KR101801087B1 - Particle measuring apparatus using light scattering - Google Patents

Abstract

The present invention relates to a particle measuring device using light scattering. According to the present invention, the particle measuring device collects weak scattered light to a large solid angle to be evenly concentrated to a small circular area in a measuring area where the particles are dispersed. Specifically, the particle measuring device has a groove on an outer side of a chamber (10) or a path penetrating the chamber (10) to form the measuring area where a fluid having the dispersed particles pass through, measures the scattered light by irradiating light to the measuring area, and measures the particle concentration by converting a signal of the measured scattered light to the particle concentration. The particle measuring device includes: a light source which irradiates the light to the measuring area; a collecting lens which faces an irradiation direction of the light on the opposite side of the light source with reference to the measuring area to refract and collect the scattered light; a plane mirror which is spaced apart from the collecting lens in an inclined manner on the backside of the collecting lens located on the opposite side of the light source to reflect the scattered light refracted by the collecting lens and transmit the light irradiated from the light source; and a light detector which is installed on a location where the scattered light reflected from the plane mirror is concentrated to measure the signal of the scattered light by the particles. Accordingly, the particle measuring apparatus is capable of measuring the particles with low concentration.

Description

[0002] Particle measuring apparatus using light scattering [

The present invention relates to a particle measuring apparatus using light scattering, and more particularly, to a particle measuring apparatus using light scattering, and more particularly, to a particle measuring apparatus using light scattering in which a particle is dispersed in a measuring region To a particle measuring apparatus using light scattering.

An in-situ particle measuring device installed to measure the concentration of particles in a region where particles are dispersed and flow, such as piping in a process of handling a chimney or powder that discharges flue gas or a chemical reaction chamber Light extinction, light scattering, and turbidity are used as a method of using light in the case of a light source. Among these methods, light scattering method is mainly used for measuring low concentration of particles.

In the conventional light scattering method, only a lens is used to focus scattered light, or a curved mirror is used. Light scattering signals by particles are most prominent at the opposite side of the irradiated beam (forward scattering) A light condensing mechanism is installed.

In this connection, Korean Patent No. 10-1132406 (registered on March 26, 2012, hereinafter abbreviated as "Patent Document 1") discloses a technique relating to a light scattering type particle measuring apparatus.

According to Patent Document 1, a reflection mirror is attached to a measurement chamber to increase the amount of scattered light received by the photodetector, and the reflected scattered light from the reflection mirror does not pass through the focal region of the incident light, It is possible to measure particles of a relatively smaller size by increasing the measured value, thereby reducing measurement errors due to noise, and preventing interference with the reflected scattered light generated by the particles in the focus region where the flow of particles is concentrated Thereby providing accurate and reliable measurement results.

However, in such a conventional light scattering particle measuring apparatus, the intensity of light to be irradiated may be lowered with time, and optical alignment may be changed by a change in vibration or temperature, and an optical system such as a lens, a mirror, The parts are contaminated by pollutants such as dust, and the intensity of the scattered light may be changed, so that it is necessary to correct the measured value.

In order to calibrate these measured values, a method of measuring the intensity of the scattered light by converting the intensity of the scattered light to the intensity of the irradiated light by constructing a mechanism that directly measures the irradiated light with the light sensing device May be used.

Another known method of calibrating the measured values is to supply the particles with known concentration to the measuring area and calibrate them by measuring the scattered light or by using a diffuser which knows the scattering characteristics instead of the particles, It is sometimes necessary to calibrate the measured scattered light.

On the other hand, in order to correct the fact that the background light other than the scattered light introduced from the measurement region is condensed and measured, conventionally, only the scattered light measurement signal by the irradiation light is extracted using the background light as the base .

In addition, since the performance of the particle measuring apparatus is deteriorated due to the contamination of the optical devices due to the fluid supplied to the measurement region, in order to prevent this, And a partition having holes through which irradiation light or scattered light can be transmitted are installed and a clean fluid is pushed through the holes to the measurement area to prevent contaminants from flowing into the measurement area.

