The scattered light receiving unit 30 includes an objective lens 4b, a condenser lens 5b, an optical filter 6, a scattered light receiving element 8 and a speed detecting unit 9. After the scattered light is collimated by the objective lens 4b, only the scattered light passes through the optical filter 6, and is condensed by the condensing lens 5b on the scattered light receiving element 8 or the speed detection unit 9. The signal received by the scattered light receiving element 8 or the speed detection unit 9 is transmitted to the analysis unit 10. An objective lens 4b, a condenser lens 5b, and an optical filter 6 may be provided between the incident surface of the scattered light receiving element 8 and the laser beam 3. An objective lens 4b, a condenser lens 5b, and an optical filter 6 may be provided between the incident surface of the velocity detection unit 9 and the laser beam 3. The optical filter 6 may be provided between the objective lens 4b and the condenser lens 5b.

The optical filter 6 may transmit scattered light in the wavelength range of the near infrared region. Further, the optical filter 6 may block radiated light in the wavelength range of visible light.

The scattered light receiving element 8 can measure the light receiving intensity of the scattered light. The measurement result of the light receiving intensity of the scattered light is transmitted to the analysis unit 10. The analysis content of the analysis unit 10 will be described later. The scattered light receiving element 8 may be an avalanche photodiode (APD).

The velocity detection unit 9 can measure the moving velocity of the particle 2 to be measured. The measurement result of the moving speed of the particle 2 to be measured is transmitted to the analysis unit 10. The analysis content of the analysis unit 10 will be described later. The velocity detection unit 9 may measure the moving velocity of the particle 2 to be measured by a known method. The velocity detection unit 9 may have two or more detection units for detecting the measurement target particle 2. The speed detection unit 9 may have two or more avalanche photodiodes (APDs). The configuration of the speed detection unit 9 will be described later.

The analysis unit 10 analyzes the amount of the substance to be measured (black carbon) from the time change of the light receiving intensity of the radiated light or the scattered light. The time change of the light receiving intensity of the radiated light is transmitted from the radiated light receiving element 7a or the radiated light receiving element 7b. The time change of the light receiving intensity of the scattered light is transmitted from the scattered light light receiving element 8.

FIG. 2 is a flowchart showing an example of a process in which the analysis unit 10 analyzes the amount of the substance to be measured. Since the radiant light receiving unit 20a and the radiated light receiving unit 20b have optical filters that transmit radiated light in different wavelength bands, the light receiving intensity of the radiated light can be measured in at least two wavelength bands. The received intensity of the radiated light may be the peak value which is the maximum signal intensity in each wavelength band. Therefore, it is possible to calculate the intensity ratio between the light receiving intensity of the radiant light in the first wavelength band and the light receiving intensity of the radiant light in the second wavelength band (step S101). The analysis unit 10 may calculate the intensity ratio of the received intensity of the radiated light in the first wavelength band to the received intensity of the radiated light in the second wavelength band. The radiant light receiving unit 20a may measure the light receiving intensity of the radiant light in the first wavelength band, and the radiant light receiving unit 20b may measure the receiving intensity of the radiated light in the second wavelength band. The first wavelength band may be a wavelength band transmitted by the optical filter 11, and the second wavelength band may be a wavelength band transmitted by the optical filter 12.

Assuming that all the particles 2 to be measured pass through the center of the beam and the laser intensity experienced by the particles 2 to be measured does not change, in the case of particles having a maximum incandescent particle size or less, the light received by the radiant light in the first wavelength band. The intensity ratio between the intensity and the received intensity of the radiated light in the second wavelength band is a value corresponding to the boiling point peculiar to the substance to be measured (black carbon), and therefore is a constant value. On the other hand, in the case of particles above the maximum incandescent limit, the intensity ratio of the received intensity of radiant light in the first wavelength band to the received intensity of radiated light in the second wavelength band is equal to or less than the maximum incandescent particle size. It changes compared to the case of the particles of. Therefore, by analyzing the intensity ratio of the light receiving intensity of the radiant light in the first wavelength band and the light receiving intensity of the radiant light in the second wavelength band, does the particle 2 to be measured correspond to the boiling point peculiar to black carbon? Can be determined.

It is determined whether the intensity ratio of the received intensity of the radiated light in the first wavelength band and the received intensity of the radiated light in the second wavelength band corresponds to the boiling point of black carbon (step S102). The determination may be performed by the analysis unit 10. Depending on the determination result of whether the intensity ratio is equivalent to the black carbon boiling point, the analysis unit 10 analyzes in the first analysis mode in which the amount of the substance to be measured is analyzed from the radiated light, or analyzes the amount of the substance to be measured from the scattered light. You may switch whether to analyze in the second analysis mode.

