JP2003329570A - Apparatus for measuring distribution of particle size - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus for measuring a distribution of particle size, which can surely detect scattering light with a scattering angle of about 90 degrees, surely detect scattering light through a wide angular range from zero to about 180 degrees and reproducibly measure the distribution of particle size over a wide range of particles. <P>SOLUTION: The apparatus for measuring the distribution of particle size has a light source 1, a sample cell 6 on which light from the light source 1 is projected, a condensing lens 3 which is disposed on optical axes 4a, 4b of the light, and a forward detector 5 which detects transmitting light and prescribed scattering light generated at the sample cell 6. In the apparatus, the sample cell 6 is set so as to incline in relation to the optical axis 4a of the light from the light source 1, and groups of wide angular scattering light detector 8, 9 composed of a plurality of detectors 10 are arranged on both sides of the sample cell 6. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention detects diffracted / scattered light generated by irradiating a dispersed particle group with laser light, and based on a scattered light intensity signal obtained by the detection, particles of the particle group are detected. The present invention relates to a particle size distribution measuring device for measuring a size distribution.

[0002]

2. Description of the Related Art In a particle size distribution measuring device utilizing the diffraction phenomenon and / or scattering phenomenon of light by a sample particle, the intensity distribution of diffracted light and / or scattered light, that is, the diffraction angle and / or the scattering angle and the light intensity The particle diameter distribution of the sample particles is calculated by measuring the relationship between the particle diameter distribution of the sample particles and the calculation processing based on the Fraunhofer diffraction theory and / or the Mie scattering theory.

FIG. 9 schematically shows a main part of an optical system in a conventional particle size distribution measuring apparatus. In this figure, reference numeral 81 indicates, for example, a liquid in which particles are dispersed in a dispersion medium (hereinafter referred to as a sample liquid). It is a sample cell that houses Reference numerals 82 and 83 denote a light source and a condenser lens provided on one side of the sample cell 81 in the thickness direction (irradiation light transmission direction), that is, on the rear side of the sample cell 81, and 84 denotes the thickness direction of the sample cell 81. The other side of the sample cell 81
Is a front detector composed of a photodiode array provided at the focal position of the condenser lens 83 on the front side of, and detects scattered light having a relatively small transmitted angle (for example, 0 ° to 30 °). The condenser lens 83 is formed in a so-called inverse Fourier optical system located on the light source 82 side. And
Reference numeral 85 denotes a wide-angle scattered light detector group for detecting scattered light (wide-angle scattered light) having a relatively large scattering angle (30 ° or more), and a plurality of photodiodes provided on one side of the sample cell 81 from front to back thereof. (Single channel detector) 86. Reference numeral 87 is a substrate that supports a plurality of single channel type detectors 86 in a predetermined state.

[0004]

In the above particle size distribution measuring apparatus, since the irradiation light (for example, laser light) 88 from the light source 82 is vertically incident on the sample cell 81, the scattering angle is When receiving the 90 ° side scattered light 89, it is necessary to provide the detector 86a in the lateral direction (direction orthogonal to the irradiation light transmitting direction) of the sample cell 81, but the sample cell 81 is wide as in the illustrated example. (Longer in the direction orthogonal to the incident direction of the light 88), the scattered light 89 is attenuated when passing through the sample cell 81, so that the signal output from the detector 86a is weakened. There is. Further, as indicated by reference numeral 90, scattered light with a scattering angle of about 90 ° may not be detected by any of the detectors 86 of the wide-angle scattered light detector group 85 due to total reflection on the surface of the sample cell 81. . That is, the conventional particle size distribution measuring device may not be able to reliably detect the side scattered light having a scattering angle of 90 ° or around 90 ° (hereinafter, simply referred to as 90 °). There is a problem that the measurement accuracy and data reproducibility of fine particles having a diameter of, for example, 1 μm or less are poor.

