JPH0621860B2 - Particle detector - Google Patents
Particle detectorInfo
- Publication number
- JPH0621860B2 JPH0621860B2 JP59070885A JP7088584A JPH0621860B2 JP H0621860 B2 JPH0621860 B2 JP H0621860B2 JP 59070885 A JP59070885 A JP 59070885A JP 7088584 A JP7088584 A JP 7088584A JP H0621860 B2 JPH0621860 B2 JP H0621860B2
- Authority
- JP
- Japan
- Prior art keywords
- laser
- resonator
- light
- aerosol
- mirror
- 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 - Lifetime
Links
- 239000002245 particle Substances 0.000 title claims description 8
- 238000001514 detection method Methods 0.000 claims description 23
- 230000003287 optical effect Effects 0.000 claims description 19
- 239000000443 aerosol Substances 0.000 claims description 14
- 239000010419 fine particle Substances 0.000 description 6
- 230000010355 oscillation Effects 0.000 description 4
- 238000000149 argon plasma sintering Methods 0.000 description 2
- 238000011109 contamination Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- 230000001678 irradiating effect Effects 0.000 description 1
- 238000002310 reflectometry Methods 0.000 description 1
- 230000035945 sensitivity Effects 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, e.g. by light scattering, diffraction, holography or imaging
-
- 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
- G01N15/10—Investigating individual particles
- G01N15/14—Electro-optical investigation, e.g. flow cytometers
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
- G01N21/25—Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
- G01N21/31—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
- G01N21/39—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using tunable lasers
- G01N2021/391—Intracavity sample
Description
【発明の詳細な説明】 〔発明の利用分野〕 本発明は、気体中に浮遊する微粒子を、微粒子からの散
乱光を試測することにより、検出する光散乱式微粒子検
出装置に関するものである。Description: FIELD OF THE INVENTION The present invention relates to a light-scattering type fine particle detection device for detecting fine particles floating in a gas by trial measuring scattered light from the fine particles.
従来から、被測定エアロゾルにレーザ光を照射して、そ
れからの散乱光を検出し、中に含まれる微粒子を計測す
る技術は公知である。この場合、検出性能を高めるため
には、照射光の強度を高めることが有効である。それに
は、レーザ出力を高めるための高出力レーザ装置を使用
するか、あるいは、レーザ共振器内に被測定エアロゾル
を通過させるなどの方法がとられていた。前者は装置の
大型化，入力電力の増大などを招き、後者では、レーザ
共振器のレーザビーム径はレーザ発振条件で決まり、検
出セル位置でのビーム径は必ずしも散乱光計測には最適
化されていない。また、検出セル配置の自由度が制約さ
れる。BACKGROUND ART Conventionally, there is known a technique of irradiating an aerosol to be measured with laser light, detecting scattered light from the aerosol, and measuring fine particles contained therein. In this case, it is effective to increase the intensity of irradiation light in order to improve the detection performance. For this purpose, a high-power laser device for increasing the laser output is used, or an aerosol to be measured is passed through the laser resonator. In the former case, the size of the device is increased and the input power is increased. In the latter case, the laser beam diameter of the laser resonator is determined by the laser oscillation conditions, and the beam diameter at the detection cell position is not necessarily optimized for scattered light measurement. Absent. Moreover, the degree of freedom in the arrangement of the detection cells is restricted.
本発明の目的は、上述した従来技術の問題を改善し、性
能の安定化，高度化をはかつた微粒子検出装置を提供す
ることにある。It is an object of the present invention to provide a particle detection device that improves the above-mentioned problems of the prior art, stabilizes performance, and enhances performance.
上記の目的を達成するため、本発明においては、その内
部に設けられたレーザ共振器によりレーザを共振させて
レーザ光を出力するレーザ発振器と、この発振器からの
レーザ光に共振する外部光共振器とを有し、この光共振
器内に検出セルを配置する。検出セルは、被測定エアロ
ゾルを吸引・排気する吸引ノズルおよび排気ノズルと、
被測定エアロゾルからの散乱光を集光する集光光学系
と、集光された散乱光を光電変換する受光素子とで構成
され、上記のレーザ発振器と外部光共振器とを含めた全
体で光散乱式の微粒子検出装置を構成する。この場合、
本発明では光共振器内の光路とエアロゾル通路とを交叉
させることを１つ特徴とする。In order to achieve the above object, in the present invention, a laser oscillator that resonates a laser by a laser resonator provided therein and outputs laser light, and an external optical resonator that resonates with the laser light from this oscillator And a detection cell is arranged in this optical resonator. The detection cell has a suction nozzle and an exhaust nozzle that suck and exhaust the measured aerosol.
