JPH05215685A - Infrared gas analyzer - Google Patents
Infrared gas analyzerInfo
- Publication number
- JPH05215685A JPH05215685A JP2033992A JP2033992A JPH05215685A JP H05215685 A JPH05215685 A JP H05215685A JP 2033992 A JP2033992 A JP 2033992A JP 2033992 A JP2033992 A JP 2033992A JP H05215685 A JPH05215685 A JP H05215685A
- Authority
- JP
- Japan
- Prior art keywords
- light
- infrared
- sensor
- gas analyzer
- band
- 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.)
- Pending
Links
Landscapes
- Investigating Or Analysing Materials By Optical Means (AREA)
Abstract
Description
【0001】[0001]
【産業上の利用分野】本発明は、試料ガス中に含まれて
いる各種成分ガスの定性, 定量分析を行う吸光式赤外線
ガス分析計の構成に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of an absorption type infrared gas analyzer for qualitatively and quantitatively analyzing various component gases contained in a sample gas.
【0002】[0002]
【従来の技術】頭記した吸光式の赤外線ガス分析計は、
試料ガス中に含まれる測定成分ガスによる赤外線の吸収
量から試料ガスの定性,定量分析を行うものであり、こ
の方式は一般に選択性が良く、測定感度が高いことから
ガス分析計として各種分野で広く使用されている。2. Description of the Related Art The absorption type infrared gas analyzer mentioned above is
Qualitative and quantitative analysis of the sample gas is performed from the amount of infrared absorption by the measurement component gas contained in the sample gas. This method generally has good selectivity and high measurement sensitivity, so it is used in various fields as a gas analyzer. Widely used.
【0003】次に、従来より実施されているシングルビ
ーム方式の吸光式赤外線ガス分析計の構成,並びにその
動作原理を図2により説明する。図において、1は試料
ガスを流す測定セル、2は測定セル1の入射側に備えた
赤外線光源、3は赤外線光源2から出射した光束を断続
させる回転式チョッパ、4は測定セル1の出射側に配備
した検出部であり、該検出部4はセンサ取付ブロック5
に試料ガス中に含まれる各種測定成分ガスに対応する複
数の赤外線センサ6がバンドパスフィルタ(赤外線セン
サに波長選択性を持たせるための多層膜干渉フィルタ)
7と対にして組み込まれている。なお、赤外線センサ6
は、例えば焦電型センサ,半導体センサなどの固体セン
サである。Next, the structure of a conventional single-beam absorption type infrared gas analyzer and its operating principle will be described with reference to FIG. In the figure, 1 is a measuring cell through which a sample gas flows, 2 is an infrared light source provided on the incident side of the measuring cell 1, 3 is a rotary chopper that intermittently interrupts the luminous flux emitted from the infrared light source 2, and 4 is the emitting side of the measuring cell 1. Is a detector installed on the sensor mounting block 5
A plurality of infrared sensors 6 corresponding to various measurement component gases contained in the sample gas are bandpass filters (multilayer film interference filters for giving infrared sensors wavelength selectivity).
It is installed as a pair with 7. The infrared sensor 6
Is a solid-state sensor such as a pyroelectric sensor or a semiconductor sensor.
【0004】かかる構成で、光源2から出射した赤外線
はチョッパ3により一定周期で断続した光束8となって
測定セル1に入射し、測定セル内を透過する過程で試料
ガス中に含まれている各種測定成分ガスにより固有の赤
外線波長が成分濃度に応じて吸収される。また、測定セ
ル1を透過した光束の一部はセンサ取付ブロック5の開
口窓よりバンドパスフィルタ7を通じて各赤外線センサ
6に受光され、その光量に応じた検出信号が電気信号に
変換して外部に取り出される。With this structure, the infrared light emitted from the light source 2 is contained in the sample gas in the process of entering the measurement cell 1 as a light beam 8 which is intermittently cut by the chopper 3 at a constant period and is transmitted through the measurement cell 1. Infrared wavelengths peculiar to various measurement component gases are absorbed according to the concentration of the components. Further, a part of the light flux transmitted through the measurement cell 1 is received by each infrared sensor 6 through the bandpass filter 7 through the opening window of the sensor mounting block 5, and the detection signal corresponding to the amount of the light is converted into an electric signal to the outside. Taken out.