By the way, in the particle size distribution measuring apparatus constructed as shown in FIG. 9, the light transmitted through the sample cell 81 enters the transmitted light detecting portion of the front detector 84, is reflected there, and is reflected there. 81, the sample cell 81 is tilted at a very small angle with respect to the optical axis 88, for example, about 5 ° in order to prevent the reflected light from being reflected on the front surface of the sample cell 81 and heading again to the front detector 84. Have been attempted to be placed. However, even in such a case, as in the case shown in FIG. 9, the above-mentioned problems caused by the inability to reliably detect the side scattered light having a scattering angle of about 90 ° are encountered. there were.

Therefore, as a method for solving such a problem, instead of the rectangular parallelepiped sample cell 81, a lateral (see FIG.
It is conceivable that the portion indicated by the reference numeral 81a in FIG. 2) is curved so that the optical axis of the scattered light to be taken out and the boundary surface between the air in the sample cell 81 are as perpendicular as possible to prevent the total reflection. The sample cell having such a special shape is required to have high processing accuracy, which causes a problem of cost increase.

The above-mentioned problems are not limited to the so-called inverse Fourier optical system particle size distribution measuring apparatus, but a so-called concentrating lens is provided on the front side of the sample cell, and a so-called front detector is arranged at the focal position of this condensing lens. The same is occurring in the particle size distribution measuring device (not shown) of the Fourier optical system.

The present invention has been made in consideration of the above matters, and an object thereof is to be able to reliably detect scattered light with a scattering angle of about 90 °, and to obtain a scattered light of about 0 ° to 180 °. It is possible to reliably detect scattered light in a wide angle range,
An object of the present invention is to provide a particle size distribution measuring device capable of measuring the particle size distribution over a wide particle range with good reproducibility.

[0009]

To achieve the above object, the present invention provides a light source, a sample cell irradiated with light from the light source, and a condenser lens arranged on the optical axis of the light. in the particle size distribution measuring apparatus equipped with a front detector for detecting the transmitted light and a predetermined scattered light generated in the sample cell, the sample cell was tilted with respect to the optical axis of the light emitted from the light source state And a wide-angle scattered light detector group composed of a plurality of detectors is provided on both sides of the sample cell (claim 1).

In the particle size distribution measuring apparatus according to the first aspect, the condenser lens may be provided between the light source and the sample cell, and the front detector may be provided at the focal position of the condenser lens. (Claim 2) Alternatively, a condenser lens may be provided between the sample cell and the front detector, and the front detector may be provided at the focal position of the condenser lens (claim 4). And when comprised like said Claim 2, the transmitted light or the scattered light is converged on the light-receiving surface of the said front detector in any position on the optical axis between a condensing lens and a front detector. It is preferable to provide an optical compensator for the purpose (claim 3). When configured in this way, in the particle size distribution measuring device that employs the inverse Fourier optical system, the astigmatism caused by the oblique incidence of the irradiation light on the sample cell is eliminated, and the adverse effect on the measurement data is eliminated. be able to.

[0011]

DETAILED DESCRIPTION OF THE INVENTION The details of the invention will be described below with reference to the drawings. 1 and 2 show one embodiment of the first invention, FIG. 1 schematically shows an example of the configuration of a particle size distribution measuring apparatus of the present invention, and FIG. It shows a configuration. The optical system of the particle size distribution measuring device shown in FIG. 1 is an inverse Fourier optical system. That is, in FIGS. 1 and 2, 1 is a light source that emits laser light 2, for example, and 3 is this laser light source 1.
Is a condenser lens provided in front of the sample cell 6 described later.
The focused laser beam 4 is irradiated on the surface. Reference numeral 5 denotes a front detector provided at the focal position of the condenser lens 3, and the light receiving surface 5a thereof has a transmitted light detecting portion for detecting transmitted light and a transmitted light detecting portion such as a known ring detector. The scattered light detection unit has a plurality of arc-shaped photodiodes arranged in an array at the center, and the transmitted light generated in the sample cell 6 and the scattered angle are relatively small forward scattered light such as about 0 ° to 30 °. Is configured to detect.

