Particle size distribution measuring device and method for determining diffusion state of particles in sample

Abstract

To mitigate the time and effort of a user in the work of confirming the diffused state of particles in a sample.SOLUTION: A particle size distribution measuring device 100 irradiates a sample SP with light from a light source 11 and measures the particle size distribution DP of particles in a sample SP on the basis of a light intensity distribution DL obtained by receiving light diffracted and scattered by the sample SP with a plurality of light receiving elements 171. The particle size distribution measuring device 100 comprises: a generation unit 512 that generates an index PR for determining the diffused state of particles in the sample SP on the basis of a light intensity distribution DL in an N-th period and a light intensity distribution DL in a (N+1)th period following the N-th period; and a determination unit 513 that determines on the basis of the index PR whether or not the diffusion state of particles in the sample SP has stabilized.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a particle size distribution measuring device and a method for determining the diffusion state of a particle group in a sample. [Background technology]

[0002] Conventionally, various techniques for reducing the workload of an operator in a particle size distribution measuring device have been known. For example, Patent Document 1 discloses a particle size distribution measuring device that is equipped with multiple measurement cells, and that can reduce the burden on the user by enabling analysis design without considering the physical arrangement of each measurement cell when the user wants to perform measurements using the cells in the order desired. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-163942 Summary of the Invention [Problem to be solved by the invention]

[0004] However, particle size distribution analyzers cannot begin analysis simply by placing particles in a measurement cell. Even if a measurement cell is used, analysis cannot begin until the analysis preparation is complete. For example, one step in the analysis preparation is to wait until the particle scattering state stabilizes. The sample to be measured may be solidified immediately after being placed in the analyzer. If the sample is analyzed while still solidified, erroneous analysis results will be obtained, and the desired analytical data will not be obtained. Furthermore, even if a user understands the importance of stabilizing the scattering state, determining whether the scattering state has stabilized is often done visually, requiring the user to have extensive knowledge.

[0005] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a particle size distribution measuring device that can reduce the user's effort in checking the diffusion state of a particle group in a sample, and a method for determining the diffusion state of a particle group in a sample. [Means for solving the problem]

[0006] A particle size distribution measuring device according to a first aspect of the present invention is a particle size distribution measuring device that measures the particle size distribution of a particle group in the sample based on a light intensity distribution obtained by irradiating a sample with light from a light source and receiving the light diffracted and scattered by the sample with a plurality of light receiving elements, and includes: a generation unit that generates an index for determining a diffusion state of the particle group in the sample based on the light intensity distribution in a first period and the light intensity distribution in a second period after the first period; and a determination unit that determines whether the diffusion state of the particle group in the sample has stabilized based on the index.

[0007] A method for determining the diffusion state of a particle group in a sample according to a second aspect of the present invention is a method for determining the diffusion state of a particle group in a particle size distribution measuring device that measures the particle size distribution of a particle group in the sample based on a light intensity distribution obtained by irradiating light onto the sample from a light source and receiving light diffracted and scattered by the sample with a plurality of light receiving elements, the method including: generating an index for determining the diffusion state of the particle group in the sample based on the light intensity distribution in a first period and the light intensity distribution in a second period after the first period; and determining whether the diffusion state of the particle group in the sample has stabilized based on the index. [Effects of the Invention]

[0008] A particle size distribution measuring device according to a first aspect of the present invention and a method for determining a diffusion state of a particle group in a sample according to a second aspect of the present invention generate an index for determining the diffusion state of the particle group in the sample based on a light intensity distribution in a first period and a light intensity distribution in a second period after the first period, and determine whether the diffusion state of the particle group in the sample has stabilized based on the index. Therefore, it is possible to properly generate an index for determining the diffusion state of the particle group in the sample. Furthermore, since it is determined whether the diffusion state of the particle group in the sample has stabilized based on the index, it is possible to properly determine whether the diffusion state of the particle group in the sample has stabilized. Therefore, it is possible to reduce the user's effort in checking the diffusion state of the particle group in the sample. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a diagram illustrating an example of the configuration of a particle size distribution measuring device according to an embodiment of the present invention. [Figure 2] FIG. 2 illustrates an example of the configuration of a control unit. [Figure 3] 10 is a graph showing an example of a light intensity distribution in a first period. [Figure 4] 10 is a graph showing an example of a change in an index. [Figure 5] 10 is a flowchart illustrating an example of processing by a control unit. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, this embodiment will be described with reference to the drawings.