On the other hand, when only an existing lens is used for focusing the scattered light, the lens is installed at a position deviated from the path of the irradiation light, in order to focus the scattered light except for the irradiated light. In this case, there is a limit in collecting the forward scattered light with a geometrically large solid angle.

As another example, there is a method of condensing scattered light using a curved mirror. For example, US Patent No. US 8134706 (registered on Mar. 13, 2012, hereinafter referred to as Patent Document 2) A technique for monitoring a monitor for monitoring particles in a stack is known.

According to Patent Document 2, scattered light is condensed by using a perforated mirror, and scattered light is reflected by a hole-shaped mirror to be concentrated. When such a hole mirror is used, the light beam and the stray light near the light source can be effectively passed through the hole. However, since the curved mirror must have a certain angle with the irradiated ray, this angle causes the scattered light to be projected in the form of an ellipse elongated in the direction of the angle. Here, in order to have a large solid angle, the angle between the mirror and the irradiated light becomes larger as the curved mirror is brought closer to the mirror. Therefore, it was necessary to condense the forward scattered light into a narrow region with a large solid angle to enable measurement of a small scattered light.

In addition, when the scattered light is reflected by the mirror having the hole, the scattered light reaching the hole portion of the mirror is not concentrated, so that the projected image of the light becomes a donut shape in which the central region is empty near the position where the scattered light is concentrated, Scattered light concentrated around the sensing part of the sensing device may be deviated. This may cause a phenomenon in which concentrated scattered light can not be effectively transmitted to the sensing unit. Therefore, a means for transferring concentrated scattered light to the sensing unit relatively uniformly was required.

On the other hand, the conventional method of directly measuring irradiated light as a method of correcting the light scattering measurement value uses a different optical path from that of the scattering light, so that the alignment of the optical device on the scattering light measurement path is changed There is a drawback that it can not be corrected. Conventional methods of supplying particles to the measurement region to compensate for such light scattering measurement values are difficult to apply in the industrial measurement field due to the additional necessity of a particle generator of a certain concentration, It is difficult to apply a diffuser to an industrial measurement site rather than a laboratory. Therefore, in order to install and use the particle measuring device in the industrial field, it was required to have a mechanism that is periodically driven automatically and installed in a position isolated from the pollution source, so that the measured value can be corrected.

On the other hand, in the conventional case using a pulsed light source in order to block most of the background light introduced from the measurement region, if the intensity of the background light is not sufficiently small compared to the intensity of the scattered light of the particle, The measurement range of the concentration of the particles can be reduced or the accuracy of the measured value is reduced. Therefore, in this case, a device capable of effectively blocking the incoming background light was needed.

On the other hand, if the optical devices are contaminated by contaminants introduced from the measurement area, the performance of the measuring device is deteriorated. Therefore, in order to prevent this, there has been a need for an effective structure of a pollution prevention device for preventing the optical devices from being contaminated by contaminants that may enter from the measurement area.

Korean Registered Patent No. 10-1132406 B1 2012.03.26. Enrollment US registered patent US08134706 Registration March 13, 2012

SUMMARY OF THE INVENTION Accordingly, the present invention has been made in an effort to solve the above problems, and it is an object of the present invention to provide a condenser lens in close proximity to a scattering region of a particle in the direction of irradiation of light, A planar mirror having a hole in the back and forth direction is inclined at a predetermined angle with respect to the irradiation direction so that the forward scattered light is condensed at a large solid angle by the condenser lens and the irradiated light and the ambient light coming from the light source are passed through the hole The scattered light except for the scattered light in the hole direction is reflected by the plane mirror so as to be concentrated in a small area in a circular shape so that the weak scattered light is focused on the optical signal measuring part of a small area with a large solid angle, And to provide a particle measuring apparatus using light scattering enabling measurement.

 Another object of the present invention is to provide an optical waveguide and a scattered light diffuser in a region where scattered light is concentrated between a light sensing device and a plane mirror to transmit scattered light relatively uniformly to a sensing unit of a light sensing device, And to provide a particle measuring apparatus using light scattering capable of improving the measurement stability of the particle.