【0005】[0005]
【発明が解決しようとする課題】ところで、前記のよう
に測定セル1の出射側端面に検出部4を直接向かい合わ
せに配備した構成では次記のような問題点が残る。すな
わち、測定セル1を透過した光束8のうち、符号8a,
8bで表す一部の光束はバンドパスフィルタ6を通じて
赤外線センサ7に到達するが、それ以外の光束8cはセ
ンサ取付ブロック5(例えばアルミ製)を照射してブロ
ックを加熱する。このために、センサ取付ブロック5の
温度が上昇して赤外線センサ6に伝熱し、これがセンサ
検出信号に対するドリフト発生の原因となる。そこで、
従来ではセンサ取付ブロック5に赤外線センサとともに
温度補償素子を組み込み、周囲温度の変化によるセンサ
検出信号の温度補償を行うような手段を講じているが、
この方法でもセンサ取付ブロック5の温度分布のむらが
基で、赤外線センサと温度補償素子との間に異なる温度
変化が加わる場合にはドリフトの発生,S/N比の低下
を招くことになる。By the way, the following problems remain in the structure in which the detecting portion 4 is arranged directly opposite to the emission side end surface of the measuring cell 1 as described above. That is, among the luminous fluxes 8 that have passed through the measurement cell 1, reference numerals 8a,
A part of the light flux represented by 8b reaches the infrared sensor 7 through the bandpass filter 6, but the other light flux 8c irradiates the sensor mounting block 5 (for example, made of aluminum) to heat the block. For this reason, the temperature of the sensor mounting block 5 rises and heat is transferred to the infrared sensor 6, which causes a drift with respect to the sensor detection signal. Therefore,
Conventionally, a temperature compensating element is incorporated in the sensor mounting block 5 together with the infrared sensor, and means for compensating the temperature of the sensor detection signal due to a change in ambient temperature is taken.
Even with this method, if a different temperature change is applied between the infrared sensor and the temperature compensating element due to the uneven temperature distribution of the sensor mounting block 5, a drift may occur and the S / N ratio may be lowered.
【0006】また、別な問題として、赤外線センサ6に
組合わせたバンドパスフィルタ(多層膜干渉フィルタ)
7は、基本的に光軸と平行に光線が入射した条件で所定
の波長選択特性を発揮するように設計されているため、
図示に表した光束8bのように測定セル1内を透過する
過程で壁面に全反射して斜め方向から光がバンドパスフ
ィルタ7に入射した場合にはサイドバンドが現れ、赤外
線センサに対する波長選択性に悪影響を及ぼすといった
不具合が生じる。As another problem, a bandpass filter (multilayer interference filter) combined with the infrared sensor 6 is provided.
7 is basically designed to exhibit a predetermined wavelength selection characteristic under the condition that a light ray is incident parallel to the optical axis,
When the light beam 8b shown in the figure passes through the measurement cell 1 and is totally reflected on the wall surface and light is incident on the bandpass filter 7 from an oblique direction, sidebands appear and the wavelength selectivity to the infrared sensor is increased. There is a problem that it adversely affects the.
【0007】本発明は上記の点にかんがみなされたもの
であり、その目的は前記した課題を解決して検出部のセ
ンサ取付ブロックに対する熱的影響の防止,並びにバン
ドパスフィルタに対する光の斜め入射を抑えて成分ガス
の分析精度の向上化が図れるようにした赤外線ガス分析
計を提供することにある。The present invention has been made in view of the above points, and an object of the present invention is to solve the above-mentioned problems by preventing thermal influence on a sensor mounting block of a detection unit and oblique incidence of light on a bandpass filter. An object of the present invention is to provide an infrared gas analyzer capable of suppressing the component gas to improve the accuracy of analysis.
【0008】[0008]
【課題を解決するための手段】上記目的を達成するため
に、本発明の赤外線ガス分析計においては、測定セルの
出射側端面と検出部との間に、赤外線センサに通じる透
光穴を開口してセンサ取付ブロックの前面を覆う断熱性
の遮光スペーサを介装配備して構成するものとする。In order to achieve the above object, in the infrared gas analyzer of the present invention, a light transmitting hole communicating with the infrared sensor is opened between the emitting side end face of the measuring cell and the detecting portion. Then, a heat-insulating light-shielding spacer that covers the front surface of the sensor mounting block is provided and configured.