The intensity ratio has an error due to the detection optical system, signal processing, and the like. Therefore, it is desirable to have a range for determining whether the strength ratio is equivalent to the boiling point of black carbon. When the intensity ratio is within the boiling point range including the value corresponding to the boiling point of black carbon, the analysis may be performed in the first analysis mode, and when the intensity ratio is outside the boiling point range, the analysis may be performed in the second analysis mode.

When the intensity ratio of the received intensity of the radiated light in the first wavelength band to the received intensity of the radiated light in the second wavelength band is equivalent to the black carbon boiling point, the amount of the substance to be measured is analyzed from the radiated light. The amount of black carbon is calculated in the first analysis mode. That is, it may be determined that the black carbon has been sufficiently heated, and the amount of black carbon may be analyzed based on the peak value of the light receiving intensity of the radiated light.

In the first analysis mode, first, the peak value of the light receiving intensity of the radiated light is acquired (step S103). The peak value of the light receiving intensity of the radiated light may be acquired in either the first wavelength band or the second wavelength band. From the viewpoint of S / N ratio, it is desirable to use a wavelength band with a stronger light receiving intensity. Next, the amount of black carbon is calculated based on the peak value of the light receiving intensity of the radiated light (step S104). The conversion coefficient from the peak value of the received intensity of the radiated light to the amount of black carbon may be derived in advance by deriving a calibration curve using standard particles having a known amount of black carbon contained. The amount of black carbon is calculated by multiplying the peak value of the received intensity of the radiated light by the conversion coefficient. When the analysis unit 10 calculates the amount of black carbon, the measurement ends.

When the intensity ratio of the received intensity of the radiated light in the first wavelength band to the received intensity of the radiated light in the second wavelength band is not equivalent to the black carbon boiling point, the amount of the substance to be measured is analyzed from the scattered light. 2 Calculate the amount of black carbon in the analysis mode. That is, it may be determined that the heating of the black carbon is insufficient, and the amount of black carbon may be analyzed based on the scattered light.

In the second analysis mode, first, it is determined whether the intensity ratio of the light receiving intensity of the radiant light in the first wavelength band and the light receiving intensity of the radiant light in the second wavelength band corresponds to the boiling point of the iron particles (step S105). .. When it is equivalent to the boiling point of iron particles, it is difficult to separate the signals of iron particles and black carbon. Therefore, the measurement result of the particles is excluded and the measurement is terminated. If it is not equivalent to the boiling point of iron particles, the process proceeds to step S106, and the amount of black carbon is analyzed based on the scattered light. If the iron particles contained in the measurement target particle 2 are negligible with respect to the measurement accuracy, step S105 may not be mounted.

When the ratio of the light receiving intensity of the radiant light in the first wavelength band to the light receiving intensity of the radiant light in the second wavelength band is not equivalent to the boiling point of the iron particles, the moving speed of the particle 2 to be measured is measured (step). S106). The speed detection unit 9 measures the moving speed of the particle 2 to be measured, and transmits the result to the analysis unit 10. There is a certain correlation between the moving speed of the measurement target particle 2 and the particle size of the measurement target particle. Therefore, if the correlation is acquired in advance, the particle size of the measurement target particle 2 can be converted and calculated from the moving speed of the measurement target particle 2. The analysis unit 10 calculates the particle size (size) of the measurement target particle 2 from the moving speed of the measurement target particle 2 (step S107).

By multiplying the particle size of the measurement target particle 2 obtained in step S107 by the ratio of black carbon to the measurement target particle 2 (internal mixing ratio), a more accurate estimation of the amount of black carbon becomes possible. Here, when the internal mixing ratio is 100%, it means that all of the measurement target particles 2 are substances to be measured, and when the internal mixing ratio is 0%, the measurement target particles 2 do not contain the measurement target substances. Means that. The calculation of the internal mixing ratio is considered to be almost unchanged when the properties of the object to be measured are relatively homogeneous, such as exhaust gas and powder industrial products, and other analytical methods that can measure the amount of black carbon in advance (thermal optical reflection). The average internal mixing ratio may be experimentally obtained by such means and uniformly multiplied. However, in the above method, when the properties of the particle 2 to be measured change, the internal mixing ratio may not be constant and the measurement accuracy may decrease.

