JP2011007605A - Particle size measurement apparatus and particle size measurement method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a particle size measurement apparatus and a particle size measurement method for calculating a particle size of a particle group which can not be electrophoresed even if a voltage is applied.SOLUTION: The particle size measurement apparatus 10 is provided with: a measurement cell 1 in which a medium passes in the first configuration direction; an introduction port group 16 having a plurality of introduction ports 16a formed in the second configuration direction at a configuration interval, and introducing a sample containing the to-be-measured particle group in the medium from a plurality of the introduction ports 16a into the measurement cell 1; a light source 4a for irradiating the to-be-measured particle group within the measurement cell 1 with a measurement light in the third configuration direction; and a detector 50 for detecting a diffraction light intensity due to a diffraction light generated by irradiating the to-be-measured particle group within the measurement cell 1 with the measurement light. The appratus 10 diffuses the to-be-measured particle group in the second configuration direction within the medium while the to-be-measured particle group passes in the first configuration direction within the measurement cell 1, and is also provided with a particle size calculating section 35 for calculating the particle size of the to-be-measured particle group based on a change in the diffraction light intensity in the first configuration direction.

Description

  The present invention relates to a particle size measuring apparatus and a particle size measuring method for calculating the particle size of a group of particles to be measured using an optical method (for example, an induction diffraction grating method (IG method), etc.), and particularly formed in a medium. Using a transient diffraction grating (hereinafter also referred to as “density diffraction grating”) based on the particle density distribution of the particle group to be measured, the diffusion coefficient of the particle group to be measured is calculated, and further the particle diameter is calculated from the diffusion coefficient. The present invention relates to a particle diameter measuring apparatus and a particle diameter measuring method.

  Measurement of particle size d of particles dispersed in a medium (eg, liquid such as water, gel, etc.) is a product whose particle size d such as pharmaceutical, chemical, abrasive, ceramics and pigments affects quality. Has been done about. Furthermore, particles having a particle diameter d of 100 nm or less are generally referred to as nanoparticles, and even if they are the same material, they exhibit properties different from ordinary bulk materials, and thus are beginning to be used in various fields.

As a measurement method for measuring the particle diameter d of the nanoparticles, the electric field distribution having a spatial periodic pattern is generated in a sample in which the particles are dispersed in a medium, thereby causing the particles to undergo dielectrophoretic action (or electrophoretic action). By moving with the above, a density diffraction grating in which a dense region and a sparse region of particle groups are periodically arranged in a medium is formed, and laser light (measurement light) is irradiated to the density diffraction grating, after detecting the diffracted light intensity I _t0 by density grating, by stopping to generate an electric field distribution, the time of the diffracted light intensity I _t by density diffraction grating go blurred by diffusing particles in a medium A method is disclosed in which the diffusion coefficient D of the particle group is calculated by measuring the change, and further the particle diameter d is calculated from the diffusion coefficient D (see, for example, Patent Document 1).

According to such a measuring method, since the diffusion coefficient D increases as the particle diameter d decreases, the fact that the formed density diffraction grating disappears earlier is utilized. Specifically, until when the density grating disappears that to generate an electric field distribution from the diffusion start time t ₀ of stopping, by continuing to detect the diffracted light intensity I _t by irradiating a laser beam to the sample , it measures the time change of the diffracted light intensity I _t.
FIG. 10A is a graph showing the relationship between the voltage value V for generating the electric field distribution and the time t, and FIG. 10B is a graph showing the relationship between the diffracted light intensity I and the time t. In FIG. 10a, it applies a voltage between the frequency _{f n} and the voltage value _{V n} and the applied time Delta] t _n. Then, the start time of the application time Delta] t _n is the dielectrophoretic effect start time t _s, end time becomes ₀ diffusion start time t of the application time Delta] t _n, detected spreading start time t ₀ diffracted light intensity I _t Becomes the diffracted light intensity _It0 .

Then, in order to calculate the diffusion coefficient D from the time change of the diffracted light intensity I _t, and using the following equation (1).
I _t = I _t0 exp (−2Dq ² t) (1)
Here, q = 2π / Λ, t is time elapsed from the diffusion starting time t _0, I _t0 the diffracted light intensity detected in the diffusion starting time t _0, I _t is the diffracted light intensity detected in the time t, Λ is the grating spacing of the density diffraction grating.
Next, after calculating the diffusion coefficient D, the particle diameter d is calculated from the diffusion coefficient D by inputting the absolute temperature T and the viscosity μ of the medium using the Einstein-Stokes relationship represented by the following formula (2). ing.
_{D = K B T / 3πμd ·····} (2)
Here, _{K B} is the Boltzmann constant.