Another problem to be solved by the present invention is to provide a narrow band-pass filter in front of the light sensing device to block the background light, so that a weak light scattering phenomenon The present invention also provides a particle measuring apparatus using light scattering that can have a wide measuring range and improve the precision of measurement.

It is another object of the present invention to provide an apparatus and a method for detecting a pollutant by providing at least one light diffuser that is periodically and automatically driven in a region protected from pollutants near a measurement region, And it is an object of the present invention to provide a particle measuring apparatus using light scattering which enables a signal of a scattered light to be automatically corrected in an industrial field.

Another problem to be solved by the present invention is to provide an apparatus and a method for measuring a distance between a first plate of a chamber partition and a second plate of a chamber partition, A part of the porous material is made of a porous material so that the clean fluid can be discharged to prevent contaminants from flowing into the measurement area and thereby to prevent degradation of the performance of the measuring device due to contamination of the optical device. And to provide a particle measuring apparatus.

According to a first aspect of the present invention for attaining the above object, there is provided a method of manufacturing a semiconductor device, comprising: forming a groove on the outside of the chamber or forming a passage through the inside of the chamber, An apparatus for measuring a concentration of a particle by irradiating a measurement region with a light beam and measuring scattered light by the particle and converting the measured scattered light signal into a particle concentration, the apparatus comprising: a light source for irradiating a light beam to a measurement region; A condensing lens installed to face the irradiation direction of the light beam on the opposite side of the light source to refract and condense the scattered light, a reflecting mirror disposed at a rear side of the condensing lens opposite to the light source so as to be spaced apart from the condensing lens to reflect scattered light refracted by the condensing lens, A plane mirror with a hole through which the irradiated light beam passes, a position where the scattered light reflected from the plane mirror is concentrated A particle measuring apparatus using a light scattering comprising an optical sensing device for measuring a scattered light signal by the control particles.

In order to achieve the above object, the second embodiment of the present invention is a particle measuring apparatus using light scattering, further comprising an optical waveguide provided between a position where the scattered light is concentrated and scattered light concentrated between the light sensing devices.

Each of the embodiments of the present invention may further be embodied as another embodiment including scattered light diffracters provided in a region where scattered light between the light sensing device and the plane mirror is concentrated and scattering concentrated scattered light.

Each of the embodiments of the present invention further includes a narrow band pass filter which is provided between the light sensing device and the plane mirror to filter wavelengths other than the wavelength of the laser light, . ≪ / RTI >

Each of the above-described embodiments of the present invention includes a clean fluid supply device for supplying a clean fluid into a chamber, a first hole formed through the first hole for passing a light beam therethrough and a part of a body of the chamber, A first partition for passing the first fluid through the first partition, a first partition for passing the cleaned fluid through the first partition, a second partition provided between the light source and the first partition so as to be spaced apart from the first partition by a predetermined distance, A light diffuser, and a rotatable disc body, and a light diffuser is supported and fixed inside the disc body so that the light diffuser is positioned on a surface facing the light beam in the direction of irradiation of the light by a rotation operation of the disc body. A switching plate driving device for driving the rotation of the switching plate, a second hole formed so as to allow scattered light to pass therethrough, A second partition provided between the fixed region and the condenser lens to allow the scattered light to pass through the second hole, a condenser lens provided inside the second partition to surround the second hole, the condenser lens being fixed to the inner peripheral surface of the body, Each of which is provided with a porous portion, which can be made of a metal, and each can be embodied in another embodiment.

According to the present invention, since the condenser lens is disposed close to the scattering region of the particle in the irradiation direction of the particle and the plane mirror having the hole formed in the rear of the condensing lens in the irradiation direction of the light beam is provided at a predetermined angle to the irradiation direction The scattered light except the scattered light in the direction of the hole is reflected by the plane mirror so that the forward scattered light can be collected by the condensing lens into a large solid angle by the condenser lens, It is possible to concentrate scattered light to a small area circularly by the plane mirror, and therefore, it is advantageous to condense weak scattered light into a small area optical signal measuring part with a large solid angle to enable low concentration particle measurement .