The analysis unit 10 may calculate the internal mixing ratio in the second analysis mode (step S108). The analysis unit 10 may calculate the internal mixing ratio based on the measured peak value, which is the peak value of the scattered light received by the scattered light receiving unit 30, in the second analysis mode. The analysis unit 10 may calculate the internal mixing ratio based on the measurement radiant light which is the radiant light received by the radiant light receiving unit 20 in the second analysis mode. In the second analysis mode, the analysis unit 10 may calculate the internal mixing ratio based on the measurement temperature calculated from the measurement radiant light. In the second analysis mode, the analysis unit 10 uses either or both of the peak value of the scattered light received by the scattered light receiving unit 30 and the measured radiated light which is the radiated light received by the radiated light receiving unit. The mixing ratio may be calculated.

A case where the internal mixing ratio is calculated based on the measured peak value, which is the peak value of the scattered light received by the scattered light receiving unit 30, will be described. Based on the particle size of the particle 2 to be measured obtained in step S107, the theoretical peak value when the internal mixing ratio is 100% and the theoretical peak value when the internal mixing ratio is 0% are calculated. By comparing the theoretical peak value with the actually measured peak value, it is possible to measure the internal mixing ratio. The measured peak value is measured from the scattered light receiving element 8. Basically, it is considered that the measured crest value of the particle 2 to be measured is a crest value between the theoretical crest value when the internal mixing ratio is 100% and the theoretical crest value when the internal mixing ratio is 0%. As an example, the internal mixing ratio of the particle 2 to be measured can be estimated from the ratio of each crest value.

A case where the internal mixing ratio is calculated based on the measured radiant light which is the radiant light received by the radiant light receiving units 20a and 20b will be described. The measurement temperature, which is the temperature of the particle 2 to be measured, is calculated from the intensity ratio of the light reception intensity of the radiant light in the first wavelength band and the light reception intensity of the radiant light in the second wavelength band. Further, the theoretical temperature when the internal mixing ratio is 100% assumed from the particle size of the measurement target particle 2 obtained in step S107 is calculated. The theoretical temperature is calculated from the heat capacity of the particle 2 to be measured and the theoretical absorbed energy (calorific value). The heat capacity of the measurement target particle 2 is determined according to the volume of the measurement target particle 2. That is, the heat capacity of the particle 2 to be measured can be calculated from the particle size. The analysis unit 10 may store information such as a mathematical formula or a table showing the relationship between the particle size of the particle 2 to be measured and the heat capacity. The theoretical absorbed energy (calorific value) of the measurement target particle 2 is the amount of heat absorbed by the measurement target particle 2 from the laser beam 3. The theoretical absorption energy can be calculated from the product of the intensity of the laser beam 3 and the time required for the particle 2 to be measured to pass through the irradiation region of the laser beam 3. The intensity of the laser beam 3 can be detected from the control information of the laser irradiation unit 40. The transit time can be detected from the width of the irradiation region and the moving speed of the particle 2 to be measured. The width of the irradiation region may be stored in advance in the analysis unit 10. The analysis unit 10 may store information such as a mathematical formula or a table showing the relationship between the product of the intensity and transit time of the laser beam 3 and the absorbed energy. The internal mixing ratio can be calculated by comparing the measured temperature with the theoretical temperature. As an example, the internal mixing ratio of the particles 2 to be measured can be estimated from the ratio of each temperature. Further, as the theoretical temperature, the theoretical temperature when the internal mixing ratio is 0% may be used.

The amount of black carbon is calculated by multiplying the particle size of the particle 2 to be measured calculated in step S107 by the internal mixing ratio calculated in step S108 (step S109). When the analysis unit 10 calculates the amount of black carbon, the measurement ends. Summarizing steps S105 to S109, the analysis unit 10 may calculate the amount of the substance to be measured from the particle size (magnitude) of the particle 2 to be measured and the internal mixing ratio in the second analysis mode.

As described above, the analysis unit 10 depends on the determination result of whether the intensity ratio of the received intensity of the radiated light in the first wavelength band and the received intensity of the radiated light in the second wavelength band is equivalent to the black carbon boiling point. Switches between the analysis in the first analysis mode in which the amount of the substance to be measured is analyzed from the radiated light and the analysis in the second analysis mode in which the amount of the substance to be measured is analyzed from the scattered light. Therefore, even when the particle size of the measurement target particle 2 is equal to or larger than the maximum incandescent limit particle size, the amount of the measurement target substance (black carbon) contained in the measurement target particle 2 can be accurately measured. Further, since the internal mixing ratio is calculated in the second analysis mode, the amount of the substance to be measured can be accurately measured even when the properties of the particle 2 to be measured change.

