KR102715411B1 - Apparatus and Method for High-Accuracy Optical Particle Measuring using Measurement Threshold Value Difference - Google Patents

Abstract

A high-precision optical particle measuring device according to the present invention comprises a light irradiation unit that irradiates a particle measuring laser into a particle measuring space, a detection unit that detects light scattered from particles in the particle measuring space, and a measurement unit that measures the number of particles using a signal detected by the detection unit. At this time, the measurement unit applies a measurement threshold value, which is set so that only particles of a corresponding size or larger for a plurality of different particle sizes, to the detection signal to measure the number of particles for each measurement threshold value, and uses the number of particles for each measurement threshold value and a conversion function experimentally determined in advance to distinguish and calculate the number of particles belonging to each particle size range. Since it is a method of simply applying the measurement threshold value in software, the number of particles for each size range can be measured more stably, can be implemented simply and conveniently, and can be processed at a faster speed because it utilizes the memory of a computer device.

Description

{ Apparatus and Method for High-Accuracy Optical Particle Measuring using Measurement Threshold Value Difference }

The present invention relates to a particle measuring device and a particle measuring method, and more specifically, to a method for measuring the number of particles in a size range with high accuracy without using additional components such as a flow nozzle or a flat-top optical system by utilizing the difference in a measurement threshold value for determining noise of a light detection signal.

Technology to measure the number of particles present in a specific space by dividing them into particle size ranges is in demand in various fields.

For example, processes that require high precision, such as semiconductor or display processes, are run under strictly limited conditions because if a certain level of contaminant particles are generated within the process chamber, it can lead to fatal product defects.

For contamination control, measurement of contaminant particles inside the chamber is required. As one method of contaminant particle measurement, the particle distribution status for a specific chamber or space can be measured in real time using an optical measurement device.

Optical particle measuring devices can use the principle of converting the intensity of scattered light generated when a laser strikes a particle into a size.

In general, the smaller the particle size, the smaller the intensity of scattered light, which can be calculated using Mie theory. Since the intensity of scattered light is proportional to the intensity of incident light, the intensity of incident light must be strong in order to measure small particles.

For this reason, in order to measure small particles, the laser must be focused.

Figure 1 shows that incident light (12) generated from a laser light source (11) passes through several optical components and is focused onto a flow channel (15). Here, the flow channel (15) is a space where target particles to be measured exist.

Referring to the following mathematical expression 1, in order to accurately measure particle size using the theory of the laser, the intensity (Io) of the incident light must be constant.

Here, I _{scat is} the intensity of scattered light, R is the distance from the point of scattered light generation to the detector, is a function of particle size.

At this time, the intensity of scattered light for particles of the same size may vary depending on which location in the focused incident light the particle passes through.

This is because the cross-section of light (21) is not uniform in the r-axis direction. For this reason, when the scattered light is converted into particle size, even if the same particle is measured, it may be recognized as a different size, and the optical particle measuring device cannot measure the exact size.

To solve the accuracy problem of particle size measurement, the following techniques have been used conventionally.

First, as in the example shown in Fig. 2, a method can be used to make particles pass through a specific location of incident light using a flow nozzle.

Using this method, since the particles pass only to the designated locations of the incident light, the intensity of the incident light becomes constant, making it possible to measure the exact size.

Most of the current pollutant particle measuring devices adopt this method. However, this method can be used under normal pressure (atmospheric pressure) conditions, but it is difficult to use in processes sensitive to pressure changes such as vacuum processes. In particular, it cannot be used in industrial sites that require a vacuum environment such as semiconductors and displays because it affects the process conditions. In addition, additional costs are required to create a flow nozzle, and the phenomenon of the flow nozzle being blocked by particles also occurs, making management difficult.

As another method, as shown in the example in FIG. 3, the patent registration number 10-1857950, “High-precision real-time fine particle size and count measuring device,” discloses a technology that enables more accurate particle size measurement by making the intensity of light uniform using a flat-top (17) module.