According to the present invention, since the optical waveguide and the scattered light diffuser are installed in the region where the scattered light between the light sensing device and the plane mirror is concentrated, the scattered light can be transmitted to the sensing portion of the light sensing device relatively uniformly, . ≪ / RTI >

According to the present invention, since a narrow band pass filter is provided in front of the light sensing device, it is possible to block background light, so that a laser light source can be used. Thus, a wide measurement range can be obtained even for weak scattered light with low particle concentration. It is possible to improve the precision of the measurement.

Further, according to the present invention, since the switching plate including the at least one light-emitting device that is periodically and automatically driven in the area protected from the contaminant near the measuring area and the driving device are provided, To be corrected.

According to the present invention, a part of the barrel attached so as to surround the condenser lens and the second hole of the chamber partition at the rear of the measurement area is made porous by separating the switching plate in front of the measurement area and the first hole of the chamber partition, So that contaminants can be prevented from flowing into the measurement area, thereby preventing deterioration of the performance of the measuring device due to contamination of the optical device.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view schematically illustrating a particle measuring apparatus using light scattering according to a preferred embodiment of the present invention. FIG.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the structure and operation of a particle measuring apparatus using light scattering according to a preferred embodiment of the present invention and its operation and effect will be described in detail with reference to the accompanying drawings.

It is to be understood that the words or words used in the present specification and claims are not to be construed in a conventional or dictionary sense and that the inventor can properly define the concept of a term in order to describe its invention in the best possible way And should be construed in light of the meanings and concepts consistent with the technical idea of the present invention. Therefore, it should be understood that the embodiments described herein and the configurations shown in the drawings are only the most preferred embodiments of the present invention, and that various equivalents and modifications may be substituted for them at the time of the present application shall.

FIG. 1 is a cross-sectional view schematically illustrating an overall configuration of a particle measuring apparatus using light scattering according to the present invention. The particle measuring apparatus using light scattering according to the present invention includes a light source 21, a condenser lens 22, a flat mirror 23 And / or light scattering photodetector 26, and / or narrow band pass filter 27 may be configured as optional, including optical sensing device 24 and optical sensing device 24, and optical waveguide 25 and / And may be implemented in different embodiments.

Further, the particle measuring apparatus using light scattering according to each embodiment of the present invention may further include the light beam radiator 28, the switching plate 29, and the switching plate driving device 30 so as to be implemented in another embodiment Each of these embodiments may further be embodied in another embodiment including the clean fluid supply device 32, the first partition 11, the second partition 12, and the barrel 33.

The particle measuring apparatus according to each of the embodiments of the present invention as described above can form a groove on the outside of the chamber 10 or form a passage through the inside of the chamber 10 so that the particles are dispersed in the space And a measurement region 13 through which the fluid can pass. By irradiating the measurement region 13 with a light beam, the scattered light by the particles of the fluid is measured, the measured scattered light signal is converted into the concentration of the particles, For example.

The measurement region 13 provided in the chamber 10 is formed inside the space surrounded by the first partition 11 and the second partition 12 provided on the wall surface of the chamber 10 as shown in FIG. The first partition 11 and the second partition 12 form a part of the body of the chamber 10 facing each other.

The first partition 11 is formed with a first hole 11a through which the light 21a irradiated from the light source 21 passes and a second hole 11a provided between the light source 21 and the measurement region 13, 1 hole 11a.

The second partition 12 is provided with a second hole 12a through which the scattered light by the particles passes and is provided between the measuring area 13 and the condenser lens 22 so as to scatter the scattered light by the particle into the second hole 12a .

The light source 21 is installed outside the chamber 10 so as to irradiate a light ray 21a to the measurement region 13 through the inner space of the chamber 10 and a laser can be used as the light source 21. [ have.

1, the condensing lens 22 is provided near the opposite side of the light source 21, that is, the rear side of the scattering region of the particle with respect to the measurement region 13, And refracts and condenses the small scattered light due to the particles with a large solid angle.