FIG. 6 is a schematic block diagram showing the overall configuration of a particle size measuring apparatus using such a measuring method. FIG. 7 is a perspective view showing an example of a sample cuvette (cell).
The particle diameter measuring apparatus 210 includes a sample cuvette 201 in which a sample is accommodated, an AC power source 203 that applies an AC voltage to an electrode pair 202 provided in the sample cuvette 201, and a laser beam ( comprises a laser light source 204 for irradiating the measurement light), a detection optical system 150 for detecting the first-order diffracted light intensity I _t, an amplifier 6, and a control unit 207 for controlling the overall particle size measurement device 210 .

The sample cuvette 201 is made of glass having a rectangular bottom surface 212 and four side walls 211, and has optical transparency. A sample is accommodated in the sample cuvette 201.
An electrode pair 202 is formed on the surface (inner surface) of one side wall 211 of the sample cuvette 201. FIG. 8 is a plan view showing an example of the side wall 211 on which the electrode pair 202 is formed, and FIG. 9 is a cross-sectional view showing a part of the cross section of the sample cuvette 201.
The electrode pair 202 includes a left electrode 221 and a right electrode 222.
The left electrode 221 includes linear electrode pieces 221a having a width L (for example, 1 μm) arranged in parallel with a space therebetween, and linearly connecting the outer ends of these electrode pieces 221a electrically. A connection portion 221b is provided to form a so-called comb electrode.
The right electrode 222 is the same as the left electrode 221, and linear electrode pieces 222 having a width L (for example, 1 μm) are arranged in parallel with a space therebetween, and one side ends on the outer sides of these electrode pieces 222a are arranged. A linear connection portion 222b that is electrically connected is provided to form a so-called comb-shaped electrode.
And each space | interval of the electrode piece 221a and the electrode piece 222a is arrange | positioned at predetermined distance S (for example, 10 micrometers), respectively.
Further, the AC power source 203 is connected to the upper end portion of the connection portion 221b and the upper end portion of the connection portion 222b.

Accordingly, an electric field distribution is formed in the sample cuvette 201 by applying an AC voltage from the AC power source 203 to the electrode pair 202. Then, a particle group aggregates by the dielectrophoresis between the electrode piece 221a and the electrode piece 222a where electric lines of force concentrate. On the other hand, no particle group exists due to dielectrophoresis between the electrode pieces 221a and 221a and between the electrode pieces 222a and 222a. Accordingly, the region P in which the particle group is aggregated is formed so as to have the lattice interval Λ (see FIG. 9a). That is, the region P in which the particle group is aggregated has a higher particle density than the other regions and has a different refractive index, so that a density diffraction grating having a lattice interval Λ is formed.
In addition, if an AC voltage from the AC power source 203 is not applied to the electrode pair 202, an electric field distribution is not formed in the sample cuvette 201. Therefore, there is no region where electric lines of force are concentrated, and particles are present uniformly in the medium. (See FIG. 9b). That is, the particle density is uniform and the refractive index is the same.

  Examples of the material of the electrode pair 202 include ITO, and the refractive index of ITO is about 2.0. As a material of the side wall 211 of the sample cuvette 201, high refractive index glass (for example, a trade name “s -LAH79 "; manufactured by OHARA; refractive index 2.0) eliminates the refractive index difference between the electrode pair 202 and the side wall 211, thereby generating diffracted light by the electrode pair 202 during laser light irradiation. Can be suppressed.

The AC power source 203 is an AC power source that can apply an AC voltage having a frequency f _n , a voltage value V _n, and an application time Δt _n that can cause dielectrophoresis in the particle group. Specifically, an AC power source or the like that can be freely selected from a voltage value of 1 to 100 V and a frequency of about 10 kHz to 10 MHz and can apply the selected AC voltage is used.
The type of the laser light source 204 may be selected according to the particle group, and is, for example, a He—Ne laser light source (wavelength λ = 0.6328 μm). The sample cuvette 201 is irradiated with laser light.