Reference numeral 6 denotes a sample cell provided between the condenser lens 3 and the front detector 5 for containing a sample solution 7 in which a group of particles to be measured is dispersed in a dispersion medium, which is, for example, transparent. It is made of glass and has a rectangular parallelepiped shape.
The thickness t in the irradiation light transmission direction is considerably smaller than the length w in the width direction orthogonal to the irradiation light transmission direction. The sample cell 6 is arranged so as to be tilted backward by an angle θ with respect to the optical axis 4a of the condensed laser beam 4,
In the illustrated example, θ is 45 °. That is, the angle θ formed by the center line CL of the sample cell 6 and the optical axis 4a in the thickness direction.
Are arranged in an inclined state so that the angle is 45 °. When the condensed laser light 4 from the laser light source 1 side is incident on such a sample cell 6, its central optical axis 4a passes through the thickness portion of the sample cell 6 and the sample liquid 7 as shown in FIG. Optical axis 4b on the exit side of the sample cell 6
Is parallel to the optical axis 4a, although slightly displaced from it, and focuses on the transmitted light detecting portion of the front detector 5. In addition,
The sample cell 6 may be a flow-through type sample cell to which the sample liquid 7 is supplied in a flowable manner.

Reference numerals 8 and 9 denote wide-angle scattered light detector groups provided on both sides of the sample cell 6 (sides facing the entrance surface 6a and the exit surface 6b of the focused laser beam 4).
The wide-angle scattered light scattered / diffracted at a relatively large angle of, for example, 30 ° to 180 ° among the irradiation light diffracted or scattered by the particles inside is detected individually for each scattering angle. The light detection groups 8 and 9 are each composed of a plurality of photodiodes 10 arranged in a row at an angle different from that of the front detector 5, and depending on the respective arrangement angles,
It is possible to detect scattered light at a predetermined angle due to particles in the sample cell 1. In the illustrated example, one wide-angle scattered light detector group 8 is used.
Detects scattered light from 30 ° to 90 ° (forward scattered light and 90 ° side scattered light having a relatively large scattering angle), and the other wide-angle scattered light detector group 9 scatters from 90 ° to 180 °. The light (side scattered light and back scattered light) is detected.
Reference numeral 11 denotes an electric circuit board that holds the photodiode 10 so that the scattered light enters the light receiving surface of the photodiode 10 at a right angle and includes a preamplifier (not shown).

In FIG. 1, reference numeral 12 sequentially takes in the outputs from the front detector 5 and the electric circuit board 11,
A multiplexer that sequentially sends the signals to the AD converter 13, and a computer 14 as an arithmetic processing unit to which the output of the AD converter 13 is input. This computer 14 stores a program for processing the outputs of the front detector 5 and the photodiode 10 converted into digital signals based on the Fraunhofer diffraction theory and the Mie scattering theory to obtain the particle size distribution in the particle group. . Reference numeral 15 is a display device such as a color display for displaying a calculation result and the like.

In the particle size distribution measuring apparatus constructed as described above, when the laser light 2 is emitted from the laser light source 1 with the sample liquid 7 contained in the sample cell 6, the laser light 2 is condensed. The light is converged by the lens 3 and becomes the irradiation light 4, which irradiates the sample liquid 7 in the sample cell 6. The irradiation light 4 is diffracted or scattered by the particles in the sample cell 6. Of the diffracted light or scattered light, 0 ° to 30
Forward scattered light having a relatively small scattering angle such as ° is detected by the scattered light detecting section of the front detector 5. The irradiation light 4 which is not scattered by the particles becomes transmitted light,
It is detected by the transmitted light detecting portion of the front detector 5. The light intensity detected by the front detector 5 is converted into an analog electric signal, and further inputted to the multiplexer 12 via a preamplifier (not shown).