It consists of a condensing optical system that condenses the scattered light from the aerosol to be measured, and a light receiving element that photoelectrically converts the condensed scattered light, and the total light including the above laser oscillator and external optical resonator A scattering type particle detector is constructed. in this case,
One feature of the present invention is that the optical path in the optical resonator and the aerosol passage are crossed.
このような構成をとることにより、外部光共振器の光強
度は、レーザ共振器内の強度とほぼ同等となり、しかも
エアロゾルに交叉するレーザビーム径を任意に変えるこ
とが可能であり、検出系全体の最適化がはかれる。さら
に、レーザ発振器の外部に共振器を設けて検出部分をレ
ーザ発振器とは完全に独立させることができるのでレー
ザ発振器が完全密閉できる。その結果、レーザ内部共振
器のレーザ発振用ミラーの汚れ、レーザ媒質端面の汚れ
を考慮する必要がなく、レーザ出力は常に安定である。
外部共振器は、フアブリーペロー型とし、２枚のミラー
を対向させて構成され、一方のミラーはレーザ光に対し
てほぼ完全な高反射性を有し、他方のミラーは、レーザ
光が一部内部に透過するよう部分透過性を有する高反射
性ミラーより構成されている。また、部分透過性ミラー
の代りにレーザ光出力側ミラーを使用し、これに対向さ
せて高反射ミラーを配置することも可能である。このよ
うな構成では、レーザの発振条件とは独立させて、外部
共振器の構成が可能となり、外部共振器内ミラーの曲率
を散乱光強度を増すよう適した値に選択したり、或は、
レーザビーム径収束用レンズを共振器内に配置すること
も可能である。したがつて、共振器内の光強度分布を変
えることが可能となり、より効率の高い測定が可能とな
る。With this configuration, the optical intensity of the external optical resonator is almost the same as the internal optical intensity of the laser resonator, and the diameter of the laser beam that intersects with the aerosol can be changed arbitrarily. Is optimized. Further, since the resonator can be provided outside the laser oscillator and the detecting portion can be made completely independent of the laser oscillator, the laser oscillator can be completely sealed. As a result, it is not necessary to consider the contamination of the laser oscillation mirror of the internal laser cavity and the contamination of the end surface of the laser medium, and the laser output is always stable.
The external resonator is of the Fabry-Perot type, and is composed of two mirrors facing each other. One mirror has almost complete high reflectivity for the laser light, and the other mirror has a part of the laser light inside. It is composed of a high-reflecting mirror having a partial transmissivity so as to be transmitted to the inside. It is also possible to use a laser light output side mirror instead of the partially transmissive mirror and dispose the high reflection mirror so as to face it. In such a configuration, the external resonator can be configured independently of the laser oscillation conditions, and the curvature of the external resonator internal mirror can be selected to a value suitable for increasing the scattered light intensity, or
It is also possible to dispose the laser beam diameter converging lens in the resonator. Therefore, it is possible to change the light intensity distribution in the resonator, and it is possible to perform measurement with higher efficiency.
第１図は、本発明の一実施例を示す光散乱式微粒子検出
装置の断面略図であり、(ａ)を側面図、(ｂ)は平面図で
ある。レーザ発振器１からのレーザ出力光６は、ミラー
２，２′を対向させて構成したフアブリペロー光共振器
内に入射させる。共振器内に入つたレーザ光８は、ミラ
ー２，２′間をくり返し反射する。このときの光強度
は、ミラーの光損失を無視すれば、レーザ光に共振した
状態では、レーザ発振器１の内部に設けられたレーザ共
振器内の光強度にほぼ等しい値が得られる。一方、この
共振器内に検出セル３を配置し、吸引ノズル４より被測
定エアロゾル７をレーザ光束８と交叉するように通過さ
せ、ついで排気ノズル５で検出セル外に排出させる。こ
のとき、エアロゾル中に微粒子が含まれるとレーザ光を
散乱させる。この散乱光は集光レンズ光学系９により集
光され光検出器１０により、電気信号に変換される。ス
リツト１１は、不要な迷光を除去するものでＳ／Ｎ比を
向上させるためのものである。FIG. 1 is a schematic cross-sectional view of a light-scattering type particle detection device showing an embodiment of the present invention, (a) is a side view and (b) is a plan view. The laser output light 6 from the laser oscillator 1 is made incident on the Fabry-Perot optical resonator formed by facing the mirrors 2 and 2 '. The laser beam 8 entering the resonator is repeatedly reflected between the mirrors 2 and 2 '. If the light loss at the mirror is neglected, the light intensity at this time is approximately equal to the light intensity in the laser resonator provided inside the laser oscillator 1 in a state of being resonated with the laser light. On the other hand, the detection cell 3 is arranged in this resonator, and the aerosol 7 to be measured is passed through the suction nozzle 4 so as to intersect with the laser light flux 8 and then discharged outside the detection cell by the exhaust nozzle 5. At this time, if the aerosol contains fine particles, the laser light is scattered. The scattered light is condensed by the condenser lens optical system 9 and converted into an electric signal by the photodetector 10. The slit 11 is for removing unnecessary stray light and is for improving the S / N ratio.