Detecting optical system 150 includes a detector 151 for detecting the first-order diffracted light intensity _{I t,} circular diameter 1mm to avoid unnecessary noise light (area: 0.785 mm ²⁾ pins having a pin hole It comprises a hall plate 152 and an optical axis adjusting light receiving portion 153 for grasping the position of the optical axis L of the laser light source 204.
The detector 151 is composed of one photodiode (light receiving element). In front of the detector 151, a pinhole is arranged so as to detect only the diffracted light of the order m diffracted by the density diffraction grating by the particle group out of the laser light emitted from the laser light source 204.
Here, when the lattice spacing Λ of the density diffraction grating, the wavelength λ of the laser beam, the diffraction angle θ, and the order m, the following formula (3) is established.
mλ = Λ · sinθ (3)
Therefore, for example, when λ = 0.6328 μm and Λ = 18 μm, m = 1st-order diffracted light appears at θ≈2 °, so that light having an angle θ≈2 ° with respect to the optical axis L is pinned. A pinhole plate 152 is disposed so as to pass through the hole.

JP 2006-84207 A

  By the way, in order to electrically migrate particles, electrostatic electrophoresis is used by applying voltage to charged particles, and dielectrophoresis is applied to polarized particles. Is used. However, even when a voltage value of 1 to 100 V and a frequency of about 10 kHz to 10 MHz are selected and a selected voltage is applied, there may be a sample in which it is difficult to migrate the particle group.

In order to solve the above problems, the present inventor has studied a method capable of calculating the particle diameter of a particle group that cannot be migrated even when a voltage is applied.
Thus, by applying a voltage to migrate the particle group, a density diffraction grating is not formed, but a circle having a diameter of 5 μm formed so as to be arranged at 20 μm (set interval) in the X direction (second set direction). It has been found that a density diffraction grating is formed by introducing a sample into a medium at a measurement site from a shape introduction port. Furthermore, by stopping the generation of the electric field distribution, as the time t passes, the density diffraction grating is not blurred by diffusing the particle group in the medium. It has been found that by passing in the direction (first setting direction), the density diffraction grating becomes blurred by diffusing the particle group in the medium as it goes downstream (Y direction) from the introduction port.

  That is, the particle size measuring device of the present invention is formed such that the measurement cell through which the medium passes in the first setting direction and the plurality of inlets are set at a set interval in the second setting direction perpendicular to the first setting direction. The first setting is made for the inlet group for introducing the sample containing the group of particles to be measured in the medium into the measurement cell from the plurality of inlets, and the group of particles to be measured in the measurement cell. A light source that irradiates measurement light in a third setting direction that is perpendicular to the direction and the second setting direction, and diffracted light intensity by diffracted light generated by irradiating the measurement light to the group of particles in the measurement cell A particle size measuring device for diffusing the measured particle group in the second setting direction in the medium while passing the measured particle group in the first setting direction in the measurement cell. Based on the change in the diffracted light intensity in the first setting direction. The so that comprise a part out particles diameter calculation for calculating the particle diameter of the particles to be measured.

Here, as the “measurement light”, laser light is preferable, but not limited to this, light by an LED, light dispersed by a spectroscope, light having a wavelength range limited by an interference filter, a bandpass filter, or the like is used. May be.
Further, the “medium” is not limited as long as the group of particles to be measured can migrate inside, and examples thereof include liquids such as water and oil.
In addition, the “diffracted light intensity” does not have to be the numerical value itself detected by the detector, and there may be the light intensity of the initial excess light that is detected even after the density diffraction grating disappears. The difference between the numerical value detected by the detector and the numerical value of the initial surplus light is preferable.
Further, the “set interval” may be an interval at which diffracted light can be generated by the particle group to be measured by irradiating measurement light, and is arbitrarily set within a range of 5 μm to 50 μm, for example.

In the particle size measuring apparatus of the present invention, the medium passes through the measurement cell in the first setting direction (Y direction). And the several inlet for introducing a sample in a measurement cell is formed so that it may become a setting space | interval in a 2nd setting direction (X direction). Thereby, the particle group to be measured just introduced into the measurement cell corresponds to a dense region corresponding to a position where a plurality of inlets are formed and a position where a plurality of inlets are not formed. Spatial periodic concentration changes occur at a set interval, that is, a density diffraction grating is formed by a group of particles to be measured. By irradiating the measurement light from the light source toward the particle group to be measured near the position y ₀ where the plurality of introduction ports are formed, diffracted light by the density diffraction grating is generated. At this time, since the density diffraction grating is stably formed, the diffracted light intensity I _y0 is increased.