[0011] [1. Configuration of particle size distribution measuring device] FIG. 1 is a diagram showing an example of the configuration of a particle size distribution measuring device 100 according to this embodiment. The particle size distribution measuring device 100 of this embodiment irradiates light from a light source 11 onto a sample SP, and measures the particle size distribution DP of a particle group in the sample SP based on a light intensity distribution DL obtained by receiving the light diffracted and scattered by the sample SP with a detector 17. As shown in FIG. 1, the particle size distribution measuring device 100 includes a measuring mechanism 1, a sample supplying mechanism 2, an A / D converter 3, a control unit 5, an operating mechanism 61, and a display mechanism 62.

[0012] The measurement mechanism 1 includes a light source 11, a condenser lens 12, a spatial filter 13, a collimator lens 14, a flow cell 15, a condenser lens 16, and a detector 17. A sample SP to be measured is supplied to the flow cell 15 from, for example, a sample supply mechanism 2. The sample SP is a liquid sample in which a particle group is dispersed.

[0013] The sample supply mechanism 2 is a mechanism that sends a predetermined amount of sample SP to the flow cell 15 per unit time, and includes, for example, a liquid feed pump. In this embodiment, for example, an inlet pipe extending from a storage container that stores the sample SP is connected to an inlet of the flow cell 15. Also, for example, one end of a discharge pipe is connected to an outlet of the flow cell 15, and the other end of the discharge pipe is connected to a storage container. By operating the liquid feed pump, the sample SP in the storage container flows from the inlet into the flow cell 15. Then, the sample SP is discharged from the outlet of the flow cell 15 via the discharge pipe into the storage container. In this way, the sample SP is circulated between the storage container and the flow cell 15. Note that, in order to stabilize the scattering state of the sample SP, which will be described later, the sample SP may be circulated within the device before the start of analysis. Furthermore, for example, an ultrasonic vibrator may be placed in the storage container of the sample supply mechanism 2, and ultrasonic vibrations may be used to promote stabilization of the scattering state of the sample SP.

[0014] The light source 11 is, for example, a laser light source. Light (measurement light) emitted from the light source 11 becomes parallel light by passing through a condenser lens 12, a spatial filter 13, and a collimator lens 14 in this order. The measurement light thus made parallel is irradiated onto a flow cell 15 in which a sample SP is supplied. Light diffracted and scattered by the particle group contained in the sample SP in the flow cell 15 (diffracted and scattered light) passes through a condenser lens 16 and is received by a detector 17.

[0015] The detector 17 detects the intensity of diffracted / scattered light from the sample SP. The detector 17 has, for example, a plurality of (e.g., 73) light receiving elements 171. The light receiving elements 171 are, for example, photodiodes. The plurality of light receiving elements 171 are arranged on, for example, a detection surface having a disk shape or a partial disk shape (e.g., a semi-disc shape). The plurality of light receiving elements 171 are arranged on the detection surface, for example, in a concentric pattern with the optical axis of the condenser lens 16 as the center. Light from the sample SP is incident on each of the plurality of light receiving elements 171 at an incident angle θ corresponding to the position on the detection surface. Therefore, the detection signal of each of the plurality of light receiving elements 171 represents the intensity of light corresponding to the incident angle θ.

[0016] 1, the detector 17 is disposed in the traveling direction of the measurement light (opposite to the light source 1) with respect to the flow cell 15. Note that the detector 17 may also include a light receiving element on at least one of the opposite side of the traveling direction of the measurement light (i.e., the light source 11 side) and the side (in a plane intersecting the traveling direction of the measurement light) with respect to the flow cell 15.

[0017] The detection signals of the plurality of light receiving elements 171 arranged in the detector 17 are input to the A / D converter 3. The A / D converter 3 converts the input analog signals into digital signals. The digital signals converted by the A / D converter 3 are input to the control unit 5. The control unit 5 acquires the light intensity at each of the plurality of light receiving elements 171 arranged in the detector 17 in association with the element number of each of the plurality of light receiving elements 171.

