JPH0226176B2 - - Google Patents
Info
- Publication number
- JPH0226176B2 JPH0226176B2 JP56016593A JP1659381A JPH0226176B2 JP H0226176 B2 JPH0226176 B2 JP H0226176B2 JP 56016593 A JP56016593 A JP 56016593A JP 1659381 A JP1659381 A JP 1659381A JP H0226176 B2 JPH0226176 B2 JP H0226176B2
- Authority
- JP
- Japan
- Prior art keywords
- sample gas
- gas flow
- particles
- nozzle
- sample
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 239000002245 particle Substances 0.000 claims description 25
- 238000000149 argon plasma sintering Methods 0.000 claims description 7
- 238000000034 method Methods 0.000 claims description 7
- 238000010438 heat treatment Methods 0.000 claims description 3
- 238000006243 chemical reaction Methods 0.000 claims description 2
- 230000002093 peripheral effect Effects 0.000 claims 3
- 238000001089 thermophoresis Methods 0.000 claims 1
- 239000000443 aerosol Substances 0.000 description 12
- 238000005259 measurement Methods 0.000 description 5
- 239000000428 dust Substances 0.000 description 4
- 230000003749 cleanliness Effects 0.000 description 3
- 230000003287 optical effect Effects 0.000 description 2
- 238000004378 air conditioning Methods 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N15/00—Investigating characteristics of particles; Investigating permeability, pore-volume or surface-area of porous materials
- G01N15/02—Investigating particle size or size distribution
- G01N15/0205—Investigating particle size or size distribution by optical means
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N15/00—Investigating characteristics of particles; Investigating permeability, pore-volume or surface-area of porous materials
- G01N15/06—Investigating concentration of particle suspensions
- G01N15/075—Investigating concentration of particle suspensions by optical means
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N30/00—Investigating or analysing materials by separation into components using adsorption, absorption or similar phenomena or using ion-exchange, e.g. chromatography or field flow fractionation
Landscapes
- Chemical & Material Sciences (AREA)
- Dispersion Chemistry (AREA)
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Investigating Or Analysing Materials By Optical Means (AREA)
Description
【発明の詳細な説明】
この発明は、光散乱式浮遊粒子計数方法、特に
試料エアゾルの熱泳動現象を利用して濃度偏倚を
生ぜしめる光散乱式浮遊粒子計数方法に関するも
のである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a light scattering suspended particle counting method, and more particularly to a light scattering suspended particle counting method that utilizes the thermophoretic phenomenon of a sample aerosol to generate a concentration deviation.
特別な除塵空調装置を設備したクリーンルーム
のような環境の空気清浄度を測定する場合、光散
乱式粒子計数装置が一般に使用されている。その
原理は、第１図に示すように、ビーム状の照射光
線Ｌ中にノズルＮから流出される測ろうとする試
料エアロゾルＳを通し、個々の粒子によつて散乱
された光を光電変換素子でとらえ、電気信号とし
て検出、計数するものであり、この場合の光学系
としては種々の構成でなるものが提案、実用され
ている。 Light scattering particle counters are commonly used to measure air cleanliness in environments such as clean rooms equipped with special dust removal air conditioning equipment. As shown in Figure 1, the principle is that a sample aerosol S to be measured flows out from a nozzle N into a beam-shaped irradiation light L, and the light scattered by individual particles is converted into a photoelectric conversion element. This is to detect and count the electrical signals as electrical signals, and optical systems with various configurations have been proposed and put into practice in this case.