The measured particle group diffuses in the second setting direction (X direction) in the medium while passing through the measurement cell in the first setting direction (Y direction), that is, the density diffraction grating is broken and blurred. Will go. That is, if the position where the measurement light is irradiated from the light source toward the particle group to be measured is shifted in the first setting direction (Y direction), the density diffraction grating will be broken and blurred. I _y is getting weaker. Therefore, a change in the diffracted light intensity I _y in the first setting direction (Y direction) is acquired.
Finally, on the basis of the change in the diffracted light intensity I _y in the first setting direction (Y direction), by substituting the expression for the position y instead of the time t in the above expressions (1) and (2), The particle diameter d is calculated by calculating the diffusion coefficient D of the particles to be measured.

  As described above, according to the particle size measuring apparatus of the present invention, the particle size of a group of particles to be measured that cannot be migrated even when a voltage is applied can be calculated.

(Means and effects for solving other problems)
In the particle size measurement apparatus of the present invention, the light source has a beam expander that spreads measurement light in a setting range in the first setting direction, and a plurality of detectors are provided in the setting range in the first setting direction. The light receiving elements may be arranged side by side.
Moreover, in the particle diameter measuring apparatus of this invention, you may make it have a drive part which moves the set of the said light source and a detector, or the said measurement cell to a 1st setting direction.
Furthermore, the particle size measuring apparatus of the present invention includes a pump for introducing a medium into the measurement cell, and a pump control unit for controlling the pump, and the pump control unit first sets the inside of the measurement cell. The flow rate of the medium flowing in the direction may be adjusted.
According to the particle size measuring apparatus of the present invention, the change in which the measured particle group diffuses in the second setting direction in the medium while the measured particle group passes in the first setting direction in the measurement cell can be accurately performed. As a result, the particle diameter of the particle group to be measured can be accurately calculated.

  Further, the particle size measuring method of the present invention is formed so that the measurement cell through which the medium passes in the first setting direction and the plurality of inlets are set at a set interval in the second setting direction perpendicular to the first setting direction. The first setting is made for the inlet group for introducing the sample containing the group of particles to be measured in the medium into the measurement cell from the plurality of inlets, and the group of particles to be measured in the measurement cell. A light source that irradiates measurement light in a third setting direction that is perpendicular to the direction and the second setting direction, and diffracted light intensity by diffracted light generated by irradiating the measurement light to the group of particles in the measurement cell A particle diameter measuring device that diffuses the measured particle group in the second setting direction in the medium while passing the measured particle group in the first setting direction in the measurement cell. A method for measuring a particle size, wherein the diffracted light in the first setting direction Based on a change in time, the it is to include the particle diameter calculation step of calculating the particle diameter of the particles to be measured.

1 is a schematic configuration block diagram showing an overall configuration of a particle size measuring apparatus according to an embodiment of the present invention. It is sectional drawing which shows an example of a measurement cell. It is sectional drawing of the A-A 'line shown to FIG. 2a. It is sectional drawing of the B-B 'line shown to FIG. 2a. It is a schematic block diagram which shows the whole structure of the particle diameter measuring apparatus which is other one Embodiment of this invention. It is sectional drawing which shows an example of a measurement cell. It is sectional drawing of the C-C 'line shown to FIG. 4a. It is sectional drawing of the D-D 'line | wire shown to FIG. 4a. It is a graph which shows the relationship between a diffracted light intensity and a position. It is a schematic block diagram which shows the whole structure of the conventional particle diameter measuring apparatus. It is a perspective view which shows an example of the conventional sample cuvette. It is a top view which shows an example of the side wall in which the electrode pair was formed. It is sectional drawing which shows a part of cross section of a sample cuvette. It is the graph which shows the relationship between a voltage value and time, and the graph which shows the relationship between diffracted light intensity and time.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments described below, and it goes without saying that various aspects are included without departing from the spirit of the present invention.

<Embodiment 1>
FIG. 1 is a schematic block diagram showing the overall configuration of a particle size measuring apparatus according to an embodiment of the present invention.
In this embodiment, XYZ coordinates are set, and the diffusion coefficient D of the particle group to be measured is calculated by dispersing the particle group to be measured in the Y direction while passing through the medium in the Y direction. Furthermore, the particle diameter d of the particle group to be measured is calculated from the diffusion coefficient D. A medium having a known viscosity μ is used.
The particle diameter measuring apparatus 10 includes a measurement cell 1, a sample injection part 11 into which a group of particles to be measured is injected, a liquid tank 12 for storing a medium, and a first medium for guiding the medium in the liquid tank 12 to the measurement cell 1. The pump 13, the second pump 14 that guides the medium in the liquid tank 12 to the sample injection unit 11, the waste liquid tank 15 that stores the sample from the measurement cell 1, and the sample from the sample injection unit 11 inside the measurement cell 1 A laser light source device 4 for irradiating laser light (measurement light), a detection optical system 5 for detecting the diffracted light intensity I _y , an amplifier 6, and the entire particle diameter measuring device 10. And a control unit 7 for controlling.