[0018] The control unit 5 is connected to an operation mechanism 61 and a display mechanism 62 so as to be able to communicate with each other. The operation mechanism 61 includes, for example, a keyboard, a mouse, etc., and receives operations from a user. The operation mechanism 61 also generates an operation signal corresponding to the received operation and outputs the generated operation signal to the control unit 5. The display mechanism 62 includes a display such as an LCD (Liquid Crystal Display), and displays various images on the display in accordance with instructions from the control unit 5.

[0019] [2. Control Unit Configuration] Next, the configuration of the control unit 5 will be described with reference to Fig. 2. Fig. 2 is a diagram showing an example of the configuration of the control unit 5. The control unit 5 is configured by, for example, a personal computer. The control unit 5 includes a processor 51 and a memory 52. The processor 51 includes a CPU (Central Processing Unit), an MPU (Micro-Processing Unit), and the like. The memory 52 is configured by a ROM (Read Only Memory), a RAM (Random Access Memory), etc. The memory 52 stores a control program 521.

[0020] The control unit 5 is not limited to a personal computer, and may be configured by one or more appropriate circuits such as an integrated circuit, such as an IC chip or an LSI. The control unit 5 may also be configured by, for example, a tablet terminal, a smartphone, or the like. The control unit 5 may also include programmed hardware such as a DSP (Digital Signal Processor) or an FPGA (Field Programmable Gate Array). The main body control device 50 may also include an SoC (System-on-a-Chip)-FPGA.

[0021] As shown in FIG. 2, the control unit 5 includes an acquisition unit 511, a generation unit 512, a determination unit 513, a measurement execution unit 514, and a standard deviation storage unit 522. Specifically, the processor 51 executes a control program 521 stored in the memory 52, thereby functioning as an acquisition unit 511, a generation unit 512, a determination unit 513, and a measurement execution unit 514. In addition, the processor 51 executes the control program 521 stored in the memory 52, thereby causing the memory 52 to function as a standard deviation storage unit 522.

[0022] The standard deviation storage unit 522 stores the standard deviation of the light intensity detected by the specified light receiving element 171A in the Nth period. The integer N is an integer equal to or greater than 1 and equal to or less than the integer M. The integer M is, for example, "8." Each of the Nth periods (N=1 to M) lasts, for example, 3 to 5 seconds. The specific light receiving element 171A is, for example, an element with element number 3. The standard deviation of the light intensity detected by the specific light receiving element 171A in the Nth period (N=1 to M) is stored in the standard deviation storage unit 522 by the generation unit 512.

[0023] The acquiring unit 511 acquires the light intensity of each of the plurality of light receiving elements 171 in association with the element number of each of the plurality of light receiving elements 171 arranged in the detector 17. The element number assigned to a corresponding light receiving element 171 is smaller as the element is arranged closer to the optical axis of the condenser lens 16. In this embodiment, the element numbers are, for example, "1" to "73". The specific light receiving element 171A is, for example, an element with an element number of "3", and is therefore an element that is disposed near the optical axis of the condenser lens 16.

[0024] The generation unit 512 generates an index PR for determining the diffusion state of the particle group in the sample SP based on the light intensity distribution DL in the Nth period and the light intensity distribution DL in the (N+1)th period after the Nth period. The integer N is an integer equal to or greater than 1 and equal to or less than the integer M. The generating unit 512 generates, for example, the difference between the Nth standard deviation and the (N+1)th standard deviation as the index PR. The Nth standard deviation is the standard deviation of the light intensity detected by the specific light receiving element 171A in the Nth period. The (N+1)th standard deviation is the standard deviation of the light intensity detected by the specific light receiving element 171A in the (N+1)th period. The Nth period corresponds to an example of a "first period." The (N+1)th period corresponds to an example of a "second period."

[0025] The determination unit 513 determines whether the diffusion state of the particle group in the sample SP has stabilized based on the index PR. For example, when the index PR is equal to or less than a preset threshold value TH, the determination unit 513 determines that the diffusion state of the particle group in the sample SP has stabilized. The threshold value TH is, for example, 0.5%. The light intensity detected by the light receiving element 171 is calculated as 0 to 100%. The threshold TH is further explained with reference to FIG. When the light intensity detected by the light receiving element 171 is "100%,", it indicates, for example, that the light intensity detected by the light receiving element 171 is maximum. The maximum intensity indicates, for example, the maximum light intensity that the light receiving element 171 can detect. When the light intensity detected by the light receiving element 171 is "0%,", it indicates that no light is detected by the light receiving element 171.