That is, in order to solve the problem of size measurement accuracy due to changes in the intensity of incident light, registered patent no. 10-1857950 uses a method of making the intensity of the incident light (12), which is a cross-section (22) of the light, in the r-axis direction uniform.

If an optical system (lens) is configured to make the incident light uniform, the intensity of the incident light in the r-axis direction can be made uniform, and the size of the scattered light does not change regardless of which location the particle passes.

However, particle measuring devices using this method have a very important optical system configuration, and since they must use aspherical optical systems, the manufacturing cost increases exponentially. In addition, since the intensity of the focused light is weaker than that of general focused light, there is a problem in that nano-sized particle measurement is impossible.

To solve this problem, Korean Patent No. 10-2227433 discloses a technology that can measure the number of particles by size range with high accuracy by using laser power scanning that sequentially irradiates lasers of various powers.

However, the above registered patent No. 10-2227433 has a disadvantage in that it is difficult to maintain the laser output at a constant level.

That is, the accuracy of particle count measurement may decrease as the laser output is sensitive to changes in environmental variables such as thermal aging and temperature.

In addition, since lasers of various powers must be examined sequentially, the complexity of the equipment increases and the problem of long measurement times may arise.

The national research and development projects related to this task are as follows.

Assignment ID: 22011100

Project Number: GP2022-0011-05

Government Department Name: Ministry of Science and ICT

Project Management Agency Name: Korea Research Institute of Standards and Science

Research Project Name: Development of Core Measurement Technology for Future Innovation Industries

Research Project Name: 3-1-04. Development of N-Lab Semiconductor Measurement Equipment Small and Medium Business Self-reliant Nuclear Technology

Contribution rate: 0.5

Project implementation organization name: Korea Research Institute of Standards and Science

Research period: 2022.01.01~2022.12.31

Assignment ID: 22011099

Project Number: GP2022-0011-04

Government Department Name: Ministry of Science and ICT

Project Management Agency Name: Korea Research Institute of Standards and Science

Research Project Name: Development of Core Measurement Technology for Future Innovation Industries

Research Project Name: 3-1-03. Development of Semiconductor Measurement Equipment Technology

Contribution rate: 0.5

Project implementation organization name: Korea Research Institute of Standards and Science

Research period: 2022.01.01~2022.12.31

(1) Republic of Korea Registered Patent No. 10-1857950 (Title: High-precision real-time fine particle size and number measuring device, Publication date: 2018.01.02) (2) Republic of Korea Patent No. 10-2227433 (Title: High-precision optical particle measuring device and particle measuring method using laser power scanning, Publication date: 2020.12.22)

Accordingly, the present invention has been made to solve the above problems, and the purpose of the present invention is to provide a highly accurate optical particle measurement device and method capable of measuring the number of particles by size range with high accuracy by utilizing the difference in the measurement threshold value for determining the noise of the optical detection signal rather than changing the power of the laser.

In order to achieve the above purpose, a high-precision optical particle measuring device using a difference in a measurement limit value according to the present invention may include a light irradiation unit that irradiates a first light for particle measurement into a particle measuring space; a detection unit that detects a second light affected by the first light from particles in the particle measuring space; and a measurement unit that measures the number of particles using a signal detected through the detection unit.

At this time, the measuring unit applies a measurement threshold value set to measure only particles larger than the corresponding size with respect to m different particle sizes (d1, d2, ..., dm) to the signal detected by the detection unit, and measures the number of particles for each measurement threshold value.

Using the number of particles for each of the above measurement limit values, the number of particles belonging to each particle size range Ri (when 'i < m', 'di ≤ Ri < d(i+1)', when 'i = m', 'Ri ≥ dm') can be calculated.

The first light may include a laser.

The second light may include light scattered from the particle, or light partially absorbed or extinguished by the particle.