Here, FIG. 2a is a cross-sectional view showing an example of a measurement cell, FIG. 2b is a cross-sectional view taken along the line AA 'shown in FIG. 2a, and FIG. 2c is a cross-sectional view taken along the line BB' shown in FIG. FIG. In FIG. 2c, the laser light source device 4 and the detection optical system 5 are also shown.
The measurement cell 1 has a rectangular tube shape having a cavity in the Y direction (first setting direction), and is made of glass having a bottom surface 1a, a top surface 1b, and two side walls 1c, and a Z direction (third). Light transmission in setting direction). And while one end part (− side in the Y direction) of the measurement cell 1 is connected via the liquid tank 12 and the first pump 13, the other end part (+ side in the Y direction) of the measurement cell 1 is It is connected to the waste liquid tank 15. Accordingly, when the first pump 13 is operated by the control unit 7, the medium passes through the measurement cell 1 from the − side in the Y direction to the + side.
The sample injection unit 11 is configured to inject a group of particles to be measured. One end of the sample injection section 11 is connected to the medium tank 12 via the second pump 14, and the other end of the sample injection section 11 is connected to the inlet group 16. Thus, when the second pump 14 is operated by the control unit 7, a sample in which the measured particle group is contained in the medium is prepared in the sample injection unit 11, and the sample is guided to the inlet group 16. It has become.

The introduction port group 16 is formed in the vicinity of one end portion (− side in the Y direction) of the bottom surface 1a. The inlet group 16 includes a plurality of circular inlets 16a having a diameter of 5 μm (= L). The plurality of introduction ports 16a are arranged so as to be arranged at 20 μm (setting interval S) in the X direction (second setting direction). At this time, the introduction ports 16a at both ends are preferably formed so as to be sufficiently spaced from the side wall 1c, and the diameter of the introduction port 16a is preferably 1 μm or more and 10 μm or less.
Thus, by introducing a sample containing the group of particles to be measured in the medium from the plurality of inlets 16a into the measurement cell 1, the group of particles to be measured passes through the measurement cell 1 in the Y direction. . At this time, the particle group to be measured is a dense region in the vicinity of the introduction port group 16 so as to correspond to the position where the plurality of introduction ports 16a are formed, and corresponds to the position where the plurality of introduction ports 16a are not formed. Thus, the area becomes sparse (see FIGS. 2a and 2c). That is, a spatial periodic concentration change occurs in which dense and sparse regions are arranged at 20 μm in the X direction, that is, a density diffraction grating is formed by a group of particles to be measured.
Then, the particle group to be measured diffuses in the X direction in the medium while passing through the measurement cell 1 in the Y direction, that is, the density diffraction grating gradually collapses and becomes blurred.

The laser light source device 4 includes a laser light source 4a that irradiates laser light, and a beam expander 4b that spreads measurement light in a setting range y0 to y6 (= Δy) in the Y direction. The type of the laser light source 4a may be selected according to the group of particles to be measured. For example, it is a He—Ne laser light source (wavelength λ = 0.6328 μm). The group of particles to be measured in the measurement cell 1 is irradiated with laser light in the Z direction (third setting direction). At this time, the laser beam is irradiated in the Z direction to the measured particle group in the setting range y0 to y6 in the measurement cell 1 by the beam expander 4b.
The detection optical system 5 includes a detector 50 in which a plurality of (for example, seven) photodiodes (light receiving elements) 50a are arranged in order in a set range y0 to y6 in the Y direction, and a laser light source 4a. And a cylindrical lens 51 for detecting only the diffracted light of order m = 1 diffracted by the density diffraction grating by the group of particles to be measured (see FIG. 2c). Accordingly, the first (y0) photodiode 50a detects the first-order diffracted light intensity _Iy0 , and the second (y1) photodiode 50a detects the first-order diffracted light intensity _Iy1 . Thus, a change in the first-order diffracted light intensity I _y in the Y direction is detected.