The planar mirror 23 is provided on the opposite side of the measurement region 13 with respect to the condenser lens 22 so as to be spaced from the condenser lens 22 and is inclined at a predetermined angle with respect to the irradiation direction of the light beam 21a, The scattered light refracted by the lens 22 is reflected so as to be concentrated in the optical signal measuring unit of the circular small area so that the measurement of the particles at a low concentration is enabled and the passage hole 23a is provided at the center portion, And passes the irradiated light ray 21a.

The light sensing device 24 is installed at a position where the scattered light reflected by the plane mirror 23 is concentrated, and measures the scattered light signal by the particle through the sensing part.

The optical waveguide 25 is provided between the position where the scattered light is concentrated by the plane mirror 23 and the light sensing device 24 and stably transmits the concentrated scattered light to the light sensing device 24. [

The scattered light diffractor 26 is installed in a region where scattered light is concentrated between the light sensing device 24 and the planar mirror 23, preferably between the light sensing device 24 and the optical waveguide 25, Scattering the scattered light transmitted through the optical waveguide 25 and transmitting the scattered light to the sensing unit of the light sensing device 24 relatively uniformly.

A narrow band pass filter 27, preferably using a laser as the light source and blocking off wavelengths outside the wavelength band of the light source, is provided between the light sensing device 24 and the planar mirror 23, preferably between the light sensing device 24 And the scattered light diffuser 26, and effectively filters the background light coming from the outside of the chamber.

The light diffuser 28 is arranged within the chamber 10 in front of the measurement area 13 in the direction of irradiation of the light 21a and preferably within the first partition 11 forming part of the measurement area 13 (Preferably a distance allowing a space for allowing a clear fluid to pass through) to be spaced apart from the first partition 11 by a predetermined distance, and the light 21a irradiated from the light source 21 is scattered . Such a light diffuser may be used to correct the signal of scattered light in an industrial field, and may be composed of more than one.

It is preferable that the switching plate 29 is formed of a rotatable disk body and is provided in an area protected from contaminants near the measurement area. The conversion plate 29 supports and fixes the light beam radiator 28 inside the disk body so that the light beam radiator 28 is rotated by the rotation of the disk body on the surface facing the irradiation direction of the light ray 21a To be positioned. The switching plate 29 is provided with a window capable of passing the light ray 21a through the measurement region 13 to one side of the disc body provided with the light beam radiator 28 and preventing the contaminants from flowing into the measurement region 13, (31) is installed and fixed so that one of the light beam expander (28) and the window (31) is selectively placed on the opposite surface in the irradiation direction of the light ray (21a) It is possible.

The switching plate drive device 30 drives the rotation operation of the switching plate 29 automatically or manually according to the set value. If it is automatically driven, it can be driven periodically according to the set value. Here, the switching plate drive device 30 may be constituted by either a motor or a cylinder driven by a fluid.

The clean fluid supply device 32 is configured to supply the clean fluid to the inside of the chamber 10.

The lens barrel 33 is formed of a cylindrical body having an inner diameter larger than the outer diameter of the focusing lens 22 so as to allow both ends to be opened and fixed to the inner peripheral surface of the focusing lens 22, A condenser lens 22 is fitted and fixed on the inner circumferential surface of the cylindrical body and a clean fluid is passed through the second partition 12 so as to surround the second hole 12a, A porous portion 33a is provided along the circumference of the cylindrical body. Here, the porous portion 33a may be formed of a plurality of circular holes or a porous material.

The operation and effect of the particle measuring apparatus using the light scattering according to the present invention will be described as follows.

The first partition 11 is located adjacent to the measurement region 13 and is located toward the light source 21 and has a first hole 11a through which the light 21a passes. And a second partition 12 having a second hole 12a which is adjacent to the light source 21 in the opposite direction and through which the light ray 21a and the scattered light can pass, A light source 21 for emitting a light ray 21a of the particle is placed outside the chamber 10, that is, on the front side of the measurement region 13 of the particle to be measured, A condenser lens 22 is provided using the lens barrel 33 so as to face the irradiation direction and a flat mirror 23 having a through hole 23a is provided behind the condenser lens 22. [ At this time, the plane mirror 23 is installed at a predetermined angle with the light ray 21a to be irradiated.