The above measurement unit is a function of the experimentally determined measurement limit value, where ci is the number of particles belonging to the particle size range Ri to be calculated, Vk is the minimum measurement limit value that can measure particles of size dk, C[Vk] is the total number of particles measured by applying the measurement limit value Vk, and f(Vk) is the number of particles when the measurement limit value is Vk.

'c1, c2, ...,cm' can be configured to be calculated using 'f(V1)~f(Vm)' and 'C[V1]~C[Vm]'.

In addition, the above measuring part,

When ci[Vk] is the number of particles in the particle size range Ri measured by applying the measurement limit value Vk,

ci = ci[V1] + ci[V2] + ... + ci[Vm],

C[Vk] = c1[Vk] + c2[Vk] + ... + cm[Vk],

ci[Vk] = 0, (i < k),

ci[Vk] = ci[Vk], (i = k),

, (i > k)의 식을 이용하여,ci[Vk] =

, using the equation (i > k),

Each mathematical expression can be configured to produce 'c1, c2, ..., cm' through each mathematical expression transformed to include at least one of 'f(V1)~f(Vm)' and at least one of 'C[V1]~C[Vm]'.

The high-precision optical particle measuring device and method according to the present invention can calculate the number of particles by size range with high accuracy by analyzing a signal detected by a detector through each measurement limit value set corresponding to various particle sizes, rather than changing the power of a laser.

Therefore, the number of particles in a size range can be measured more stably, accuracy can be maintained, and implementation can be made simpler and more convenient than when changing the laser power.

Since it does not use additional components such as a flow nozzle or flat-top optical system, the development cost of the particle measuring device can be reduced, and it can be used regardless of whether it is in a normal pressure (atmospheric pressure) or vacuum environment.

Algorithms can be used to develop particle measurement devices with improved accuracy, and algorithm upgrades can also be used to improve accuracy in existing devices.

In particular, since the signal is processed by software rather than changing the detector, it does not place a burden on the physical circuit of the detector, and since it utilizes the memory of the computer device responsible for signal processing, it can be processed at a faster speed.

Figure 1 is an example illustrating the measurement of particles using light focusing.
Figure 2 is an example of using a flow nozzle for particle measurement.
Figure 3 is an example of a method for making the intensity of light in the r direction uniform.
Figure 4 is an embodiment of a high-precision optical particle measuring device according to the present invention.
Figure 5 is an example explaining the measurement threshold value for distinguishing noise.
Figure 6 is an example explaining how the measurement limit value is set according to the particle size.
Figure 7 is an example of an experimentally determined transformation function f(V).
Figure 8 is an example showing a comparison between the ci[Vk] value obtained through measurement and the value calculated using the conversion function f(V).
Figure 9 is an example comparing the particle size distribution of samples measured using the method according to the present invention and the SMPS, which is a reference device.
Figure 10 is an example of the experimental process for determining Ri, V, and f(V).
Figure 11 is an embodiment of a high-precision optical particle measurement method using a difference in measurement limit value according to the present invention.
Fig. 12 is another example of a high-precision optical particle measurement method using a difference in measurement limit value according to the present invention.

The present invention can be modified in various ways and has various embodiments, and specific embodiments are illustrated in the drawings and described in detail in the detailed description. However, this is not intended to limit the present invention to specific embodiments, but should be understood to include all modifications, equivalents, or substitutes included in the spirit and technical scope of the present invention.

In explaining the present invention, if it is determined that a detailed description of a related known technology may obscure the gist of the present invention, the detailed description is omitted.

The terminology used in this application is only used to describe specific embodiments and is not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly indicates otherwise.

In this application, it should be understood that terms such as “include” or “have” are intended to specify the presence of a feature, number, step, operation, component, part or combination thereof described in the specification, but do not exclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts or combinations thereof.

The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only to distinguish one component from another.