FIG. 3 is a diagram showing an example of the relationship between radiated light signals at different temperatures and signal intensities. The radiant light receiving unit 20a and the radiated light receiving unit 20b receive the radiated light signal. The solid line is an example of a radiated light signal when the _{temperature T = T 1.} As an example, T ₁ is 4000K. The dotted line is an example of a radiated light signal when the _{temperature T = T 2.} As an example, T ₂ is lower than 4000K and 3500K.

T ₁ is 4000 K, which is equivalent to the boiling point of black carbon. Assuming that the peak value of the peak wavelength of the radiated light signal is I _λ , I _λ increases according to the particle size when the temperature is equivalent to the boiling point of black carbon. Therefore, the amount of black carbon can be quantified by measuring _{I λ} at the _{temperature T 1.} That is, when the temperature is T ₁ , the analysis unit 10 performs analysis in the first analysis mode.

T ₂ has not reached the boiling point of black carbon. Therefore, _{even if I λ} at the _{temperature T 2} is measured, the amount of black carbon cannot be quantified. That is, when the temperature is T ₂ , the analysis unit 10 performs analysis in the second analysis mode. Further, the peak wavelength of the radiant light signal at the _{temperature T 2} shifts to a longer wavelength side than the peak wavelength of the radiant light signal at the _{temperature T 1.} Further, _{I λ} at the _{temperature T 2} is lower than _{I λ} at the temperature T _1.

FIG. 4 is an example of measuring the light receiving intensity of radiated light in two wavelength bands. The radiated light signal in FIG. 4 is an example of a radiated light signal when T = T ₁ (corresponding to the boiling point of black carbon). The received intensity of the radiated light may be the peak value which is the maximum signal intensity in each wavelength band. Boundary wavelength λ ₁ is the wavelength of the boundary that separates the two wavelength bands. In the example of FIG. 4, the radiant light receiving unit 20a receives radiant light in _{a wavelength band having a boundary wavelength λ 1} or less, and the radiant light receiving unit 20b receives radiated light in a wavelength band having a _{boundary wavelength λ 1 or more.} The boundary wavelength λ ₁ is, for example, 550 nm. The peak value of the signal intensity received by the radiant light receiving unit 20a is I _Blue , and the peak value of the signal intensity received by the radiated light receiving unit 20b is I _Red . In FIG. 4, I _Red coincides with the peak value of the peak wavelength of the radiated light signal.

As for _{the ratio of I Blue} and I _Red , if the temperature is a value corresponding to the boiling point peculiar to black carbon, the peak wavelength of the radiated light signal is peculiar to black carbon and becomes a constant value. Therefore, _{based on the ratio of I Blue} and I _Red , the analysis unit 10 analyzes in the first analysis mode for analyzing the amount of the substance to be measured from the radiated light, or analyzes the amount of the substance to be measured from the scattered light. 2 You may switch whether to analyze in the analysis mode.

In the example of FIG. 4, the boundary wavelength λ ₁ is on the short wavelength side of the peak wavelength of the radiated light signal. Therefore, at least one wavelength band may be a wavelength band equal to or higher than the peak wavelength of the substance to be measured at the boiling point temperature of the substance to be measured. Further, at least one wavelength band may be a wavelength band equal to or lower than the peak wavelength.

Further, as shown in FIG. 3, when the temperature becomes low, the peak wavelength shifts to the long wavelength side. Therefore, at least two wavelength bands may be wavelength bands equal to or higher than the peak wavelength of the substance to be measured at the boiling point temperature of the substance to be measured. In this case, the boundary wavelength λ _{1 is set} to the long wavelength side of the peak wavelength of the material to be measured, and a new optical filter is added to the radiant light receiving unit 20a and the radiated light receiving unit 20b to cut the wavelength band below the peak wavelength of the material to be measured. May be added to.

FIG. 5 is another example of measuring the light receiving intensity of radiated light in two wavelength bands. The radiated light signal of FIG. 5 is _{another example of the radiated light signal when T = T 1} (corresponding to the boiling point of black carbon). The wavelength-intensity waveform of the radiated light signal is affected by the wavelength-sensitivity characteristics of the radiated light receiving units 20a and 20b. The radiant light receiving units 20a and 20b of this example have low sensitivity characteristics on the low wavelength side. Therefore, the signal intensity in FIG. 5 changes sharply in the wavelength band below the peak wavelength as compared with FIG. Therefore, when the radiant light receiving unit 20a receives radiated light in _{a wavelength band of the boundary wavelength λ 1} or less, the I _Blue becomes a small value. When I _Blue is a small value, it is easily buried in noise, so high-precision measurement cannot be performed.