[0026] When the determination unit 513 determines that the diffusion state of the particle group in the sample SP has stabilized, the determination unit 513 causes the display mechanism 62 to display an image indicating that the diffusion state of the particle group in the sample SP has stabilized. The determination unit 513 causes the display mechanism 62 to display, for example, a text image stating "The diffusion state of the particle group in the sample has stabilized. Please start measuring the particle size distribution."

[0027] When the determination unit 513 determines that the diffusion state of the particle group in the sample SP has stabilized, the measurement execution unit 514 starts measuring the particle diameter distribution DP based on the light intensity distribution DL. The light intensity distribution DL indicates the distribution of light intensity obtained by receiving light with the multiple light receiving elements 171 arranged in the detector 17. The particle diameter distribution DP indicates the distribution of particle diameters of the particle group in the sample SP. The light intensity distribution DL will be further explained with reference to FIG.

[0028] Next, the light intensity distribution DL will be described with reference to Fig. 3. Fig. 3 is a graph showing an example of the light intensity distribution DL in the first period in which the integer N is 1. In the graph 700 shown in FIG. 3, the horizontal axis represents the element number and the vertical axis represents the light intensity (%). Graph G1 shows the light intensity (%) corresponding to the element number. As shown in graph G1, the light intensity of the specific light receiving element 171A is greater than the light intensity of the other light receiving elements 171. The specific light receiving element 171A is the element with the element number "3." As shown in FIG. 3, the light receiving element 171 having the maximum light intensity in the first period may be selected as the specific light receiving element 171A.

[0029] Next, a change in the index PR will be described with reference to Fig. 4. Fig. 4 is a graph showing an example of a change in the index PR. In the graph diagram 710 shown in FIG. 4, the horizontal axis represents the period number (N+1), and the vertical axis represents the index PR. The period number (N+1) means that the generation unit 512 calculates, as the index PR, the difference between the Nth standard deviation and the (N+1)th standard deviation. That is, when the period number (N+1) is "2," the generation unit 512 calculates, as the index PR, the difference between the first standard deviation and the second standard deviation. Furthermore, when the period number (N+1) is "3," the generation unit 512 calculates, as the index PR, the difference between the second standard deviation and the third standard deviation.

[0030] Graph G2 shown in FIG. 4 shows the relationship between the index PR and the period number (N+1). As shown in graph G2, the value of the index PR decreases as the period number (N+1) increases. Then, when the period number (N+1) is "7", the index PR becomes equal to or less than the threshold value TH. That is, the value of the index PR generated by the generation unit 512 becomes equal to or less than the threshold value TH when the period number (N+1) is "7". That is, when the generation unit 512 calculates the value of the index PR corresponding to the period number (N+1) of "7", the determination unit 513 determines that the diffusion state of the particle group in the sample SP has stabilized. Note that when the period number (N+1) is "7", the generation unit 512 calculates the difference between the sixth standard deviation and the seventh standard deviation as the index PR.

[0031] [3. Processing of control unit] Next, the processing executed by the control unit 5 will be described with reference to Fig. 5. Fig. 5 is a flowchart showing an example of the processing executed by the control unit 5. As shown in FIG. 5, first, in step S101, the control unit 5 sets an integer N to "1." Next, in step S103, the acquisition unit 511 acquires the light intensity distribution DL in the Nth period. Next, in step S105, the generating unit 512 calculates the Nth standard deviation, which is the standard deviation of the light intensity detected by the specific light receiving element 171A in the Nth period.

[0032] Next, in step S107, the acquisition unit 511 acquires the light intensity distribution DL in the (N+1)th period. Next, in step S109, the generating unit 512 calculates the (N+1)th standard deviation. The (N+1)th standard deviation is the standard deviation of the light intensity detected by the specific light receiving element 171A in the (N+1)th period. Next, in step S111, the generating unit 512 calculates the index PR, which is the difference between the Nth standard deviation and the (N+1)th standard deviation.