Referring to FIG. 4, a high-precision optical particle measuring device (100) according to the present invention comprises a light irradiation unit (110) that irradiates a first light for particle measurement into a particle measuring space (40), a detection unit (120) that detects second light affected by particles (30) present in the particle measuring space (40) from the first light irradiated through the light irradiation unit (110), and a measurement unit (130) that measures the number of particles using a signal detected through the detection unit (120).

The particle measurement space (40) refers to the measurement area where the target particles to be measured exist.

The light irradiation unit (110) can be configured in various ways to irradiate the first light to the particle measurement space (40).

The first light can be configured in various ways as needed, and a laser can be used as a specific example.

The second light may be a variety of light that can be used to measure particles, such as light scattered from the particle (30), light partially absorbed or extinguished by the particle (30), etc.

For convenience of explanation, in the following, the first light will be explained as an example of a laser, and the second light will be explained as an example of light scattered from a particle.

The detection unit (120) may be configured to include a detector that detects light scattered from particles existing in a particle measurement space by a laser irradiated through a light irradiation unit (110). The detector may be configured in various ways, and may use a photodiode (PD), an avalanche photodiode (APD), a photomuliplier tube (PMT), etc.

Figure 5 shows an example of a detector detection signal over time, and an example of a measurement limit value for distinguishing noise.

In order to measure the number of particles by analyzing the optical detection signal, it is necessary to set a measurement threshold value to determine the noise of the detector. Since the signal detected through the detector is generally expressed as voltage or current, the measurement threshold value can also be expressed as voltage or current.

However, the present invention is not limited thereto, and can be applied to any type of signal. In the following, for convenience of explanation, the measurement limit value is indicated by the voltage symbol V, but it can also be applied to current.

In Fig. 6, Vk(1≤k≤m) refers to the measurement limit value that can detect scattered light from particles with a particle size of dk or larger.

Assuming that a larger subscript number of d indicates a larger particle size, a larger subscript number of V may also lead to a larger absolute value of the measurement limit.

Figure 7 shows that as the absolute value of the measurement limit value decreases, particles of smaller size can be measured.

The measuring unit (130) calculates the number of particles belonging to each particle size range Ri by using the number of particles measured when each measurement limit value is applied.

Table 1 below shows definitions of symbols used in the description of the present invention. Hereinafter, an example of measuring the number of particles belonging to four particle size ranges (R1 to R4) will be described.

However, this is for convenience of explanation, and the number of particle size ranges in which each particle number is measured can be configured in various ways as needed.

Particle size range
(Ri) Number of particles
(ci) Measurement limit value
(V) ci[Vk] C[Vk] d1 ≤ R1 < d2 c1 V1 c1[V1], c1[V2], c1[V3], c1[V4] C[V1] d2 ≤ R2 < d3 c2 V2 c2[V1], c2[V2], c2[V3], c2[V4] C[V2] d3 ≤ R3 < d4 c3 V3 c3[V1], c3[V2], c3[V3], c3[V4] C[V3] d4 ≤ R4 c4 V4 c4[V1], c4[V2], c4[V3], c4[V4] C[V4]

di : particle size

Ri: Particle size range to be measured by distinguishing the number of particles

(when 'i < m', 'di ≤ Ri < d(i+1)', when 'i = m', 'Ri ≥ dm')

ci: The number of particles with a size corresponding to each particle size range Ri, which is the final value to be obtained.

Vk: The minimum measurement limit for measuring particles of minimum size dk in the particle size range Rk, which can be obtained through a calibration experiment that measures standard particle samples of only specific sizes.

ci[Vk]: Number of particles in the particle size range Ri measured using Vk.

C[Vk]: Total number of particles measured using Vk

Depending on the measurement limit, particles in each particle size range may or may not be measured.

For example, with respect to c1[V1], since the definition of V1 is the minimum measurement limit that can measure a particle of size d1, c1[V1] can be measured.