In the example of FIG. 5, the radiant light receiving unit 20a receives the radiated light in _{the wavelength band of the boundary wavelength λ 2} or less, and the radiated light receiving unit 20b receives the radiated light in the wavelength band of the _{wavelength λ 2 or more.} The boundary wavelength λ ₂ is on the longer wavelength side than the boundary wavelength λ _1. In the example of FIG. 5, since the signal intensity changes sharply in the wavelength band below the peak wavelength, it is possible to perform highly accurate measurement by shifting the boundary wavelength to the longer wavelength side. At least one wavelength band may be set according to the sensitivity of the light receiving intensity of the radiated light receiving unit.

FIG. 6 is an example of measuring the light receiving intensity of radiated light in three wavelength bands. The radiated light signal of FIG. 6 is _{another example of the radiated light signal when T = T 1} (corresponding to the boiling point of black carbon). The radiated light signal of FIG. 6 has two peak wavelengths. As an example, the peak wavelength on the short wavelength side is the peak wavelength peculiar to black carbon, and the peak wavelength on the long wavelength side is the peak wavelength peculiar to the non-measurement target substance. In the example of FIG. 6, since I _Red '> I _Red , if the boundary wavelength is set to _{only λ 1} , the intensity ratio is calculated at the peak peculiar to the non-measurement target substance, and accurate measurement cannot be performed.

In the example of FIG. 6 _{, the boundary wavelength λ 3} is set in addition to the boundary wavelength λ _1. The boundary wavelength λ ₃ is, for example, on the shorter wavelength side than the peak wavelength peculiar to the substance to be measured. In this case, _{a radiant light receiving unit that receives a wavelength band having a boundary wavelength λ 3} or more may be newly added, and the light receiving intensity of the radiated light may be measured in the three wavelength bands. Accurate measurement is possible by measuring the light receiving intensity of radiated light in three wavelength bands. At least one of the three wavelength bands may include the peak wavelength of the non-measurement target substance at the boiling point temperature of the non-measurement target substance contained in the measurement target particle 2.

FIG. 7 is a diagram showing the relationship between the particle size of black carbon and standard particles and the scattering intensity. Black carbon having a maximum incandescent particle size or less is a particle having a wavelength equal to or less than the wavelength (1064 nm) generally used in the LII method, and is mainly a Rayleigh scattering region. The effect of the refractive index on the intensity is not large. In FIG. 7, the standard particle having the same scattered light intensity as black carbon 0.2 μm is 0.22 μm. Therefore, for black carbon having a maximum incandescent limit particle size or less, the error is small even if the particle size is calculated from the scattered light intensity.

However, in the case of the maximum incandescent limit particle size, since the particle size is about the same as or larger than the wavelength, the Mie scattering region changes to the geometrical optics scattering region. Therefore, the influence of the refractive index on the scattered light intensity becomes large. In FIG. 7, the standard particle having the same scattered light intensity as 10 μm of black carbon is 3.9 μm. Therefore, the error of black carbon having the maximum incandescent limit particle size becomes large when the particle size is calculated based on the scattered light intensity. Therefore, when analyzing the amount of the substance to be measured from the scattered light, it is preferable to accurately measure the internal mixing ratio.

FIG. 8 is a diagram showing an example of the particle 102 to be measured. The particle 102 to be measured contains the substance 103 to be measured. The substance to be measured 103 is, for example, black carbon. In the example of FIG. 8, all the particles 102 to be measured are the substances 103 to be measured. In the example of FIG. 8, the internal mixing ratio is 100%.

FIG. 9 is a diagram showing an example of the particle 202 to be measured. The measurement target particle 202 includes the measurement target substance 203 and the non-measurement target substance 204. The substance to be measured 203 is, for example, black carbon. The non-measurement target substance 204 is, for example, iron. In the example of FIG. 8, the internal mixing ratio is X%. X is a value between 0 and 100.

FIG. 10 is an example of a light receiving signal when the particle 102 to be measured is equal to or smaller than the maximum incandescent limit particle size. In FIG. 10, the measured value of the radiated light signal is represented by a thick line, and the scattered light signal is represented by a thin line. Further, the measured value of the scattered light signal is represented by a solid line, and the theoretical value of the scattered light signal is represented by a dotted line.

In FIG. 10, assuming that the peak value of the peak wavelength of the radiated light signal is I _λ , the amount of black carbon can be quantified by measuring _{I λ.} Further, the measured value of the scattered light signal has a lower crest value than the theoretical value of the scattered light signal. The peak value of the measured value becomes low because the particle size decreases due to the start of incandescence.