On the other hand, of the irradiation light 4 diffracted or scattered by the particles, the scattered light having a scattering angle exceeding 30 ° is
It is detected by the wide-angle scattered light detector groups 8 and 9. More specifically, the scattering angle of the scattered light is 30 ° to 90 °.
Part of the forward scattered light and the 90 ° side scattered light up to is detected for each scattering angle by the plurality of photodiodes 10 forming one wide-angle scattered light detector group 8, and the scattering angle is 90 ° to 180 °. Part of the back scattered light and the 90 ° side scattered light up to is detected by the plurality of photodiodes 10 constituting the other wide angle scattered light detector group 9 for each scattering angle. The light intensity detected by the photodiode 10 is converted into an analog electric signal, and further inputted to a multiplexer 12 via a preamplifier (not shown) provided on the electric circuit board 11.

In the multiplexer 12, the measurement data from the front detector 5 and the photodiodes 10, that is, the analog electric signals are sequentially fetched in a predetermined order. Then, the analog electric signal taken in by the multiplexer 12 is converted into a serial signal, sequentially converted into a digital signal by the AD converter 13, and further inputted to the computer 14.

In the computer 14, the light intensity data for each scattering angle obtained by the front detector 5 and each photodiode 10 are processed based on the Fraunhofer diffraction theory and the Mie scattering theory, and the processing result is , Is displayed in an appropriate form on the display screen of the display device 15.

In the particle size distribution measuring apparatus having the above-mentioned structure, the sample cell 6 is placed at 45 with respect to the optical axis 4a (or 4b).
Since it is tilted at 90 °, scattered / diffracted light around 90 ° can be reliably detected without being disturbed by total reflection or the like and by preventing attenuation thereof in the sample cell 6 as much as possible. can do. Furthermore, on both sides of the sample cell 6,
Since the wide-angle scattered light detector groups 8 and 9 in which a plurality of detectors 10 are provided in a row are arranged, not to mention the forward scattered light scattered / diffracted at a larger angle which is not detected by the front detector 5, It is possible to reliably detect 90 ° side scattered light and back scattered light without leakage. Further, scattered / diffracted light around 90 ° can be detected by the wide-angle scattered light detector groups 8 and 9, and the signal amount can be increased. Therefore, a sufficient amount of signal can be obtained for scattered / diffracted light around 90 °, and scattered light in a wide range from a scattering angle of around 0 ° to 180 ° can be continuously detected without leakage. Measurement accuracy and data reproducibility can be improved.

Further, according to the above configuration, the advantage of the inverse Fourier optical system that a long focal length can be secured as the condenser lens 3 can be enjoyed 100%, so that the scattering angle is, for example, 0 ° to 5 °. In order to detect such minute scattered light, an expensive front detector 5 that has been finely processed is not required, and a commercially available inexpensive diode array can be used. Further, since a long focal length can be ensured, scattered light with a small scattering angle can be detected even if the beam diameter of the focal point is increased. Therefore, the condenser lens 3 having a large focal beam diameter, that is, However, an inexpensive one can be used, and the device can be constructed inexpensively.

The present invention can be implemented with various modifications. This will be described below. In the first embodiment, the tilt angle θ of the sample cell 6 with respect to the optical axis 4a (or 4b) is 45 °, and the sample cell 6 is easily tilted with respect to the optical axis 4a (or 4b). However, the angle θ is not limited to this,
For example, it can be set to any angle from 25 ° to 65 °. This is disadvantageous in that if the angle θ is too small, total reflection in the sample cell 6 and multiple reflection of light inside the sample cell 6 cannot be reliably prevented, and if the angle θ is too large, in the sample cell 6 there is a problem. This is because the optical path length is increased, the signal to the front detector 5 is weakened, and the adverse effects of multiple reflection of light in the sample cell 6 cannot be prevented. The tilt angle θ can be set to any size without departing from the gist of the present invention.
It is not limited to the angle range.