【0009】また、前記構成における遮光スペーサにつ
いては、スペーサに開口した透光穴の内周壁面を光反射
率の低い光吸収面として構成するのが好ましい。Further, in the light-shielding spacer having the above structure, it is preferable that the inner peripheral wall surface of the light-transmitting hole opened in the spacer is formed as a light-absorbing surface having a low light reflectance.
【0010】[0010]
【作用】上記の構成により、測定セルを透過した光束
は、遮光スペーサの透光穴を除いて遮光スペーサにより
遮光されので、センサ取付ブロックが直接赤外線の照射
を受けて加熱されることがない。しかも、遮光スペーサ
自身は例えばゴムなどの断熱材で作られたものであって
センサ取付ブロック側への伝熱も殆どなく、赤外線セン
サの検出信号に対する熱的なドリフトの影響が軽減され
る。With the above construction, the light flux transmitted through the measuring cell is shielded by the light-shielding spacer except the light-transmitting hole of the light-shielding spacer, so that the sensor mounting block is not directly irradiated with infrared rays and heated. In addition, the light-shielding spacer itself is made of a heat insulating material such as rubber and has almost no heat transfer to the sensor mounting block side, and the influence of thermal drift on the detection signal of the infrared sensor is reduced.
【0011】また、遮光スペーサの厚さ寸法をあらかじ
め大きく選定しておくことにより、前方斜め方向からス
ペーサの透光穴に入光した光は大半がバンドパスフィル
タへ到達する以前に透光穴の内周壁面に当たる。ここ
で、透光穴の内周壁面を光反射率の低い光吸収面として
おくことにより、斜め方向から遮光スペーサの透光穴に
入光したたった光は壁面に吸収カットされる。したがっ
て、後段のバンドパスフィルタに対し斜め方向からの入
射光の割合は極小となり、斜め入射光に起因して生じる
サイドバンドなど、赤外線センサに対する波長選択性の
悪影響が殆ど現れなくなる。Further, by largely selecting the thickness of the light-shielding spacer in advance, most of the light entering the light-transmitting hole of the spacer from the front oblique direction is mostly transmitted through the light-transmitting hole before reaching the bandpass filter. Hit the inner wall. Here, by setting the inner peripheral wall surface of the light transmitting hole as a light absorbing surface having a low light reflectance, only the light entering the light transmitting hole of the light shielding spacer from an oblique direction is absorbed and cut by the wall surface. Therefore, the ratio of the incident light from the oblique direction to the bandpass filter in the latter stage is minimized, and the adverse effect of the wavelength selectivity on the infrared sensor such as the side band caused by the oblique incident light hardly appears.
【0012】[0012]
【実施例】図1は本発明の実施例を示すものであり、図
2に対応する同一部材には同じ符号が付してある。図示
実施例においては、測定セル1の出射側端面と検出部4
との間に例えばゴムなどのように光反射率の低い断熱材
で作られた遮光スペーサ9が新た介装配備されている。
そして、遮光スペーサ9には検出部4のセンサ取付ブロ
ック5に組み込まれた赤外線センサ6に対応する位置に
透光穴9aが開口している。なお、遮光スペーサの材料
自身が光を良く反射するものである場合には、少なくと
も透光穴9aの内周壁面を粗面化する,あるいは光吸収
性のよい材料をコーティングするなどして光反射率を低
めるようにするのがよい。DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of the present invention, in which the same members corresponding to those in FIG. 2 are designated by the same reference numerals. In the illustrated embodiment, the emitting end face of the measuring cell 1 and the detector 4
A light-shielding spacer 9 made of a heat insulating material having a low light reflectance, such as rubber, is newly interposed between and.
The light-shielding spacer 9 has a light-transmitting hole 9a at a position corresponding to the infrared sensor 6 incorporated in the sensor mounting block 5 of the detection unit 4. When the material of the light-shielding spacer itself reflects light well, at least the inner peripheral wall surface of the light-transmitting hole 9a is roughened or light-absorbing material is coated to reflect the light. It is better to lower the rate.