FIG. 11 is an example of a light receiving signal when the measurement target particle 202 is equal to or less than the maximum incandescent limit particle size. In FIG. 11, the measured value of the radiated light signal is represented by a thick line, and the scattered light signal is represented by a thin line. Further, the measured value of the scattered light signal is represented by a solid line, and the theoretical value of the scattered light signal is represented by a dotted line. The theoretical value of the scattered light signal excluding black carbon is represented by a alternate long and short dash line.

In FIG. 11, the amount of black carbon can be quantified by measuring _{I λ in the same manner as in the case of FIG.} Further, the measured value of the scattered light signal has a lower crest value than the theoretical value of the scattered light signal. The peak value of the measured value becomes low because the particle size decreases due to the start of incandescence. The measured value of the scattered light signal becomes a value close to the theoretical value of the scattered light signal excluding black carbon due to the start of incandescence.

FIG. 12 is an example of a light receiving signal when the particle 102 to be measured has a maximum incandescent limit particle size or more. In FIG. 12, the measured value of the radiated light signal is represented by a thick line, and the measured value of the scattered light signal is represented by a thin line.

FIG. 13 is an example of a light receiving signal when the particle 202 to be measured has a maximum incandescent limit particle size or more. In FIG. 13, the measured value of the radiated light signal is represented by a thick line, and the measured value of the scattered light signal is represented by a thin line. The case where the internal mixing ratio of the particle 202 to be measured is X% is represented by a solid line, the case where the internal mixing ratio is 100% is represented by a dotted line, and the case where the internal mixing ratio is 0% is represented by a alternate long and short dash line. When the internal mixing ratio is 100%, it is the same as the example of the received light signal shown in FIG.

In the radiated light signal, when the internal mixing ratio decreases, the crest value becomes low. Further, in the scattered light signal, when the internal mixing ratio decreases, the crest value increases. The internal mixing ratio can be estimated by calculating the ratio of the peak value of the scattered light signal.

FIG. 14 is a flowchart showing an example of a process in which the analysis unit 10 calculates the internal mixing ratio based on the measured peak value of the scattered light. The velocity detection unit 9 measures the moving velocity of the particle 2 to be measured (step S201). The analysis unit 10 calculates the theoretical scattering intensity when the internal mixing ratio is 100% and when the internal mixing ratio is 0%, based on the moving speed of the particle 2 to be measured (step S202). The analysis unit 10 compares the measured scattering intensity measured from the scattered light receiving element 8 with the theoretical scattering intensity (step S203). The analysis unit 10 calculates the internal mixing ratio from the comparison result (step S204).

FIG. 15 is a flowchart showing an example of a process in which the analysis unit 10 calculates the internal mixing ratio based on the measured radiant light. The velocity detection unit 9 measures the moving velocity of the particle 2 to be measured (step S301). The analysis unit 10 calculates the theoretical temperature when the internal mixing ratio is 100% based on the moving speed of the particle 2 to be measured (step 302). The analysis unit 10 compares the measured temperature measured from the radiant light receiving unit 20a and the radiant light receiving unit 20b with the theoretical temperature (step S303). The analysis unit 10 calculates the internal mixing ratio from the comparison result (step S304).

FIG. 16 is a diagram showing the relationship between the particle temperature and I _Blue / I _Red. As shown in FIG. 16, _{if the ratio of I Blue} and I _Red is known, the particle temperature can be measured. The measured temperature can be measured from the radiant light receiving unit 20a and the radiated light receiving unit 20b.

FIG. 17 is a diagram showing an example of the configuration of the speed detection unit 9. The speed detection unit 9 has a detection area 41, a difference calculation unit 51, and a calculation unit 61. The detection region 41 has two photoelectric conversion regions 42, a photoelectric conversion region 43, and a dead zone 44. The dead zone 44 is a dead zone sandwiched between two photoelectric conversion regions 42 and a photoelectric conversion region 43. The photoelectric conversion regions 42 and 43 convert light into an electric signal. The photoelectric conversion regions 42 and 43 may be avalanche photodiodes (APDs). In other words, the detection region 41 may be an APD element divided into two or more regions. On the other hand, the dead zone 44 does not convert light into an electrical signal. In one example, the detection region 41 is a region having photoelectric conversion regions 42 and 43 divided into at least two or more.