The control unit 7 includes a CPU 30 and a memory 40, and is connected to a display device (not shown) having a monitor screen and an input device (not shown) having a keyboard, a mouse, and the like. Further, the functions processed by the CPU 30 will be described as a block. The pump control unit 31 that controls the first pump 13 and the second pump 14, the laser light source control unit 32 that controls the laser light source device 4, and the light intensity. It consists of a light intensity acquisition control unit 36 that captures I _y and a particle size calculation unit 35 that calculates the particle size d.

The laser light source control unit 32 controls the laser light source 4a so as to irradiate the laser beam in the Z direction (ON) or stop the irradiation (OFF).
The light intensity acquisition control unit 36 performs control to acquire the light intensity I _x by the plurality of photodiodes 50a and detect a change in the first-order diffracted light intensity I _{x in} the Y direction.

The pump control unit 31 controls the first pump 13 and the second pump 14.
For example, since the diffusion coefficient D increases as the particle diameter d decreases, the flow rate is increased using the first pump 13 and the second pump 14 when the density diffraction grating quickly collapses and becomes blurred during measurement. Thus, the speed s of the sample passing through the measurement cell 1 is increased to shorten the time for passing through the set range y0 to y6 in the measurement cell 1, and as a result, the density diffraction grating is made to be the length of the measurement cell 1 in the Y direction. In contrast, it gradually collapses and blurs.
On the other hand, since the diffusion coefficient D decreases as the particle diameter d increases, the flow rate is decreased using the first pump 13 and the second pump 14 when the density diffraction grating gradually collapses and becomes blurred during measurement. As a result, the speed s of the sample passing through the measurement cell 1 is slowed down and the time for passing through the set range y0 to y6 in the measurement cell 1 is lengthened. As a result, the density diffraction grating is lengthened in the Y direction of the measurement cell 1. It will quickly break down and blur.

Based on the change in the first-order diffracted light intensity I _y in the Y direction obtained by the light intensity acquisition controller 36, the particle diameter calculator 35 calculates the time t in the above equations (1) and (2). Instead, by substituting an expression relating to the position y, the diffusion coefficient D of the particle group to be measured is calculated, and control for calculating the distribution of the particle diameter d is performed (particle diameter calculating step). The time t to be substituted into the above equations (1) and (2) from the flow velocity s and the position y of the liquid medium flowing in the Y direction in the measurement cell 1 is calculated from t = y / s.
Here, FIG. 5 is a graph showing the relationship between the diffracted light intensity and the position. With taking a diffracted light intensity I _t on the vertical axis, taking a position y on the horizontal axis. The further in the Y direction, the weaker the diffracted light intensity I _y becomes.
According to such a change in the first-order diffracted light intensity I _{y in} the Y direction, the diffusion start time t _{0 at} time t shown in FIG. 10b and the diffusion start position y _{0 at} position y shown in FIG. Accordingly, the diffracted light intensity _It0 shown in FIG. 10b corresponds to the diffracted light intensity _Iy0 shown in FIG. Then, the time t that has elapsed since the diffusion starting time t ₀ at time t shown in FIG. 10b, since the position y / velocity s will correspond, the diffracted light intensity I _t shown in FIG. 10b, the diffracted light intensity I _{y / s} corresponds.
As described above, according to the particle size measuring apparatus 10 of the first embodiment, the particle size of the measured particle group that cannot be migrated even when a voltage is applied can be calculated.

<Embodiment 2>
FIG. 3 is a schematic block diagram showing the overall configuration of a particle size measuring apparatus according to another embodiment of the present invention.
In the present embodiment, unlike the above-described first embodiment, the measurement cell 101 is moved in the Y direction.

The particle diameter measuring apparatus 110 includes a measurement cell 101, a sample injection unit 11 into which a group of particles to be measured is injected, a liquid tank 12 that stores a medium, and a first medium that guides the medium in the liquid tank 12 to the measurement cell 101. The pump 13, the second pump 14 that guides the medium in the liquid tank 12 to the sample injection unit 11, the waste liquid tank 15 that stores the sample from the measurement cell 101, and the sample from the sample injection unit 11 inside the measurement cell 101 , A laser light source device 104 that emits laser light (measurement light), a detection optical system 105 for detecting the diffracted light intensity I _y , an amplifier 6, and a cell that moves the measurement cell 101. The drive part 54 and the control part 107 which controls the particle diameter measuring apparatus 110 whole are provided.