[0033] Next, in step S113, the determination unit 513 determines whether the index PR is equal to or less than the threshold value TH. If the determining unit 513 determines that the index PR is equal to or less than the threshold value TH (step S113; YES), the process proceeds to step S115. Then, in step S115, the determination unit 513 determines that the diffusion state of the particle group in the sample SP has stabilized, and displays an image indicating that the diffusion state of the particle group in the sample SP has stabilized on the display mechanism 62. Thereafter, the process ends.

[0034] If the determining unit 513 determines that the index PR is not equal to or less than the threshold value TH (step S113; NO), the process proceeds to step S117. Then, in step S117, the determining unit 513 determines that the diffusion state of the particle group in the sample SP is not stable. Next, in step S119, the control unit 5 increments the integer N by "1", and the process returns to step S107.

[0035] Step S111 corresponds to an example of a "generation step." Steps S113 to S117 correspond to an example of a "determination step."

[0036] [4. Aspects and Effects] It will be understood by those skilled in the art that the above-described embodiment is a specific example of the following aspects.

[0037] (Section 1) The particle size distribution measuring device according to this embodiment is a particle size distribution measuring device that measures the particle size distribution of a particle group in the sample based on a light intensity distribution obtained by irradiating a sample with light from a light source and receiving the light diffracted and scattered by the sample with a plurality of light receiving elements, and includes: a generation unit that generates an index for determining a diffusion state of the particle group in the sample based on the light intensity distribution in a first period and the light intensity distribution in a second period that is later than the first period; and a determination unit that determines whether the diffusion state of the particle group in the sample has stabilized based on the index.

[0038] According to the particle size distribution measuring device described in paragraph 1, an index for determining the diffusion state of the particle group in the sample is generated based on the light intensity distribution in a first period and the light intensity distribution in a second period after the first period, and it is determined whether the diffusion state of the particle group in the sample has stabilized based on the index. Therefore, it is possible to properly generate an index for determining the diffusion state of the particle group in the sample. Furthermore, since it is determined whether the diffusion state of the particle group in the sample has stabilized based on the index, it is possible to properly determine whether the diffusion state of the particle group in the sample has stabilized. Therefore, it is possible to reduce the user's effort in checking the diffusion state of the particle group in the sample.

[0039] (Section 2) The particle size distribution measuring device according to claim 1 further comprises a measurement execution unit that starts measuring the particle size distribution based on the light intensity distribution when the determination unit determines that the diffusion state of the particle group in the sample has stabilized.

[0040] According to the particle size distribution measuring device described in item 2, when it is determined that the diffusion state of the particle group in the sample has stabilized, measurement of the particle size distribution is started based on the light intensity distribution. Therefore, the measurement of particle size distribution can be started at an appropriate timing, and therefore the measurement of particle size distribution can be carried out efficiently and appropriately.

[0041] (Section 3) In the particle size distribution measuring device described in paragraph 1 or 2, the generation unit generates, as the index, a difference between a first standard deviation, which is the standard deviation of the light intensity during the first period, detected by a specific light-receiving element, which is at least one predetermined light-receiving element among the plurality of light-receiving elements, and a second standard deviation, which is the standard deviation of the light intensity during the second period, detected by the specific light-receiving element.

[0042] According to the particle size distribution measuring device described in paragraph 3, the difference between a first standard deviation, which is the standard deviation of the light intensity detected by the specific light-receiving element in the first period, and a second standard deviation, which is the standard deviation of the light intensity detected by the specific light-receiving element in the second period, is generated as the index. Therefore, an index for determining the diffusion state of the particle group in the sample can be generated appropriately, and therefore, it can be determined appropriately whether the diffusion state of the particle group in the sample is stable.

[0043] (Section 4) In the particle size distribution measuring device described in paragraph 1 or 2, the generation unit generates, as the index, a difference between a first difference, which is a difference between a maximum value and a minimum value of the light intensity during the first period, detected by a specific light-receiving element, which is at least one predetermined light-receiving element among the plurality of light-receiving elements, and a second difference, which is a difference between a maximum value and a minimum value of the light intensity during the second period, detected by the specific light-receiving element.