In this example, the dead zone 44 is a detection region for detecting that the spot image 45 of the measurement target particle 2 due to scattered light moves a predetermined distance on the light receiving surface. By acquiring the moving speed of the spot image 45 of the measurement target particle 2, the moving speed of the measurement target particle 2 can be obtained. The photoelectric conversion region 42, the dead zone 44, and the photoelectric conversion region 43 may be arranged in this arrangement order in the Y-axis direction. The dead zone 44 intersects the traveling direction of the spot image 45 of the measurement target particle 2. The width Δd of the dead zone 44 in the Y-axis direction may be 10 μm or more and 300 μm, and may be 100 μm or more and 300 μm.

The difference calculation unit 51 calculates the difference between the detection results in the two photoelectric conversion regions. In this example, the difference between the detection result in the photoelectric conversion region 42 and the detection result in the photoelectric conversion region 43 is calculated. The difference calculation unit 51 may include an IV conversion unit 52, an IV conversion unit 53, a non-inverting amplifier circuit 54, an inverting amplifier circuit 55, and an addition circuit 56. The IV conversion unit 52 converts a current corresponding to the light intensity of the scattered light received by one of the photoelectric conversion regions 42 into a voltage. The IV conversion unit 53 converts a current corresponding to the light intensity of the scattered light received by the other photoelectric conversion region 43 into a voltage.

The non-inverting amplifier circuit 54 does not invert one of the outputs of the IV conversion unit 52 and the IV conversion unit 53. The inverting amplifier circuit 55 inverts the other of the outputs of the IV conversion unit 52 and the IV conversion unit 53. The adder circuit 56 adds the outputs of the non-inverting amplifier circuit 54 and the inverting amplifier circuit 55. As a result, the difference calculation unit 51 calculates the difference between the detection results in the two photoelectric conversion regions 42 and 43. The calculated difference is output to the calculation unit 61. Common mode noise can be canceled by inverting one of the outputs of the IV conversion unit 52 and the IV conversion unit 53 and then adding the output. The calculation unit 61 calculates the moving speed of the measurement target particle 2 based on the output of the difference calculation unit 51. The calculation result of the moving speed is output to the analysis unit 10.

FIG. 18 is a diagram showing a method of calculating the moving speed of the measurement target particle 2 based on the output of the differential calculation unit 51. The output of the differential calculation unit 51 can be obtained by combining the output from the photoelectric conversion region 42 as positive and the output from the photoelectric conversion region 43 as negative. The output of the difference calculation unit 51 has a zero point due to the existence of the width Δd of the dead zone 44 in the Y-axis direction, which is the traveling direction of the spot image 45 of the particle 2 to be measured. If the scattered light of the particle 2 to be measured does not scale with respect to the light receiving surface and the optical system forms an image with the same size, the photoelectric conversion region 42 and the photoelectric conversion region 43 are divided by the dead zone 44. Then, the output of the difference calculation unit 51 is positive or negative when the spot image 45 of the measurement target particle 2 passes through the width Δd of the dead zone 44.

Further, assuming that the time required for the spot image 45 of the measurement target particle 2 to pass through the dead zone 44 is Δt, the calculation unit 61 calculates the equation V = Δd / Δt in the Y-axis direction of the measurement target particle 2. The moving speed V of is calculated. Δt is obtained from the output of the difference calculation unit 51. Specifically, the calculation unit 61 acquires Δt based on the time between the time of the negative peak and the time of the positive peak in the output of the difference calculation unit 51. In one example, the calculation unit 61 may calculate Δt by multiplying the time between the time of the negative peak and the time of the positive peak in the output of the difference calculation unit 51 by a constant k. The constant k is experimentally or theoretically predetermined. For example, assuming that k = 1, the calculation unit 61 sets Δt as the time between the negative peak time and the positive peak time in the output of the difference calculation unit 51.

Although the present invention has been described above using the embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It will be apparent to those skilled in the art that various changes or improvements can be made to the above embodiments.

The order of execution of operations, procedures, steps, steps, etc. in the devices, systems, programs, and methods shown in the claims, specification, and drawings is particularly "before" and "prior to". It should be noted that it can be realized in any order unless the output of the previous process is used in the subsequent process. Even if the scope of claims, the specification, and the operation flow in the drawings are explained using "first", "next", etc. for convenience, it means that it is essential to carry out in this order. It's not a thing.