本発明の他の実施例を第２図に示す。この例では、レー
ザ発振器１′の出力側ミラー１２と別のミラー２′とで
光共振器を構成し、この中に検出セルを配置した場合で
あり、装置の簡素化が可能となる。なお、検出光学系は
省略してある。Another embodiment of the present invention is shown in FIG. In this example, the output side mirror 12 of the laser oscillator 1'and another mirror 2'constitute an optical resonator, and the detection cell is arranged in this, and the apparatus can be simplified. The detection optical system is omitted.
第３図は、本発明の別の実施例を示す図であり、レーザ
からの出力光６をレンズ１３により、エアロゾル７と最
適ビーム径１４で交叉するよう収束させる。このときの
光共振器はレーザ共振器用ミラー１２と別のミラー２と
で構成される。このような検出セル構造とすることによ
り、微粒子の検出精度を向上させることが可能となる。
尚、レンズとの組合せは第１図の例でも適用可能であ
る。FIG. 3 is a diagram showing another embodiment of the present invention, in which the output light 6 from the laser is converged by the lens 13 so as to intersect the aerosol 7 with the optimum beam diameter 14. The optical resonator at this time is composed of a laser resonator mirror 12 and another mirror 2. With such a detection cell structure, it is possible to improve the detection accuracy of fine particles.
The combination with the lens can also be applied to the example of FIG.
以上の如く、本発明によれば、レーザ共振器内に検出セ
ルを配置する方式と同等の検出感度を達成できると共
に、配置自由度がより高くなるうえ、レーザ発振器の発
振条件を変えないで、レーザビーム径をコントロールで
き、このため、レーザ出力も安定するので、実用的効果
の大なる微粒子検出装置の実現が可能となる。As described above, according to the present invention, it is possible to achieve the same detection sensitivity as the method of arranging the detection cell in the laser resonator, the degree of freedom of arrangement is further increased, and the oscillation condition of the laser oscillator is not changed. Since the diameter of the laser beam can be controlled, and the laser output can be stabilized, therefore, it is possible to realize a particle detection device having a great practical effect.
第１図は本発明の一実施例を示す断面図、第２図及び第
３図はそれぞれ本発明の他の実施例を示す断面略図であ
る。 １……レーザ共振器、２，２′……光共振器用ミラー、
３……検出セル、４……吸引ノズル、５……排気ノズ
ル、６……レーザ出力光、７……エアロゾルビーム、８
……光共振器内レーザビーム、９……集光レンズ、１０
……光検出器、１１……スリツト、１２……レーザ共振
器用ミラー、１３……レーザビーム収束用レンズ。FIG. 1 is a sectional view showing an embodiment of the present invention, and FIGS. 2 and 3 are schematic sectional views showing other embodiments of the present invention. 1 ... Laser resonator, 2, 2 '... Mirror for optical resonator,
3 ... Detection cell, 4 ... Suction nozzle, 5 ... Exhaust nozzle, 6 ... Laser output light, 7 ... Aerosol beam, 8
... laser beam in optical resonator, 9 ... condenser lens, 10
...... Photodetector, 11 ...... slit, 12 ...... Laser resonator mirror, 13 ...... Laser beam focusing lens.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 須田 匡 東京都国分寺市東恋ヶ窪１丁目280番地 株式会社日立製作所中央研究所内 (72)発明者 八掛 保夫 神奈川県足柄上郡中井町久所300番地 日 立電子エンジニアリング株式会社内 (72)発明者 塚田 一也 神奈川県足柄上郡中井町久所300番地 日 立電子エンジニアリング株式会社内 (56)参考文献 特開 昭59−42432（ＪＰ，Ａ) 特開 昭58−165008（ＪＰ，Ａ) 特開 昭50−104980（ＪＰ，Ａ) 実開 昭59−138750（ＪＰ，Ｕ) ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Tadashi Suda 1-280, Higashi Koigakubo, Kokubunji, Tokyo Inside Central Research Laboratory, Hitachi, Ltd. (72) Inventor Yasuo Yakake 300 Hisakata, Nakai-cho, Ashigara-gun, Kanagawa Pref. Within Engineering Co., Ltd. (72) Inventor Kazuya Tsukada 300, Hisasho, Nakai-cho, Ashigaragami-gun, Kanagawa Within Ritsudenshi Engineering Co., Ltd. (56) Reference JP-A-59-42432 (JP, A) JP-A-58-165008 (JP, A) JP-A-50-104980 (JP, A) Actually developed 59-138750 (JP, U)
Claims (3)
レーザを共振させてレーザ光を出力するレーザ発振器
と、このレーザ発振器の外側に配置されこのレーザ発振