However, with respect to c1[V2], since the definition of V2 is the minimum measurement limit that can measure particles of size d2, particles of a size corresponding to the particle size range R1 cannot be measured. Therefore, 'c1[V2] = 0' holds true.

In particle size 'di', the smaller the subscript i, the smaller the particle, and the particle corresponding to dm is the largest size.

The number of particles ci corresponding to each particle size range Ri can be expressed by the mathematical expression 2 below.

Each item of the above mathematical expression 2 can be expressed as in the mathematical expression 3 below.

3) i > k, ci[Vk] =

As explained above, under the condition 'i < k', ci[Vk] = 0.

로 표현할 수 있다. Also, under the condition 'i >k', ci[Vk] =

can be expressed as

Here, f(V) is a function of the experimentally determined measurement limit, and is the number of particles when the measurement limit is V. That is, the 'f(Vk)/f(Vi)' value can be calculated through a calibration experiment that measures the number of particles according to the measurement limit.

Figure 7 shows the results of a particle count correction experiment for the measurement limit value and the results of regression analysis fitting. As a result of performing regression analysis on f(V) using two exponential functions, both functions were confirmed to have high accuracy with a coefficient of determination (R-square) of 99.95%.

In the example of Fig. 7, f(V) uses the exponential function of 'y = y0 + A×exp(R0×x)', 'y = a - b × c ^x ', but is not limited to this. Any function that can be expressed mathematically can be used, and the formula of the f(V) function can be inferred by performing regression analysis with a function with a high coefficient of determination.

을 증명하기 위하여, 교정 실험에서 실제 측정한 c4[V1], c4[V2], c4[V3] 값을, 회귀분석하여 얻어낸 f(V)를 이용하여 계산한

,

,

와 비교 검증한 결과이다.Figure 8 shows the equation ci[Vk] = when 'i >k'.

To prove this, the c4[V1], c4[V2], and c4[V3] values actually measured in the calibration experiment were calculated using f(V) obtained through regression analysis.

,

,

This is the result of comparative verification.

FIG. 9 shows a comparison of the particle size distribution measured according to the present invention (indicated as 'Algorithm') and the particle size distribution measured using a scanning mobility particle sizer (SMPS), which is a reference equipment, for each of two particle samples, for verification when using the measurement limit value.

The above mathematical expression 2 can be converted into the following mathematical expression 4 using mathematical expression 3.

However, when measuring a sample with an unknown size distribution, the total number of particles C[Vk] measured using a specific measurement limit can be obtained, but the number of particles corresponding to each particle size range cannot be distinguished.

Therefore, an additional process is required to convert the desired value, ci, into a function of C[Vk].

As defined in Table 1, C[Vk] is the total number of particles when measuring a measurement target sample with an unknown size distribution by applying the measurement limit value Vk. Therefore, C[Vk] can be expressed by the following mathematical expression 5.

The above mathematical expression 5 can be expressed as the following mathematical expression 6 using mathematical expression 3.

By substituting the above mathematical expression 6 into mathematical expression 4, the size distribution corresponding to each particle size range can be converted into a function of the actual measured value as in mathematical expression 7 below.

In this way, the number of particles ci corresponding to each particle size range Ri can be accurately measured only by using the C[Vk] value, which is the total number of particles measured by applying each set measurement limit value, and the conversion function f(V) obtained from the calibration experiment.

In order to calculate the number of particles ci corresponding to each particle size range Ri, the minimum detection limit for the minimum particle size di in each particle size range Ri and f(V), which is a function of the detection limit, must be experimentally determined.

Figure 10 shows an example of the process of experimentally obtaining Vk and f(V), first setting the particle size range Ri (S311).

The particle size range Ri can be set to various values as required.

For example, the particle size range can be set to four sections, and R1 to R4 can be set to '50 nm ≤ R1 < 100 nm', '100 nm ≤ R2 < 300 nm', '300 nm ≤ R3 < 700 nm', and '700 nm ≤ R4', respectively.