The optical sensing device 24 is installed at a position where the scattered light refracted by the condenser lens 22 and reflected by the plane mirror 23 is concentrated or an optical waveguide 25 is installed at this position A light sensing device 24 is provided at another location that transmits light, and the light intensity is measured by the light sensing device 24.

In this way, the intensity of the measurement light transmitted to the sensing unit of the light sensing device 24 can be increased by converging the forward scattered light to a narrow region of a large solid angle by using the condenser lens 22 and the planar mirror 23 .

The electrical signal converted by the light sensing device 24 is then converted to a particle concentration in the concentration converter.

In the present invention, when the scattering photodetector 26 is provided in the region where the scattered light between the photodetector 24 and the planar mirror 23 is concentrated, scattered light scattered by the scattered photodetector 26 is scattered The intensity of the light can be made uniform at the center of the scattered light so that the scattered light can be transmitted to the sensing unit of the light sensing device 24 without being concentrated at the center. Ideally, providing the scattering photodetector 26 between the photodetector 24 and the adjacent optical waveguide 25 is most effective because it minimizes the transmission loss of scattered light.

When the narrow band pass filter 27 is provided between the light sensing device 24 and the scattering photodetector 26 in the front of the photodetector 24 in the present invention as described above, The narrow band pass filter 27 filtering the wavelength band of the background light effectively blocks the background light, thereby lowering the base signal. Thus, since the background light is detected by the light sensing device 24 together with the scattered light, it is possible to prevent the measurement range of the concentration from being reduced or the accuracy of the density measurement value to be reduced.

In the present invention as described above, a switching plate 29 including at least one light beam expander 28 is provided between the first partition 11 and the light source 21, and the switching plate 29 is automatically Or the switching plate driving device 30 for manually driving the switching plate 29 so that the disk body of the switching plate 29 is rotated automatically or manually through the switching plate driving device 30 periodically, It is possible to periodically correct the signal of the scattered light by switching to be located on the surface facing the irradiation direction of the light source 21a. In this way, it is possible to easily correct the light scattering signal in the industrial field. A window 31 through which the light ray 21a is transmitted is additionally provided on the other side of the switching plate 29 so that when the light ray diffracting device 28 is not used, So that the inflow can be prevented.

In the present invention as described above, the switching plate 29 is provided so as to maintain a predetermined distance between the first holes 11a of the first partition 11, and the clean fluid It is possible to prevent the optical devices from being contaminated by contaminants introduced from the measurement area 13 through the first hole 11a of the first partition 11 do.

The lens barrel 33 including the condenser lens 22 is attached to the second partition 12 provided with the second hole 12a and the lens barrel 33 between the condenser lens 22 and the second hole 12a If a clean fluid is supplied from the clean fluid supply device 32 and discharged to the measurement area 13 through the porous part 33a after a part of the body is formed into a porous part 33a with small holes or a porous material, It becomes possible to prevent the optical devices from being contaminated by contaminants flowing from the measurement area 13 through the second hole 12a of the second partition 12. [ This makes it possible to prevent the optical device from being contaminated by contaminants introduced from the measurement area 13. [

Accordingly, it is possible to converge the forward scattered light to a large solid angle by the condenser lens, and concentrate the scattered light to be concentrated in a small circular area by the plane mirror, so that the weak scattered light is converted into the small- It is possible to collect the scattered light to the sensing part of the light sensing device relatively uniformly, thereby providing an advantage that the measurement stability of the particle measuring device can be improved.

Further, according to the present invention, it is possible to use a laser light source, so that measurement accuracy can be improved in a wide measuring range even for weak scattering light having low particle concentration. By using a conversion plate including one or more light- Thereby preventing the deterioration of the performance of the measuring apparatus caused by the contamination of the optical apparatus by preventing the contamination from flowing in the measuring region by using the clean fluid do.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, Modification is possible. Accordingly, it is intended that the scope of the invention be defined by the claims appended hereto, and that all equivalent or equivalent variations thereof fall within the scope of the present invention.

