JP3258890B2 - Scattering type particle size distribution analyzer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of irradiating a sample with light, detecting scattered light at that time with a photodetector, and measuring a particle size distribution in the sample based on a scattered light intensity pattern obtained thereby. The present invention relates to a scattering type particle size distribution measuring device.

[0002]

2. Description of the Related Art FIG. 2 shows a main part of a general scattering type particle size distribution measuring apparatus. In this figure, reference numeral 1 denotes a laser tube which emits a laser beam 2, and 3 denotes a beam which expands the laser beam 2 appropriately. Magnifier 4, a cell for housing sample 5, 6 a condenser lens provided behind cell 4, 7 a photodetector comprising a photodiode for detecting scattered light from condenser lens 6,
8 is a multiplexer for taking in the signal from the photodetector 7;
9 receives a signal from the multiplexer 8 and performs a calculation based on the scattered light intensity pattern to obtain a particle size distribution.
PU.

In the scattering type particle size distribution measuring device,
When the sample 5 is accommodated in the cell 4 and the laser light 2 is irradiated on the sample cell 4, a part of the laser light 2 irradiates the particles in the sample 5 in the cell 4 to become scattered light 10, and the remaining The light passes between the particles and becomes transmitted light 11. And
Both the scattered light 10 and the transmitted light 11 reach the photodetector 7 via the condenser lens 6.

As shown in FIG. 3, the photodetector 7 for detecting the scattered light 10 and the transmitted light 11 is generally formed so as to have a fan shape of approximately 90 ° in plan view. Used. That is, a transmitted light measurement detecting unit 12 for detecting the transmitted light 11 is formed in a main part of a sector of one detection plane (in this case, a paper surface). The scattered light receiving elements 13a, 13b, 13c,..., Which are concentrically arranged as a center, have a plurality of arc shapes for detecting the scattered light 10, and become wider as the distance from the transmitted light measurement detection unit 12 increases.
A scattered light detection measurement section 13 made of 13n is provided via an isolation gap.

[0005]

In the scattering type particle size distribution measuring device, an angular distribution sequence of the intensity of the scattered light 10 is measured, and the CPU 9 performs a particle size distribution calculation to display the particle size distribution. This particle size distribution calculation solves a friendholm-type integral equation of the first kind as shown in, for example, Japanese Patent Publication No. 7-85052, but it is very difficult to obtain the solution. If the data series of the angular distribution to be measured is different, the particle size distribution changes. To obtain the same result with the same sample, it is necessary to use another measuring device of the same data series.

However, conventionally, as shown in FIG. 3, the transmitted light measuring detecting section 12 is provided on one measuring surface, and the transmitted light measuring detecting section 12 is centered in one radial direction. Since only the scattered light detection measuring unit 13 including the plurality of scattered light receiving elements 13a to 13n is provided, it is necessary to use a plurality of scattering particle size distribution measuring devices to obtain an angular distribution series having different light intensities. Was. This is because there is no compatibility between measurement data in which the focal length f of the lens 6 and the width (hereinafter, simply referred to as “width”) of the plurality of scattered light receiving elements 13a to 13n in the scattered light detection measurement unit 13 are different. It is.

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above-described circumstances, and has as its object to simultaneously obtain a plurality of angular distribution data of different light intensities without using a plurality of photodetectors or devices. It is an object of the present invention to provide a scattering type particle size distribution measuring device which can be used.

[0008]

In order to achieve the above object, the present invention provides a method of irradiating a sample with light.
Scattered light is detected by a photodetector, and the resulting scatter
Measures particle size distribution in samples based on light intensity pattern
In the scattering type particle size distribution measuring device, the photodetector and
Then, on one detection plane, one radius around the optical axis
Scattering with multiple arc-shaped scattered light receiving elements arranged in the direction
Along with arranging a measurement unit for light detection,
In a different radial direction, the scattered light detection
A plurality of arc-shaped scattered light receiving elements with different width dimensions
Using the arrangement of another scattered light detection measurement unit arranged in a line
To obtain multiple angular distribution data of different light intensity at the same time
It is configured in. That is, in this invention, one detection plane, around the detector for transmitted light measurement, in different radial directions, relatively is provided a plurality of scattered light detecting measuring unit including a plurality of scattered light receiving elements diameter With a large range of particles
Simultaneously with particles in a relatively small range under the same test conditions
Ru configuration and tear to detect the original.

[0009]

In the present invention, a sample is irradiated with light, the scattered light at that time is detected by a photodetector, and the particle size distribution in the sample is measured based on the scattered light intensity pattern obtained thereby. In the scattering type particle size distribution measuring apparatus, as the photodetector, a plurality of arc-shaped scattered light receiving elements are arranged on one detection surface in one radial direction around the optical axis. Place the part,
In the radial direction different from the radial direction, the scattered light detection measurement unit and another scattered light detection measurement unit in which a plurality of arc-shaped scattered light receiving elements having different radial widths are arranged. Obtain angular distribution data of multiple different light intensities simultaneously
Ru configuration and tear as.