Further, although the sample cell 6 is tilted rearward in the above embodiment, it may be tilted forward instead.

In the above-described embodiment, the optical system is a so-called inverse Fourier optical system, but as shown in FIG. 3, for example, the condenser lens 3 is connected to the sample cell 6 and the front detector 5. The optical system may be configured as a so-called Fourier optical system by providing the front detector 5 at the focal position of the condenser lens 3 as well as the optical system.

The wide-angle scattered light detector groups 8 and 9 provided on both sides of the sample cell 6 are not necessarily limited to the arrangement shown in FIG. 2, but as shown in FIG. You may arrange | position so that it may become parallel to the width direction (longitudinal direction). The optical system in FIG. 4 is an inverse Fourier system, but it goes without saying that it may be a Fourier optical system.

In each of the above embodiments, the plurality of photodiodes 10 in the wide-angle scattered light detector groups 8 and 9 are arranged on a flat substrate, and are arranged in a straight line. It is not limited to this,
For example, as shown in FIG. 5, the photodiodes 10 in each of the wide-angle scattered light detector groups 8 and 9 may be arranged in a curved shape by providing the photodiodes 10 on a curved substrate 11A. The optical system in FIG. 5 is an inverse Fourier system, but it goes without saying that it may be a Fourier optical system.

The distribution of scattered light received by the wide-angle scattered-light detector groups 8 and 9 provided on both sides of the sample cell 6 is not limited to the above-mentioned numerical range, but the wide-angle scattered-light detector groups 8 and The installation position of 9 is appropriately shifted to the front or the rear of the sample cell 6, or the optical axis 4a of the wide-angle scattered light detector groups 8 and 9 is used.
It can be appropriately set by widening or narrowing the installation range in the (or 4b) direction.

By the way, the optical system in the particle size distribution measuring apparatus is roughly classified into an inverse Fourier optical system (see FIGS. 1, 2, 4 and 5) and a Fourier optical system (see FIG. 3). From the viewpoint of space saving, the former is superior. However, in the inverse Fourier optical system, when the sample cell 92 is arranged so as to be inclined with respect to the optical axis 91, as shown in FIG. The length of the light beam varies depending on the light rays, and astigmatism may cause defocusing on the light receiving surface 94a of the front detector 94, which may adversely affect the measurement data. In addition, 95 is a light source and 96 is a condenser lens. Further, such inconvenience does not occur in the Fourier optical system.

Therefore, in the second invention, in the particle size distribution measuring apparatus employing the inverse Fourier optical system, at any position on the optical axis between the condenser lens and the front detector,
An optical compensator composed of a flat plate-like light transmitting member such as glass for converging scattered light on the light receiving surface of the front detector is provided in a state of being inclined in a direction opposite to the direction of inclination of the sample cell. . Hereinafter, the second invention will be described with reference to FIGS.

First, FIG. 6 shows one embodiment of the second invention, and schematically shows the structure of a main part of a particle size distribution measuring apparatus employing an inverse Fourier optical system. In FIG. 6, reference numeral 20 denotes a sample chamber having a rectangular shape in plan view, for example, and its periphery is surrounded by side walls 20a to 20d made of a material having a function of blocking external light. And, on the 45 ° diagonal line of the pair of side walls 20a, 20c, an optical window 21 as an optical compensator made of a light transmissive material,
22 is formed.

Then, the light source 1 and the condenser lens 3 face the other optical window 22 through the one optical window 21 diagonally below the one optical window 21, that is, the light source 1,
Condensing lens 3, one optical window 21 and the other optical window 2
2 are arranged in this order so as to be lined up on one straight line 23. Further, the front detector 5 faces the one optical window 21 through the other optical window 22 diagonally above the other optical window 22, that is, the front detector 5 and the other optical window 22.
And one of the optical windows 21 is arranged in this order as the straight line 23.
It is arranged so as to line up. That is, the light source 1, the condenser lens 3, the one optical window 21, the other optical window 22 and the front detector 5 are arranged so as to be aligned on one straight line 23 inclined by 45 °.