[0044] According to the particle size distribution measuring device described in item 4, the index is generated as a difference between a first difference, which is the difference between the maximum and minimum values of the light intensity detected by the specific light-receiving element in the first period, and a second difference, which is the difference between the maximum and minimum values of the light intensity detected by the specific light-receiving element in the second period. Therefore, an index for determining the diffusion state of the particle group in the sample can be generated appropriately, and therefore, it can be determined appropriately whether the diffusion state of the particle group in the sample is stable.

[0045] (Section 5) In the particle size distribution measuring device described in item 3, the specific light receiving element is a light receiving element of the plurality of light receiving elements whose incident angle is equal to or smaller than a preset first angle.

[0046] According to the particle size distribution measuring device described in item 5, the specific light receiving element is a light receiving element of the plurality of light receiving elements whose incident angle is equal to or smaller than a preset first angle. Therefore, by setting the first angle to an appropriate value, an appropriate light receiving element can be set as the specific light receiving element, and therefore an index for determining the diffusion state of the particle group in the sample can be generated appropriately.

[0047] (Section 6) In the particle size distribution measuring device described in item 3, the determining unit determines that the diffusion state of the particle group in the sample is stable when the difference between the first standard deviation and the second standard deviation is equal to or less than a preset threshold value.

[0048] According to the particle size distribution measuring device described in item 6, when the difference between the first standard deviation and the second standard deviation is equal to or less than a preset threshold, it is determined that the diffusion state of the particle group in the sample is stable. Therefore, it is possible to properly determine whether the diffusion state of the particle group in the sample has stabilized with a simple configuration, thereby reducing the user's effort in checking the diffusion state of the particle group in the sample.

[0049] (Section 7) The method for determining the diffusion state of a particle group in a sample according to this embodiment is a method for determining the diffusion state of a particle group in a particle size distribution measuring device that measures the particle size distribution of a particle group in the sample based on a light intensity distribution obtained by irradiating light onto the sample from a light source and receiving light diffracted and scattered by the sample with a plurality of light-receiving elements, and includes a generation step of generating an index for determining the diffusion state of the particle group in the sample based on the light intensity distribution in a first period and the light intensity distribution in a second period after the first period, and a determination step of determining whether the diffusion state of the particle group in the sample has stabilized based on the index.

[0050] According to the method for determining the diffusion state of a particle group in a sample described in item 7, the same effects as those of the particle size distribution measuring device described in item 1 are achieved.

[0051] [5. Other embodiments] The particle size distribution measuring device 100 according to this embodiment is merely an example of an aspect of the particle size distribution measuring device according to the present invention, and can be modified and applied as desired within the scope of the gist of the present invention.

[0052] For example, in this embodiment, a case will be described in which the specific light receiving element 171A is the light receiving element 171 with the element number "3", but the embodiment is not limited to this. The specific light receiving element 171A may be at least one light receiving element 171 among the multiple light receiving elements 171 arranged in the detector 17. The specific light receiving element 171A may be, for example, two light receiving elements 171 or three light receiving elements 171. It is preferable that the specific light receiving element 171A is a light receiving element 171 whose incident angle θ is equal to or less than a preset first angle θ1. The first angle θ1 is, for example, 5 degrees. The incident angle θ is the angle between the optical axis of the condenser lens 16 and the light ray received by the light receiving element 171.

[0053] In this embodiment, a case will be described in which the index PR is the difference between the Nth standard deviation and the (N+1)th standard deviation, but the embodiment is not limited to this. The index PR may be, for example, the difference between the Nth difference (N=1 to M) and the (N+1)th difference. The Nth difference is the difference between the maximum and minimum values of the light intensity detected by the specific light receiving element 171A in the Nth period. The integer N is an integer equal to or greater than 1 and equal to or less than the integer M. The (N+1)th difference is the difference between the maximum and minimum values of the light intensity detected by the specific light receiving element 171A in the (N+1)th period.

[0054] 2 indicates a functional configuration, and the specific implementation form is not particularly limited. In other words, it is not necessary to implement hardware corresponding to each functional unit individually, and it is of course possible to implement a configuration in which a single processor executes a program to realize the functions of multiple functional units. Furthermore, some of the functions realized by software in the above embodiments may be realized by hardware, or some of the functions realized by hardware may be realized by software.