器の出力を受けるミラーを有しかつ前記レーザ光に共振
する外部光共振器と、内部に被測定エアロゾルを含む検
出セルと、前記被測定エアロゾルからの散乱光を電気信
号に変換する光検出素子とからなり、前記検出セルを前
記外部光共振器内に配置したことを特徴とする微粒子検
出装置。1. A laser oscillator for resonating a laser by a laser resonator provided therein to output a laser beam, and a mirror arranged outside the laser oscillator for receiving an output of the laser oscillator. An external optical resonator that resonates with a laser beam, a detection cell that internally contains an aerosol to be measured, and a photodetector that converts scattered light from the aerosol to be measured into an electrical signal, and the detection cell is the external light. A particle detection device characterized by being arranged in a resonator.
一方が前記レーザ共振器の出力側のミラーである特許請
求の範囲第１項記載の微粒子検出装置。2. The particle detection device according to claim 1, wherein one of the mirrors for resonance of the external optical resonator is a mirror on the output side of the laser resonator.
前記外部光共振器内のレーザビームを集束させる集束手
段を設けたことを特徴とする特許請求の範囲第１項記載
の微粒子検出装置。3. The particle detection device according to claim 1, further comprising focusing means for focusing the laser beam in the external optical resonator at a laser irradiation portion of the aerosol to be measured.
Priority Applications (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59070885A JPH0621860B2 (en) | 1984-04-11 | 1984-04-11 | Particle detector |
| US06/721,904 US4685802A (en) | 1984-04-11 | 1985-04-10 | Small particle detection system |
| DE19853513035 DE3513035A1 (en) | 1984-04-11 | 1985-04-11 | SYSTEM FOR DETECTING SMALL PARTICLES |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59070885A JPH0621860B2 (en) | 1984-04-11 | 1984-04-11 | Particle detector |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS60214238A JPS60214238A (en) | 1985-10-26 |
| JPH0621860B2 true JPH0621860B2 (en) | 1994-03-23 |
Family
ID=13444429
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP59070885A Expired - Lifetime JPH0621860B2 (en) | 1984-04-11 | 1984-04-11 | Particle detector |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0621860B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9671325B2 (en) | 2015-07-02 | 2017-06-06 | Fuji Electric Co., Ltd. | Particle measuring device |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH071227B2 (en) * | 1986-03-07 | 1995-01-11 | 日立電子エンジニアリング株式会社 | Particle detector |
| JPS63133041A (en) * | 1986-11-25 | 1988-06-04 | Rion Co Ltd | Light scattering type fine particle meter |
| JPH02118244U (en) * | 1989-03-08 | 1990-09-21 | ||
| TWI408355B (en) * | 2009-09-28 | 2013-09-11 | Chane Yu Lai | Immediate detection device and detection method of biogas glue |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58165008A (en) * | 1982-03-25 | 1983-09-30 | Chiesuto Kk | Measurement of particle diameter distribution of micro particle |
| JPS5942432A (en) * | 1982-09-01 | 1984-03-09 | Rion Co Ltd | Light scattering type floating particle counting apparatus |
-
1984
- 1984-04-11 JP JP59070885A patent/JPH0621860B2/en not_active Expired - Lifetime
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9671325B2 (en) | 2015-07-02 | 2017-06-06 | Fuji Electric Co., Ltd. | Particle measuring device |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS60214238A (en) | 1985-10-26 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EXPY | Cancellation because of completion of term |