ところで、超LSI製造工程のように、高度な空
気清浄度を要求される環境では、単位体積の空気
中の粒子数が極端に少ないので、検出した粒子数
が計測値として有意な数値、すなわち少くとも
100個に達するためには、大量の試料を装置に導
入する必要がある。このことから、試料空気を照
射領域Ｔに噴出するノズルＮの内径が一定で試料
空気の流速が不変とした場合、長い測定時間を必
要とすることとなり、短時間に測定時間を得よう
とすると高流速となつて層流状態が保てなくな
る。他の手段としてノズルＮの内径を大とすると
照射光線Ｌの幅も拡大しなければならない。すな
わち、ノズルＮの内径と略等しい試料空気流の値
径をWA、照射光線Ｌの幅をWLとした場合、粒子
を全て見逃がさずに検出するためにはWA＜WLで
なければならない。そのため強力な光源を用いな
ければ光束密度を保持することが困難となる。 By the way, in environments where a high degree of air cleanliness is required, such as in the VLSI manufacturing process, the number of particles in a unit volume of air is extremely small, so the number of particles detected is a significant value as a measurement value, that is, a small number. friend
To reach 100 samples, a large number of samples must be introduced into the device. From this, if the inner diameter of the nozzle N that jets the sample air into the irradiation area T is constant and the flow rate of the sample air is unchanged, a long measurement time will be required, and if you try to obtain a measurement time in a short time, The flow velocity becomes high and laminar flow cannot be maintained. As another means, if the inner diameter of the nozzle N is increased, the width of the irradiation light beam L must also be increased. In other words, if W A is the diameter of the sample air flow that is approximately equal to the inner diameter of nozzle N, and W L is the width of the irradiated light beam L, W A < W L must be satisfied in order to detect all particles without missing them. Must be. Therefore, it is difficult to maintain the luminous flux density unless a powerful light source is used.
この発明は、上述した問題を解消するものであ
る。すなわち、エアロゾルに温度勾配が存在する
と、媒質気体分子の運動エネルギーは高温側が低
温側より大きいので粒子への分子の衝突エネルギ
ーも高温側が大きく、粒子は低温側へ向かう力を
受ける。このような熱泳動現象を利用して空気中
に略均一に分散しているエアロゾル中の粒子を局
部集中（濃度偏倚）させ、光散乱式による高清浄
度空気の塵埃濃度測定において、短時間に大量の
試料エアロゾルについて測定できるようにした方
法を提供することを目的とするものである。 This invention solves the above-mentioned problems. That is, when a temperature gradient exists in an aerosol, the kinetic energy of the medium gas molecules is greater on the high temperature side than on the low temperature side, so the collision energy of molecules with particles is also greater on the high temperature side, and the particles receive a force directed toward the low temperature side. Utilizing this thermophoretic phenomenon, particles in aerosol, which are almost uniformly dispersed in the air, are locally concentrated (concentration biased), making it possible to quickly measure dust concentration in highly clean air using the light scattering method. The object of the present invention is to provide a method that allows measurement of a large amount of sample aerosol.
さらにこの発明の目的は、粒径0.1μｍ程度の極
微小な粒子検出に際して、照射領域内の気体分子
による散乱光が粒子による散乱光に近づき、測定
を困難にしている問題を解消するにある。 A further object of the present invention is to solve the problem that when detecting extremely small particles with a particle size of about 0.1 μm, the light scattered by gas molecules in the irradiation region approaches the light scattered by particles, making measurement difficult.