The focused laser beam 4 which is located on the one straight line 23 and which emits the light source 1 and which has passed through the condenser lens 3 is incident on the inside of the sample chamber 20 at 45 °. Thus, the rectangular parallelepiped sample cell 6 is provided. More specifically, the side 6a of the sample cell 6 in the irradiation light transmission direction is provided in parallel with the pair of side walls 20a, 20c, and the side 6b in the width direction is provided in parallel with the other pair of side walls 20b, 20d. Has been. That is, the sample cell 6 is provided in a state in which the center line CL is inclined at 45 ° with the one straight line 23 inclined at 45 °. Wide-angle scattered light detector groups 8 and 9 are provided on the side walls 20b and 20d on both sides of the sample cell 6, respectively.

In this embodiment, the optical windows 21 and 22 are connected to the optical axis (the line indicated by reference numeral 23 in the figure).
With respect to the optical axis 23, that is, the sample cell 6 tilted backward (on the side of the light source 1) by 45 ° is tilted in the opposite direction, that is, tilted forward (on the side of the front detector 5) by 45 °. By doing so, these optical windows 21 and 22 function as an optical compensator for converging the scattered light generated in the sample cell 6 and incident on the front detector 5 on the light receiving surface 5a of the front detector 5. In this case, the thickness of the optical windows 21 and 22 in the light transmission direction is appropriately set so that the total thickness thereof is optimal for converging the laser light on the light receiving surface 5a of the front detector 5. Of. In the particle size distribution measuring device configured as described above, the astigmatism caused by the incident irradiation light on the sample cell 6 in an oblique direction is eliminated, and the adverse effect on the measurement data can be eliminated.

That is, in the particle size distribution measuring apparatus of the second aspect of the invention, the deviation of the light beam caused by the incident incident light on the sample cell 6 in the oblique direction is opposite to the inclination direction of the sample cell 6 by a predetermined angle. It is corrected by the optical compensators 21 and 22 provided in a tilted state.

Then, according to the configuration shown in FIG.
Since the advantage of the inverse Fourier optical system that a long focal length can be secured as the condenser lens 3 can be enjoyed 100%, it goes without saying that the effect described in the above paragraph 0020 is exerted.

Further, in FIG. 6 described above, the optical compensators 21 and 22 are also used as optical windows in the sample chamber 20 in which the sample cell 6 and the wide-angle scattered light detector groups 8 and 9 are accommodated. It is not limited to this,
It can be variously modified and implemented, and when the intensity of the laser light 2 of the laser light source 1 is too strong, N for dimming is applied.
A D (neutral density) filter may be used as an optical compensator. When the laser light 2 has a plurality of wavelengths or when a white light source is used instead of the laser light source, a bandpass filter for wavelength selection may be used as an optical compensator. Good.

Furthermore, as shown in FIG. 7, wedge-shaped prisms 21A and 22A may be used as an optical compensator, or an appropriate lens may be used. When a lens is used as the optical compensator, it is not necessary to set its installation angle so as to form 90 ° with the center line CL of the cell 6. This is because when the optical compensator has a flat plate shape, the center line C of the sample cell 6 is used to remove the aberration.
It must be provided so as to form an angle of 90 ° with L, but if the optical compensator is not flat, aberration can be removed regardless of the installation angle. When the optical compensator has a flat plate shape, the aberration can be removed with a simpler configuration.

Further, as shown in FIG. 8, only the sample cell 6 may be housed in the sealed housing chamber 24. In this case, the housing chamber 24 needs to be formed of a material that allows light such as laser light to pass through well. By providing the sample cell 6 in a closed space such as the sample chamber 20 and the storage chamber 24, more stable measurement can be performed.