In this case, one scattered light detection measurement unit and another scattered light detection measurement unit may be arranged so as to have a point-symmetric positional relationship.

According to the present invention, a plurality of angular distribution data of different light intensities can be obtained at the same time, and it is not necessary to use a plurality of photodetectors or devices.

[0012]

Embodiments will be described with reference to the drawings. The scattered particle size distribution measuring apparatus of the present invention is significantly different from the conventional scattered particle size distribution measuring apparatus in that a plurality of scattered light detecting measuring units each including a plurality of scattered light receiving elements are provided on one detection plane. It is.

FIG. 1 schematically shows an example of a planar configuration of a photodetector 20 used in the scattering type particle size distribution measuring apparatus of the present invention. In FIG. The transmitted light measurement detection unit is the same as that indicated by reference numeral 12 in FIG. Reference numerals 22 and 23 denote scattered light detection measurement units provided on one detection plane (paper surface in this embodiment) including the transmitted light measurement detection unit 21, and are arranged so as to have a point-symmetric positional relationship with each other.

That is, one of the measuring units 22 for detecting scattered light
Is provided with a plurality of scattered light receiving elements 22a, 22b, 22c,... Around a transmitted light measuring detection unit 21 via an isolation gap 24, for example, a scattered light for detecting a focal length f of 100 mm. It is configured as a light detection measurement unit. Then, the other scattered light detection measurement unit 23 provided at a point symmetrical position with respect to the scattered light detection measurement unit 22
Has a plurality of scattered light receiving elements 23a, 23b, 23c,... Provided concentrically via an isolation gap 25 around a transmitted light measuring detection unit 21. It is configured as a light detection measurement unit.

That is, the width of the scattered light receiving elements 23a, 23b, 23c,.
The scattered light receiving element 22 of the corresponding scattered light detection measurement unit 22
a, 22b, 22c,..., and the width of the isolation gap 25 is also set to half of the width of the isolation gap 24. In each of the scattered light detection measurement units 22 and 23, the transmitted light measurement detection unit 2 is used.
The width increases as the distance from 1 increases, and both change rates change, for example, logarithmically.

In the scattering type particle size distribution measuring apparatus incorporating the photodetector 20 having the above configuration, the focal length f is 100 mm.
1 μm to 100 μm by the measuring unit 22 for detecting scattered light.
The scattered light due to the particles having a particle diameter of 0 μm can be detected, and the scattered light having a focal length of 50 mm can be detected by the scattered light detection measurement unit 23 having a diameter of 0.1 μm to 300 μm. That is, particles in a relatively large range and particles in a relatively small range can be simultaneously detected under the same test conditions.

In the above-described embodiment, the two measuring units 22 and 23 for detecting scattered light are arranged at point-symmetric positions with respect to the detecting unit 21 for measuring transmitted light. Although three or more detection measurement units may be provided, as in the embodiment, two scattered light detection measurement units 22,
23 is the simplest.

[0018]

The present invention is embodied in the above-described embodiment and has the following effects.

Conventionally, a plurality of scattering type particle size distribution measuring devices have been used in order to obtain compatibility of angle distribution data of light intensity. However, according to the present invention, desired measurement can be performed by using only one measuring device. Can be performed, and a process of converting data to match data of another measurement device is not required.

[Brief description of the drawings]

FIG. 1 is a diagram schematically showing a configuration of a photodetector used in the present invention.

FIG. 2 is a diagram schematically showing a general configuration of a scattering type particle size distribution measuring device.

FIG. 3 is a diagram schematically showing a configuration of a photodetector used in a conventional scattering type particle size distribution measuring device.

[Explanation of symbols]

2: light, 5: sample, 10: scattered light, 11: transmitted light, 20
... Photodetector, 21... Transmitted light measuring detector, 22. Scattered light detecting measuring unit, 22 a, 22 b, 22 c. Scattered light receiving element, 23. Scattered light detecting measuring unit, 23 a, 23 b, 23
c: Scattered light receiving element.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G01N 15/02 G01N 21/47

Claims (2)

(57) [Claims] 1. A scattering particle size distribution measuring device for irradiating a sample with light, detecting scattered light at that time with a photodetector, and measuring a particle size distribution in the sample based on a scattered light intensity pattern obtained thereby. In the device, as the photodetector, in one detection plane, in one radial direction around the optical axis, and arranged a measurement unit for scattered light detection arranged a plurality of arc-shaped scattered light receiving elements, In the radial direction different from the radial direction, another scattered light detection measurement unit in which a plurality of arc-shaped scattered light receiving elements having different widths in the radial direction from the scattered light detection measurement unit are arranged. multiple by using the
Angular distribution data of different light intensities can be obtained simultaneously
Configured scattering particle size distribution measuring apparatus according to claim tare Rukoto. 2. The scattering type particle size distribution measuring apparatus according to claim 1, wherein one scattered light detection measurement unit and another scattered light detection measurement unit are arranged so as to have a point-symmetric positional relationship.