10: chamber 11: first partition
11a: first hole 12: second partition
12a: second hole 13: measuring area
21: light source 21a: ray
22: condenser lens 23: flat mirror
23a: Through hole 24: Light sensing device
25: optical waveguide 26: scattered light diffuser
27: Narrow band pass filter 28: Light ray diffuser
29: switching board 30: switching board driving unit
31: Window 32: Clean fluid supply device
33: barrel 33a: porous portion

Claims (9)

There is provided a measurement region 13 in which a groove is formed on the outside of the chamber 10 or a passage passing through the inside of the chamber 10 so that a particle-dispersed fluid can pass through the groove or the passage An apparatus for measuring the concentration of particles by irradiating a light beam onto the measurement region (13), measuring scattered light by the particles, and converting the measured scattered light signal into a particle concentration,
A light source 21 for irradiating the measurement region 13 with a light ray 21a;
A condenser lens 22 provided on the opposite side of the light source 21 with respect to the measurement region 13 so as to face the irradiation direction of the light beam 21a to refract and condense the scattered light;
The light source 21 reflects the scattered light refracted by the condenser lens 22 so as to be spaced apart from the condenser lens 22 in the rear of the condenser lens 22 on the opposite side of the light source 21, A plane mirror (23) having a hole (23a) through which said beam of light (21a) passes;
A light sensing device (24) installed at a position where scattered light reflected by the plane mirror (23) is concentrated and measuring a scattered light signal by the particle;
An optical waveguide (25) installed between the position where the scattered light is concentrated and the light sensing device (24) and transmitting the concentrated scattered light;
At least one light irradiator (28) installed in the chamber (10) in front of the measurement region in the direction of the light beam to scatter light rays (21a) emitted from the light source (21);
And the light beam expander 28 is supported and fixed inside the disc body so that the light beam expander 28 is moved in the radial direction of the light beam 21a in the opposite direction A switching plate (29) for switching to be located on a viewing plane;
A switching plate drive device (30) for driving the rotation of the switching plate (29);
A clean fluid supply device (32) for supplying a clean fluid into the chamber (10);
A first hole 11a is formed in the chamber 10 so as to allow the light beam 21a to pass therethrough and a part of the body of the chamber 10 is formed on the rear side of the switching plate 29 between the light source 21 and the measurement area 13, A first partition (11) installed to secure a space through which the clean fluid can pass between the first partition (11) and the switching plate (29) and to pass the light ray (21a) through the first hole (11a);
A second hole 12a is formed to allow the scattered light to pass therethrough and is formed between the measurement region 13 and the condenser lens 22 to form a part of the body of the chamber 10, A second partition (12) passing through the first partition (12); And
A porous portion 33a provided inside the second partition 12 so as to surround the second hole 12a and fixed to the inner circumferential surface of the body of the condenser lens 22 and through which the clean fluid can pass, And a lens barrel (33) provided with the lens barrel. delete The method of claim 1,
And a scattering photodetector (26) disposed in the region where the scattered light is concentrated between the light sensing device (24) and the plane mirror (23) and scattering the scattered light concentrated thereon. The particle measuring device used. The method of claim 1,
A laser is used as the light source 21,
And a narrow band pass filter (27) disposed between the light sensing device (24) and the plane mirror (23) for filtering wavelengths other than the wavelength of the laser light. Measuring device. delete 2. The apparatus according to claim 1, wherein the switching plate (29)
A window 31 through which a light ray 21a passes is installed and fixed to one side of a disc body provided with the light beam radiator 28 and the rotating body of the light ray radiator 28 and the window 31 So that any one of them is positioned on a surface facing the irradiation direction of the light ray (21a). The apparatus according to claim 1, wherein the switching plate drive device (30)
Wherein the particle is a cylinder driven by a motor or a fluid. delete 3. The device of claim 1, wherein the porous portion (33a)
Characterized in that a plurality of circular holes are formed or a porous material is used.

Images