次に第２図の一実施例を用いて、この発明を説
明すると、試料気体流を形成する試料エアロゾル
Ｓを導入するノズルＮの一部または全部の周囲に
適宜の加熱体Ｈを取付け、ノズル管壁を環境温度
よりも高温に保ち、導入された試料エアロゾルＳ
中に軸対称状に温度勾配を与える。そうすると試
料気体流を構成する媒体気体分子のうち周縁部の
媒体気体分子の運動エネルギーを軸周辺部の媒体
気体分子の運動エネルギーより大きくさせること
により媒体気体分子の浮遊粒子への衝突エネルギ
ーを軸周辺部の衝突エネルギーより大きくさせ
る。その結果試料気体流に含まれている浮遊粒子
は試料気体流の軸周辺部に集められるような現象
（すなわち熱泳動現象）によつて軸周辺に濃縮さ
れる。こうして試料エアロゾルＳの軸中心に偏倚
された直径wAで示す部分STに照射光線を当てれ
ばよく、直径WAで示す試料流を照射する光量に
比べはるかに少ない光量で済むことになる。SA
は塵埃粒子を含まない試料エアロゾルの領域を示
す。したがつて光学系の構成が簡略化でき、光源
のパワー減少など利点は大きい。 Next, the present invention will be explained with reference to an embodiment in FIG. The sample aerosol S introduced by keeping the tube wall at a temperature higher than the ambient temperature
A temperature gradient is applied in an axially symmetrical manner. Then, among the medium gas molecules constituting the sample gas flow, the kinetic energy of the medium gas molecules at the periphery is made larger than the kinetic energy of the medium gas molecules around the axis, thereby reducing the collision energy of the medium gas molecules with floating particles around the axis. collision energy. As a result, suspended particles contained in the sample gas stream are concentrated around the axis of the sample gas stream due to a phenomenon in which they are collected around the axis of the sample gas stream (ie, a thermophoretic phenomenon). In this way, the irradiation light beam only needs to be applied to the portion S T of the sample aerosol S shown by the diameter w A that is offset from the axis center of the sample aerosol S , and the amount of light required is much smaller than the amount of light used to irradiate the sample flow shown by the diameter W A . S A
indicates the area of the sample aerosol that does not contain dust particles. Therefore, the configuration of the optical system can be simplified and the power of the light source can be reduced, which has many advantages.
また、粒径0.1μｍ程度の粒子の検出も、気体分
子による散乱光による障害を排除して正確になし
うる。 Furthermore, particles with a diameter of about 0.1 μm can be detected accurately by eliminating interference caused by light scattered by gas molecules.
以上のようにこの発明は、簡単な手段によつて
高度な清浄度を要求される環境における、および
極めて微細な粒子の検出を容易にするものであ
り、工業上の利益顕著である。 As described above, the present invention facilitates the detection of extremely fine particles in environments requiring a high degree of cleanliness by simple means, and has significant industrial benefits.
第１図は従来方法の原理を説明するための斜視
図、第２図はこの発明を説明するための一実施例
斜視図である。
Ｓ：試料エアロゾル、ST：軸中心に偏倚された
試料エアロゾル部分、SA：塵埃粒子を含まない
試料エアロゾル部分、Ｎ：ノズル、Ｈ：加熱体。
FIG. 1 is a perspective view for explaining the principle of a conventional method, and FIG. 2 is a perspective view of an embodiment for explaining the present invention. S: Sample aerosol, S T : Sample aerosol portion biased to the axial center, S A : Sample aerosol portion without dust particles, N: Nozzle, H: Heating element.
Claims (1)
せ、上記試料気体流内に浮遊粒子が含まれている
とき当該浮遊粒子によつて散乱された散乱光を光
電変換素子によつて電気信号に変換し、この電気
信号の変化に基づいて上記試料気体内に含まれて
いる浮遊粒子の数を計数する光散乱式浮遊粒子計
数方法において、 上記ノズルから流出させる上記試料気体流の周
縁部を加熱することにより上記試料気体流に対し
て軸対称状の温度勾配を与え、これにより上記試
料気体流を構成する媒体気体分子のうち当該周縁
部の媒体気体分子の運動エネルギーを軸周辺部の
媒体気体分子の運動エネルギーより大きくさせて
上記試料気体流の浮遊粒子を熱泳動によつて上記
軸周辺部に集め、上記軸周辺部に対して上記照射
光線を集光させる ことを特徴とする光散乱式浮遊粒子計数方法。 ２ 上記ノズルに加熱体を取り付けることにより
上記試料気体流の周縁部を加熱する ことを特徴とする光散乱式浮遊粒子計数方法。[Claims] 1. A sample gas flow is caused to flow out from a nozzle into an irradiation light beam, and when floating particles are included in the sample gas flow, scattered light scattered by the floating particles is transmitted to a photoelectric conversion element. In the light scattering suspended particle counting method, which converts the sample gas into an electrical signal and counts the number of suspended particles contained in the sample gas based on a change in the electrical signal, the sample gas flow is discharged from the nozzle. By heating the periphery of the sample gas flow, an axially symmetrical temperature gradient is applied to the sample gas flow. It is characterized by making the kinetic energy of the sample gas flow larger than the kinetic energy of the medium gas molecules in the peripheral part to collect the suspended particles in the sample gas flow around the shaft by thermophoresis, and converging the irradiation light beam on the peripheral part of the shaft. A light scattering suspended particle counting method. 