4a is a cross-sectional view showing an example of the measurement cell, FIG. 4b is a cross-sectional view taken along the line CC ′ shown in FIG. 4a, and FIG. 4c is a line DD ′ shown in FIG. 4a. FIG. FIG. 4 c also shows the laser light source device 104 and the detection optical system 105.
The measurement cell 101 has a rectangular tube shape having a cavity in the Y direction (first setting direction), is made of glass having a bottom surface 101a, a top surface 101b, and two side walls 101c, and is formed in the Z direction (third). Light transmission in setting direction). And while one end part (− side in the Y direction) of the measurement cell 101 is connected via the liquid tank 12 and the first pump 13, the other end part (+ side in the Y direction) of the measurement cell 101 is It is connected to the waste liquid tank 15. Accordingly, when the first pump 13 is operated by the control unit 107, the medium passes through the measurement cell 101 from the negative side to the positive side in the Y direction.
The sample injection unit 11 is configured to inject a group of particles to be measured. One end of the sample injection section 11 is connected to the medium tank 12 via the second pump 14, and the other end of the sample injection section 11 is connected to the inlet group 116. As a result, when the second pump 14 is operated by the control unit 107, a sample in which the measured particle group is contained in the medium is prepared in the sample injection unit 11, and the sample is guided to the inlet group 116. It has become.

The introduction port group 116 is formed at one end (−side in the Y direction) of the measurement cell 101. The inlet group 116 includes a plurality of circular inlets 116a having a diameter of 5 μm (= L). The plurality of inlets 116a are arranged so as to be arranged at 20 μm (set interval S) in the X direction (second set direction). In comparison with the first embodiment, the inlet group 116 is formed on the side portion of the measurement cell 101, unlike the inlet group 16 formed on the bottom surface 1 a of the measurement cell 1. Therefore, the medium is introduced into the measurement cell 101 from between the plurality of introduction ports 116a. Further, the introduction port 116a is circular when viewed from the Y direction, unlike the introduction port 16a that is circular when viewed from the Z direction.
Thus, by introducing a sample containing the particles to be measured in the medium into the measurement cell 101 from the plurality of inlets 116a, the particles to be measured pass through the measurement cell 101 in the Y direction. . At this time, the particle group to be measured is a dense region in the vicinity of the inlet group 116a so as to correspond to a position where the plurality of inlets 116a are formed, and corresponds to a position where the plurality of inlets 116a are not formed. Thus, the area becomes sparse (see FIGS. 4a and 4c). That is, a spatial periodic concentration change occurs in which dense and sparse regions are arranged at 20 μm in the X direction, that is, a density diffraction grating is formed by a group of particles to be measured.
Then, the measured particle group diffuses in the X direction in the medium while passing through the measurement cell 101 in the Y direction, that is, the density diffraction grating gradually collapses and becomes blurred.

The laser light source device 104 includes a laser light source 4a that emits laser light. The type of the laser light source 4a may be selected according to the group of particles to be measured. For example, it is a He—Ne laser light source (wavelength λ = 0.6328 μm). The group of particles to be measured in the measurement cell 1 is irradiated with laser light in the Z direction (third setting direction).
The detection optical system 105 includes only one diffracted light of order m = 1 diffracted by the density diffraction grating of the measured particle group out of the laser light emitted from one photodiode (light receiving element) 52 and the laser light source 4a. And a convex lens 53 for detection (see FIG. 4c). Accordingly, the first-order diffracted light intensity I _y is detected by the photodiode 52.

The cell driving unit 54 moves the measurement cell 101 in the Y direction. By the way, in Embodiment 2, laser light is irradiated in the Z direction onto a group of particles to be measured in a narrow range in the measurement cell 1. Therefore, since the change in the first-order diffracted light intensity I _{y in} the Y direction cannot be detected, the measurement cell 101 is moved in the Y direction. Thereby, when the measurement cell 101 is arranged at the initial position (y0), the first-order diffracted light intensity I _y0 is detected by the photodiode 52, and when the measurement cell 101 is arranged at the first position (y1), by the photodiode 52, so as to detect the first-order diffracted light intensity I _y1, detecting a first-order variation of the diffracted light intensity I _y in the Y direction.