[0055] 5 are divided according to the main processing content in order to facilitate understanding of the processing of the control unit 5. The division method and names of the processing units shown in the flowchart of FIG. 5 are not limiting, and the processing can be divided into more processing units according to the processing content, or one processing unit can be divided to include more processes. The processing order of the above flowchart is also not limited to the example shown in the figure.

[0056] 2, in this embodiment, the processor 51 included in the control unit 5 executes a control program 521 stored in the memory 52. This control program 521 can also be recorded on a computer-readable recording medium. The recording medium can be a magnetic or optical recording medium or a semiconductor memory device. Specifically, examples include portable or fixed recording media such as flexible disks, HDDs, CD-ROMs (Compact Disk Read Only Memory), DVDs, Blu-ray (registered trademark) discs, magneto-optical disks, flash memories, and card-type recording media. The recording medium may be a non-volatile storage device such as a RAM, a ROM, or a HDD, which is an internal storage device provided in the control unit 5. The control program 521 may be stored in a server device or the like, and the control program 521 may be downloaded from the server device to the control unit 5. [Explanation of symbols]

[0057] 100 Particle size distribution measuring device 1 Measuring mechanism 15 flow cells 17 Detector 171 Photodetector 171A Specific light receiving element 2. Sample supply mechanism 3 A / D converter 5. Control section 51 processors 511 Acquisition Department 512 Generation part 513 Judgment section 514 Measurement Execution Unit 52 memory 521 Control Program 522 Standard deviation memory section 61 Operating mechanism 62 Display mechanism DL light intensity distribution DP particle size distribution PR indicators SP sample TH threshold θ angle of incidence θ1 1st angle

Claims

1. A particle size distribution measuring apparatus that measures the particle size distribution of a particle group in a sample based on a light intensity distribution obtained by irradiating a sample with light from a light source and receiving light diffracted and scattered by the sample with a plurality of light receiving elements, comprising: a generation unit that generates an index for determining a diffusion state of a particle group in the sample based on the light intensity distribution in a first period and the light intensity distribution in a second period that is later than the first period; a determination unit that determines whether or not the diffusion state of the particle group in the sample has stabilized based on the index, Particle size distribution measuring device.

2. a measurement execution unit that starts measuring the particle size distribution based on the light intensity distribution when the determination unit determines that the diffusion state of the particle group in the sample has stabilized. The particle size distribution measuring device according to claim 1 .

3. The generation unit generating, as the index, a difference between a first standard deviation, which is a standard deviation of the light intensity during the first period, detected by a specific light receiving element that is at least one predetermined light receiving element among the plurality of light receiving elements, and a second standard deviation, which is a standard deviation of the light intensity during the second period, detected by the specific light receiving element; The particle size distribution measuring device according to claim 1 or 2.

4. The generation unit generating, as the index, a difference between a first difference, which is a difference between a maximum value and a minimum value of the light intensity detected by a specific light receiving element, which is at least one predetermined light receiving element among the plurality of light receiving elements, during the first period, and a second difference, which is a difference between a maximum value and a minimum value of the light intensity detected by the specific light receiving element during the second period; The particle size distribution measuring device according to claim 1 or 2.

5. The specific light receiving element is a light receiving element among the plurality of light receiving elements, the light receiving element having an incident angle equal to or smaller than a predetermined first angle. The particle size distribution measuring device according to claim 3 .

6. the determining unit determines that the diffusion state of the particle group in the sample is stable when the difference between the first standard deviation and the second standard deviation is equal to or less than a preset threshold value. The particle size distribution measuring device according to claim 3 .

7. A particle size distribution measuring device that measures the particle size distribution of a particle group in a sample based on a light intensity distribution obtained by irradiating a sample with light from a light source and receiving light diffracted and scattered by the sample with a plurality of light receiving elements, comprising: a generation step of generating an index for determining a diffusion state of a particle group in the sample based on the light intensity distribution in a first period and the light intensity distribution in a second period after the first period; and determining whether or not the diffusion state of the particle group in the sample has stabilized based on the index. A method for determining the diffusion state of particles in a sample.

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