In the embodiments shown in FIGS. 6 to 8, the two optical compensators 21, 22 (21A, 22) are arranged on the optical axis between the condenser lens 3 and the front detector 5.
A, 21B, 22B) are provided, but it is not necessary to do so, and only one optical compensator may be provided at any position on the optical axis.

Also in the second invention provided with the plate-like optical compensator, the inclination angle θ of the sample cell 6 with respect to the optical axis 23 is not limited to 45 °, and the angle θ is, for example, 25 °. The angle may be set to any angle from ° to 65 °. In this case, the inclination angle θ of the sample cell 6 and the optical compensators 21, 22 (21A, 2
2A, 21B, 22B) and the inclination angle θ '
It is set so that + θ ′ = 90 °. For example, when the sample cell 6 is tilted backward by 30 °, the optical compensators 21, 22 (21A, 22A, 21B, 22B) need to be tilted forward by 60 °.

[0040]

As described above, according to the particle size distribution measuring apparatus of the present invention, it is possible to reliably detect scattered light with a scattering angle of around 90 °, and it is possible to detect scattered light of around 0 ° to 180 °. It is possible to reliably detect scattered light in a wide angle range,
The particle size distribution over a wide particle range can be measured with good reproducibility.

According to the invention described in claim 3,
In the particle size distribution measuring device employing the inverse Fourier optical system, the astigmatism caused by the irradiation light incident on the sample cell in the oblique direction is eliminated, and the adverse effect on the measurement data can be eliminated.

[Brief description of drawings]

FIG. 1 is a diagram schematically showing an example of a configuration of a particle size distribution measuring device according to a first invention.

FIG. 2 is a diagram showing an example of an optical system of the particle size distribution measuring device.

FIG. 3 is a diagram showing another example of the optical system.

FIG. 4 is a diagram showing still another example of the optical system.

FIG. 5 is a diagram showing still another example of the optical system.

FIG. 6 is a diagram schematically showing an example of the configuration of a particle size distribution measuring device according to a second invention.

FIG. 7 is a diagram schematically showing another example of the configuration of the particle size distribution measuring device.

FIG. 8 is a diagram schematically showing still another example of the configuration of the particle size distribution measuring device.

FIG. 9 is a diagram for explaining a conventional technique.

FIG. 10 is a diagram for explaining a conventional technique.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Light source, 3 ... Condensing lens, 4a, 4b ... Optical axis, 5 ... Front detector, 5a ... Light receiving surface, 6 ... Sample cell, 8, 9 ... Wide angle scattered light detector group, 10 ... Detector, 21 , 21A, 21
B, 22, 22A, 22B ... Optical compensator, 2
3 ... Optical axis.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Takuji Kurozumi             2 Higashimachi, Kichijoin-miya, Minami-ku, Kyoto-shi, Kyoto             HORIBA, Ltd. F term (reference) 2G059 AA03 AA05 BB06 BB09 BB13                       CC19 EE01 EE02 GG01 JJ11                       KK03 MM01 MM09 MM10 PP04

Claims (4)

[Claims] 1. A light source, a sample cell irradiated with light from the light source, a condenser lens arranged on the optical axis of the light, a transmitted light and a predetermined scattered light generated in the sample cell are detected. In the particle size distribution measuring apparatus with a front detector to be provided, the sample cell is provided in a state of being inclined with respect to the optical axis of the light emitted from the light source, and a plurality of detectors are provided on both sides of the sample cell. An apparatus for measuring particle size distribution, characterized in that a wide-angle scattered light detector group is provided. 2. The particle size distribution measuring device according to claim 1, wherein a condenser lens is provided between the light source and the sample cell, and a front detector is provided at a focal position of the condenser lens. 3. An optical compensator for converging transmitted light or scattered light on the light receiving surface of the front detector is provided at any position on the optical axis between the condenser lens and the front detector. The particle size distribution measuring device according to claim 2, wherein 4. The particle size distribution measuring device according to claim 1, wherein a condenser lens is provided between the sample cell and the front detector, and the front detector is provided at a focal position of the condenser lens.