Then, a standard particle sample having only a size corresponding to di, which is the minimum size of each particle size range Ri, is prepared (S312).

In the above example, d1 = 50 nm, d2 = 100 nm, d3 = 300 nm, d4 = 700 nm.

Now, the minimum measurement limit (Vk) that can measure particles having a size di, which is the minimum size of each particle size range Ri, is confirmed through actual measurement (S313).

Then, the conversion function f(V) is calculated through a standard sample measurement experiment using each V value confirmed in step S313 (S314). An example of f(V) is shown in Fig. 7.

Steps S311 to S314 are experiments to determine parameters for accurately measuring the number of particles in each particle size range, and may have the meaning of a 'calibration experiment'.

FIG. 11 is a first embodiment of a high-precision optical particle measurement method using a difference in measurement limit values according to the present invention. After experimentally confirming the measurement limit values Vi and f(V) through a calibration experiment like the example shown in FIG. 10, the number of particles in each particle size range is measured for an actual measurement target sample whose size distribution is unknown.

First, the first light for particle measurement is irradiated to the particle measurement space for a certain period of time through the light irradiation unit (110) (S321, step 1).

The first light can be configured in various ways as needed, and a laser can be used as a specific example.

And, the detection unit (120) detects the second light that is affected by the first light irradiated through the light irradiation unit (110) from the particles in the particle measurement space (S322, second step).

The second light may be a variety of light that can be used to measure particles, such as light scattered from the particle (30), light partially absorbed or extinguished by the particle (30), etc.

Now, the measuring unit (130) analyzes the signal detected through the detection unit (120) to measure the number of particles for each particle size range Ri (third step).

The third step may be configured to include a process (S323) of measuring the number of particles for each measurement limit value by applying a measurement limit value set to measure only particles larger than the corresponding size to a signal detected through a detection unit (120) in relation to the minimum particle size of 'd1, d2, ..., dm' of each particle size range, and a process (S324) of calculating the number of particles belonging to each particle size range by using the number of particles for each measurement limit value.

The number of particles for each measurement limit value obtained in step S323 means the total number of particles (C[Vk]) measured when each measurement limit value is applied.

And, the measuring unit (130) can measure the number of particles ci for each particle size range Ri using the mathematical expression 7 in step S324.

That is, the measuring unit (130) can be configured to calculate 'c1, c2, ..., cm' through each mathematical expression converted to include at least one of 'f(V1)~f(Vm)' and at least one of 'C[V1]~C[Vm]'.

Meanwhile, a second embodiment of a high-precision optical particle measurement method using a difference in measurement limit value according to the present invention relates to a method in which a computer device calculates the number of particles belonging to each particle size range based on actual values detected from a detector.

Referring to FIG. 12, a second embodiment of a high-precision optical particle measurement method using a difference in measurement limit values according to the present invention comprises a measurement limit value application step (S331) and a calculation step (S332), and can be executed on a computer device.

Here, the computer device may be a variety of devices. For example, it may mean a measuring unit (130), or another computer device that can exchange data in conjunction with the detection unit (120) or the measuring unit (130).

An example of the latter is a manager computer device that provides various functions related to particle measurement according to the user's commands while providing various user interface (UI) screens.

First, by applying the measurement limit values set so that only particles larger than the corresponding size can be measured for m different particle sizes (d1, d2, ..., dm) to the analysis target signal, the number of particles (the number of particles by measurement limit value) when each measurement limit value is applied is measured (S331).

Here, the signal to be analyzed is a signal detected by a detector that detects light, and may be input in real time or may be data stored in a computer device.

Also, 'dl, ..., dm' are the minimum particle sizes in each of m particle size ranges Ri ('di ≤ Ri < d(i+1)' when 'i < m', 'Ri ≥ dm' when 'i = m').