1 ... Particle introduction nozzle, 2 ... Particles to be measured, 3 ... Laser light, 4 ... Objective lens, 5 ... Condensing lens, 6 ... Optical filter, 7 ... Radiant light receiving element, 8 ... Scattered light receiver, 9 ... Speed detector, 10 ... Analysis unit, 11 ... Optical filter, 12 ... Optical filter, 20 ... Radiant light receiver, 21 ... Central axis direction, 30 ... Scattered light Light receiving part, 40 ... laser irradiation part, 41 ... detection area, 42 ... photoelectric conversion area, 43 ... photoelectric conversion area, 44 ... dead zone, 45 ... spot image, 50 ... mirror, 51 ... difference Arithmetic unit, 52 ... IV conversion unit, 53 ... IV conversion unit, 54 ... non-inverting amplification circuit, 55 ... inverting amplification circuit, 56 ... addition circuit, 61 ... calculation unit, 100 ... particle analyzer , 102 ... Particles to be measured, 103 ... Substances to be measured, 202 ... Particles to be measured, 203 ... Substances to be measured, 204 ... Non-measurement target substances

Claims (15)

A particle analyzer that analyzes the substance to be measured by receiving the radiated light and scattered light emitted when the particle to be measured including the substance to be measured passes the laser beam.
A radiant light receiving unit that measures the light receiving intensity of the radiated light in at least two wavelength bands, and a radiant light receiving unit.
A scattered light receiving unit for measuring the light receiving intensity of the scattered light,
A first analysis that analyzes the amount of the substance to be measured from the radiated light according to the intensity ratio of the received intensity of the radiant light in the first wavelength band to the received intensity of the radiant light in the second wavelength band. A particle analyzer including an analysis unit that switches between analyzing in a mode and analyzing in a second analysis mode that analyzes the amount of the substance to be measured from the scattered light. The analysis unit analyzes in the first analysis mode when the intensity ratio is within the boiling point range including the value corresponding to the boiling point of the substance to be measured, and when the intensity ratio is outside the boiling point range. The particle analyzer according to claim 1, wherein the analysis is performed in the second analysis mode. The particle analyzer according to claim 1 or 2, wherein the analysis unit analyzes the amount of the substance to be measured based on the peak value of the light receiving intensity of the radiant light in the first analysis mode. The analysis unit calculates the amount of the measurement target substance from the size of the measurement target particle and the ratio of the measurement target substance to the measurement target particle in the second analysis mode according to claims 1 to 3. The particle analyzer according to any one item. The particle analyzer according to claim 4, wherein the analysis unit calculates the size of the measurement target particle based on the moving speed of the measurement target particle in the second analysis mode. In the second analysis mode, the analysis unit has a reference peak value which is a peak value of the scattered light when the ratio of the substance to be measured to the particles to be measured is a reference ratio, and the scattered light receiving unit. The particle analyzer according to claim 4 or 5, which calculates the ratio of the substance to be measured to the particles to be measured based on the measured peak value which is the peak value of the scattered light received. In the second analysis mode, the analysis unit receives the reference radiant light, which is the radiant light when the ratio of the substance to be measured to the measurement target particles is the reference ratio, and the radiant light receiving unit receives the light. The particle analyzer according to claim 4 or 5, which calculates the ratio of the substance to be measured to the particles to be measured based on the measured radiant light which is radiant light. In the second analysis mode, the analysis unit determines the ratio of the substance to be measured to the particles to be measured based on the reference temperature calculated from the reference radiation and the measurement temperature calculated from the measurement radiation. The particle analyzer according to claim 7, which is calculated. The particle analyzer according to any one of claims 1 to 8, wherein the analysis unit analyzes the amount of the substance to be measured from the time change of the light receiving intensity of the radiated light or the scattered light. At least one of the wavelength bands is a wavelength band equal to or higher than the peak wavelength of the substance to be measured at the boiling point temperature of the substance to be measured.
The particle analyzer according to any one of claims 1 to 9, wherein the at least one wavelength band is a wavelength band equal to or lower than the peak wavelength. The particle analyzer according to any one of claims 1 to 9, wherein at least two of the wavelength bands are wavelength bands equal to or higher than the peak wavelength of the substance to be measured at the boiling point temperature of the substance to be measured. The particle analyzer according to any one of claims 1 to 11, wherein the radiant light receiving unit sets at least one wavelength band according to the sensitivity of the light receiving intensity of the radiated light receiving unit. The radiant light receiving unit is
The light receiving intensity of the radiant light was measured in the three wavelength bands, and
The particle analyzer according to any one of claims 1 to 12, wherein the at least one wavelength band includes the peak wavelength of the non-measurement target substance at the boiling point temperature of the non-measurement target substance contained in the measurement target particle. The particle analyzer according to claim 13, wherein the non-measurement target substance is iron. The particle analyzer according to any one of claims 1 to 14, wherein the substance to be measured is black carbon.

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