The control unit 107 includes a CPU 30 and a memory 40, and is connected to a display device (not shown) having a monitor screen and an input device (not shown) having a keyboard, a mouse, and the like. Further, the functions processed by the CPU 30 will be described as a block. The pump control unit 31 that controls the first pump 13 and the second pump 14, the laser light source control unit 32 that controls the laser light source device 4, and the light intensity. The light intensity acquisition control unit 36 that captures I _y , the particle size calculation unit 35 that calculates the particle size d, and the drive unit control unit 34 that controls the cell drive unit 54.

The drive unit control unit 34 controls the cell drive unit 54 that moves the measurement cell 101 in the Y direction.
For example, first, the measurement cell 101 is arranged at the initial position (y0) for a predetermined time, and then the measurement cell 101 is repeatedly moved so as to be arranged at the first position (y1). Arrange from (y0) to the sixth position (y6). Thereby, a change in the first-order diffracted light intensity I _{y in} the Y direction is detected.
As described above, according to the particle size measuring apparatus 110 of the second embodiment, the particle size of the particle group to be measured that cannot be migrated even when a voltage is applied can be calculated.

(Other embodiments)
In the particle diameter measuring device 10, 110 described above, the detector 151, a configuration has been shown to be assumed to detect the first-order diffracted light intensity I _t, the diffracted light intensity of the second Tsugiya higher order it may be configured to detects the I _t. In the second embodiment, the measurement cell 101 is moved. However, the set of the laser light source 4a, the lens 53, and the photodiode 52 may be moved with respect to the measurement cell 101. Furthermore, instead of the measurement cell 101 of the second embodiment, the measurement cell 1 of the first embodiment may be used. Similarly, instead of the measurement cell of the first embodiment, the measurement cell 101 of the second embodiment may be used.

  The present invention uses a density diffraction grating formed by a group of particles to be measured formed in a medium, calculates the diffusion coefficient of the group of particles to be measured, and further uses it for a particle size measuring device that calculates the particle diameter from the diffusion coefficient. can do.

DESCRIPTION OF SYMBOLS 1, 101: Measurement cell 4a: Laser light source 10, 110, 100: Particle diameter measuring device 16, 116: Inlet port group 16a, 116a: Inlet port 35: Particle diameter calculating part 50, 151: Detector

Claims (5)

A measuring cell through which the medium passes in a first setting direction;
A plurality of introduction ports are formed at a set interval in a second setting direction perpendicular to the first setting direction, and a sample containing a group of particles to be measured in the medium is measured from the plurality of introduction ports. A group of inlets to be introduced into the cell;
A light source for irradiating measurement light in a third setting direction perpendicular to the first setting direction and the second setting direction with respect to the group of particles to be measured in the measurement cell;
A detector for detecting the intensity of diffracted light due to diffracted light generated by irradiating measurement light to a group of particles to be measured in the measurement cell;
A particle size measuring device that diffuses the particles to be measured in the second setting direction in the medium while passing the particles to be measured in the first setting direction in the measurement cell,
A particle diameter measuring apparatus comprising: a particle diameter calculating unit that calculates a particle diameter of the measured particle group based on a change in diffracted light intensity in the first setting direction. The light source has a beam expander that spreads measurement light to a setting range in a first setting direction,
The particle size measuring apparatus according to claim 1, wherein the detector is arranged so that a plurality of light receiving elements are arranged in a setting range in a first setting direction.   The particle size measuring apparatus according to claim 1, further comprising a drive unit that moves the set of the light source and the detector or the measurement cell in a first setting direction. A pump for introducing a medium into the measurement cell;
A pump control unit for controlling the pump,
The particle size measuring apparatus according to any one of claims 1 to 3, wherein the pump control unit adjusts a flow rate of a medium flowing in the measurement cell in a first setting direction. The measurement cell through which the medium passes in the first setting direction and a plurality of inlets are formed so as to be set intervals in the second setting direction perpendicular to the first setting direction, from the plurality of inlets, An inlet port group for introducing a sample containing the group of particles to be measured into the medium into the measurement cell, and a first set direction and a second set direction perpendicular to the group of particles to be measured in the measurement cell. A light source that irradiates measurement light in three setting directions, and a detector that detects the intensity of diffracted light generated by diffracted light generated by irradiating the measurement particle group in the measurement cell with the measurement light. A particle size measuring method using a particle size measuring apparatus that diffuses a group of particles to be measured in a second setting direction in the medium while passing the group in a first setting direction in a measurement cell,
A particle diameter measuring method comprising a particle diameter calculating step of calculating a particle diameter of the measured particle group based on a change in diffracted light intensity in the first setting direction.