The number of particles per measurement limit value measured in step S331 is the total number of particles (C[Vk]) when each measurement limit value Vk is applied to the signal detected through the detector.

Then, when the number of particles (C[Vk]) for each measurement limit value is measured, the number of particles ci for each particle size range Ri is distinguished and calculated using the mathematical expression 7 above (S332).

That is, the computer device can be configured to produce 'c1, c2, ..., cm' through each mathematical expression converted to include at least one of 'f(V1)~f(Vm)' and at least one of 'C[V1]~C[Vm]'.

In relation to the output step (S332), the computer device stores f(V), which is a function of the experimentally determined measurement limit value as the number of particles when the measurement limit value is V, or can receive it from an external device as needed.

Each embodiment of the high-precision optical particle measurement method using the difference in measurement limit value according to the present invention can be implemented as a computer-readable code on a computer-readable recording medium.

At this time, the computer-readable recording medium includes all types of recording devices that store data that can be read by a computer system. Examples include ROM, RAM, CD-ROM, magnetic tape, floppy disk, and optical data storage devices.

While the present invention has been illustrated and described above with respect to certain preferred embodiments, it will be apparent to those skilled in the art that the present invention may be variously modified and changed without departing from the technical characteristics or scope of the present invention as defined by the following claims.

30: particle
40: Particle measurement space
100: High-precision optical particle measuring device
110: Light irradiation unit
120: Detection section
130: Measuring section

Claims (11)

A light irradiation unit that irradiates the first light for particle measurement into the particle measurement space;
A detection unit for detecting second light influenced by particles in the particle measurement space by the first light; and
It includes a measuring unit that measures the number of particles using a signal detected through the above detection unit,
The above measurement unit applies a measurement threshold value set to measure only particles larger than the corresponding size for m different particle sizes (d1, d2, ..., dm) to the signal detected by the detection unit, and measures the number of particles for each measurement threshold value.
Using the number of particles for each of the above measurement limit values, the number of particles belonging to each particle size range Ri (when 'i <m','di ≤ Ri <d(i+1)', when 'i = m', 'Ri ≥ dm') is calculated.
When ci is the number of particles belonging to the particle size range Ri that is to be calculated, Vk is the minimum measurement limit that can measure particles of size dk, C[Vk] is the total number of particles measured by applying the measurement limit Vk, and f(Vk) is the number of particles when the measurement limit is Vk, which is a function of the experimentally determined measurement limit.
A high-precision optical particle measuring device that utilizes the difference in measurement limit values to calculate 'c1, c2, ..., cm' using 'f(V1)~f(Vm)' and 'C[V1]~C[Vm]'. In the first paragraph,
The above first light comprises a laser,
A high-precision optical particle measuring device utilizing the difference in measurement limit value, wherein the second light includes light scattered from the particle, or light partially absorbed or extinguished by the particle. delete In the first paragraph,
The above measuring part,
When ci[Vk] is the number of particles in the particle size range Ri measured by applying the measurement limit value Vk,
ci = ci[V1] + ci[V2] + ... + ci[Vm],
C[Vk] = c1[Vk] + c2[Vk] + ... + cm[Vk],
ci[Vk] = 0, (i < k),
ci[Vk] = ci[Vk], (i = k),
ci[Vk] =