2. A light scattering suspended particle counting method, characterized in that a peripheral portion of the sample gas flow is heated by attaching a heating element to the nozzle.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56016593A JPS57131036A (en) | 1981-02-06 | 1981-02-06 | Light scattering type floating particle counting |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56016593A JPS57131036A (en) | 1981-02-06 | 1981-02-06 | Light scattering type floating particle counting |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS57131036A JPS57131036A (en) | 1982-08-13 |
| JPH0226176B2 true JPH0226176B2 (en) | 1990-06-07 |
Family
ID=11920570
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP56016593A Granted JPS57131036A (en) | 1981-02-06 | 1981-02-06 | Light scattering type floating particle counting |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS57131036A (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS59202044A (en) * | 1983-05-02 | 1984-11-15 | Dan Sangyo Kk | Cloud chamber for observation of aerosol |
| JP3205413B2 (en) * | 1993-02-15 | 2001-09-04 | 株式会社日立製作所 | Particle measuring device and particle measuring method |
| JP4849626B2 (en) * | 2007-01-16 | 2012-01-11 | 東京エレクトロン株式会社 | Particle monitor system and substrate processing apparatus |
| WO2016156035A1 (en) * | 2015-03-27 | 2016-10-06 | Koninklijke Philips N.V. | Protecting an optical particle sensor from particulate deposits by thermophoresis |
| EP3444587A1 (en) * | 2017-08-14 | 2019-02-20 | Koninklijke Philips N.V. | Particle sensor and particle sensing method |
| EP3642587B1 (en) * | 2017-06-21 | 2020-12-30 | Koninklijke Philips N.V. | Particle sensor and particle sensing method |
| US10948391B2 (en) * | 2017-11-14 | 2021-03-16 | Aerodyne Microsystems Inc., a Delaware Corporation | Airborne particle detection system with orientation-dependent particle discrimination |
-
1981
- 1981-02-06 JP JP56016593A patent/JPS57131036A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS57131036A (en) | 1982-08-13 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US6639671B1 (en) | Wide-range particle counter | |
| JPS6311838A (en) | Granular size detector | |
| US5481357A (en) | Apparatus and method for high-efficiency, in-situ particle detection | |
| US20030052281A1 (en) | Apparatus to collect, classify, concentrate, and characterize gas-borne particles | |
| CN103018145A (en) | Novel real-time PM2.5 (particulate matter 2.5) mass concentration monitoring device and monitoring method | |
| JPH04500858A (en) | Multi-port parallel flow particle sensor | |
| Dahneke et al. | An aerosol beam spectrometer | |
| JPH0226176B2 (en) | ||
| Chen et al. | A study of density effect and droplet deformation in the TSI aerodynamic particle sizer | |
| US4825094A (en) | Real time particle fallout monitor with tubular structure | |
| US6082179A (en) | Particle measuring device having funnel-shaped collector for semiconductor clean room applications | |
| WO2023029733A1 (en) | Optical particle counter | |
| JPH01144850U (en) | ||
| JPS6335395Y2 (en) | ||
| JPS61288139A (en) | Fine particle detecting device | |
| JPS62293143A (en) | Measuring instrument for corpuscle | |
| JPH0498145A (en) | Counting device for particulates in fluid | |
| JP2879798B2 (en) | Particle detector for use in particle size detector | |
| KR20220034262A (en) | Curtain flow design for optical chambers | |
| EP0618440A1 (en) | Apparatus and method for high-efficiency, in-situ particle detection | |
| JPS6093944A (en) | Light-scattering particle measuring apparatus | |
| CN109855683A (en) | Integrated form indoor environment monitoring system and monitoring method | |
| JP4180952B2 (en) | Wide range particle counter | |
| JP3552389B2 (en) | Suspended dust measurement device | |
| JP2750082B2 (en) | Particle detecting apparatus and method |