, using the equation (i > k),
A high-precision optical particle measuring device utilizing the difference in measurement limit values to calculate 'c1, c2, ..., cm' through each mathematical expression converted to include at least one of 'f(V1)~f(Vm)' and at least one of 'C[V1]~C[Vm]'. A first step in which a light irradiation unit irradiates a first light for particle measurement into a particle measurement space;
A second step in which the detection unit detects the second light affected by the first light from the particles in the particle measurement space; and
The measuring unit includes a third step of measuring the number of particles belonging to each of m particle size ranges Ri ('di ≤ Ri <d(i+1)' when 'i <m','Ri ≥ dm' when 'i = m') using the signal detected by the detection unit,
The third step above is,
Regarding the minimum particle size of each particle size range above, 'd1, d2, ..., dm', a measurement threshold value set to measure only particles larger than the corresponding size is applied to the signal detected through the detection unit, and the number of particles for each measurement threshold value is measured.
Using the number of particles for each of the above measurement limits, the number of particles belonging to each particle size range is calculated.
When ci is the number of particles in the particle size range Ri that is to be produced, Vk is the minimum measurement limit that can measure particles of size dk, C[Vk] is the total number of particles measured by applying the measurement limit Vk, and f(Vk) is the number of particles when the measurement limit is Vk, which is a function of the experimentally determined measurement limit,
A high-precision optical particle measurement method using the difference in measurement limit values, configured to calculate 'c1, c2, ..., cm' using 'f(V1)~f(Vm)' and 'C[V1]~C[Vm]'. In paragraph 5,
The above first light comprises a laser,
A high-precision optical particle measurement method using a difference in measurement limit value, wherein the second light includes light scattered from the particle, or light partially absorbed or extinguished by the particle. delete In paragraph 5,
The above measuring part,
When ci[Vk] is the number of particles in the particle size range Ri measured by applying the measurement limit value Vk,
ci = ci[V1] + ci[V2] + ... + ci[Vm],
C[Vk] = c1[Vk] + c2[Vk] + ... + cm[Vk],
ci[Vk] = 0, (i < k),
ci[Vk] = ci[Vk], (i = k),
ci[Vk] =

, using the equation (i > k),
A high-precision optical particle measurement method utilizing the difference in measurement limit values, which calculates 'c1, c2, ..., cm' through each mathematical expression converted to include at least one of 'f(V1)~f(Vm)' and at least one of 'C[V1]~C[Vm]'. A measurement limit value application step for measuring the number of particles (the number of particles by measurement limit value) when each measurement limit value is applied by applying a measurement limit value set so that only particles larger than the corresponding size can be measured to the analysis target signal with respect to m (m is an integer greater than or equal to 2) different particle sizes (d1, d2, ..., dm) - the analysis target signal is a signal detected through a detector that detects light, and 'dl, ..., dm' is the minimum particle size in each of the m particle size ranges -; and
A calculation step is included for calculating the number of particles belonging to each particle size range Ri (when 'i <m','di ≤ Ri <d(i+1)', when 'i = m', 'Ri ≥ dm') using the number of particles for each of the above measurement limit values,
The above production steps are:
When ci is the number of particles in the particle size range Ri that is to be produced, Vk is the minimum measurement limit that can measure particles of size dk, C[Vk] is the total number of particles measured by applying the measurement limit Vk, and f(Vk) is the number of particles when the measurement limit is Vk, which is a function of the experimentally determined measurement limit.
A high-precision optical particle measurement method using the difference in measurement limit values, which calculates 'c1, c2, ..., cm' using 'f(V1)~f(Vm)' and 'C[V1]~C[Vm]'. In Article 9,
The above production steps are:
When ci[Vk] is the number of particles in the particle size range Ri measured by applying the measurement limit value Vk,
ci = ci[V1] + ci[V2] + ... + ci[Vm],
C[Vk] = c1[Vk] + c2[Vk] + ... + cm[Vk],
ci[Vk] = 0, (i < k),
ci[Vk] = ci[Vk], (i = k),
ci[Vk] =

, using the equation (i > k),
A high-precision optical particle measurement method using the difference in measurement limit values, configured to calculate 'c1, c2, ..., cm' through each mathematical expression converted to include at least one of 'f(V1)~f(Vm)' and at least one of 'C[V1]~C[Vm]'. A computer-readable recording medium having recorded thereon a program for executing a high-precision optical particle measurement method using the difference in the measurement limit value described in claim 9 or claim 10 on a computer.

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