【0013】かかる構成により、赤外線光源(図2参
照)より出射して測定セル1を透過した光束8のうち、
遮光スペーサ9の透光穴9aに入光する光束8a,8b
を除く光束8cは遮光スペーサ9に遮光され、後部のセ
ンサ取付ブロック5に直接照射されることがない。しか
も遮光スペーサ自身は断熱性を有するので検出部4への
伝熱も殆どなく、センサ取付ブロック5に対する不当な
加熱,温度むらが防止される。With this configuration, of the light flux 8 emitted from the infrared light source (see FIG. 2) and transmitted through the measurement cell 1,
Light fluxes 8a and 8b entering the light transmitting hole 9a of the light shielding spacer 9
The light beam 8c except for is shielded by the light shielding spacer 9 and is not directly irradiated to the sensor mounting block 5 at the rear portion. In addition, since the light-shielding spacer itself has a heat insulating property, there is almost no heat transfer to the detecting portion 4, so that improper heating and uneven temperature of the sensor mounting block 5 can be prevented.
【0014】また、遮光スペーサ9の透光穴9aに入光
する前記光束8a,8bのうち、光軸と平行な光束8a
はそのまま透光穴9aを透過してバンドパスフィルタ7
に入射するのに対し、斜め方向から入射する光束8bは
透光穴9aを通過する過程で殆どが透光穴の内周壁面に
当たって吸収カットされる。したがって、後段のバンド
パスフィルタ7へ斜め方向から入射する光の割合は極め
て小さくなり、サイドバンドに起因する測定分析結果へ
の影響が大幅に低減されることになる。Of the light beams 8a and 8b entering the light transmitting hole 9a of the light-shielding spacer 9, a light beam 8a parallel to the optical axis.
Is transmitted through the transparent hole 9a as it is, and the bandpass filter 7
On the other hand, most of the light beam 8b incident from the oblique direction hits the inner peripheral wall surface of the light transmitting hole and is absorbed and cut in the process of passing through the light transmitting hole 9a. Therefore, the proportion of light obliquely incident on the bandpass filter 7 in the subsequent stage is extremely small, and the influence on the measurement and analysis result due to the sideband is significantly reduced.
【0015】[0015]
【発明の効果】以上述べたように本発明の構成によれ
ば、測定セルの出射側端面と検出部との間に介装した断
熱性遮光スペーサの機能により、検出部のセンサ取付ブ
ロックが測定セルを透過した光束の直接照射を受けて不
当に加熱,昇温するのが良好に防止される。これによ
り、センサ取付ブロックに組み込まれた赤外線センサ周
辺の不当な加熱,温度変動が小さくなるので、検出部に
おいて安定した温度補償を行うことができる。さらに、
遮光スペーサの介在により、バンドパスフィルタに対す
る斜め方向からの入射光の割合を低めてサイサドバンド
の発生を抑制できるなど、赤外線ガス分析計の測定分析
精度の大幅な向上化が図れる。As described above, according to the structure of the present invention, the sensor mounting block of the detecting portion is measured by the function of the heat insulating light-shielding spacer interposed between the emitting end face of the measuring cell and the detecting portion. It is possible to effectively prevent undesired heating and temperature rise due to direct irradiation of the light flux transmitted through the cell. As a result, undue heating and temperature fluctuations around the infrared sensor incorporated in the sensor mounting block are reduced, so that stable temperature compensation can be performed in the detection unit. further,
By interposing the light-shielding spacer, it is possible to significantly reduce the measurement and analysis accuracy of the infrared gas analyzer, such as reducing the ratio of incident light from the diagonal direction with respect to the bandpass filter and suppressing the generation of a cissade band.
【図1】本発明実施例の要部構成断面図FIG. 1 is a cross-sectional view of the main configuration of an embodiment of the present invention.
【図2】従来におけるシングルビーム式赤外線ガス分析
計の全体構成図FIG. 2 is an overall configuration diagram of a conventional single-beam infrared gas analyzer
1 測定セル 2 赤外線光源 4 検出部 5 センサ取付ブロック 6 赤外線センサ 7 バンドパスフィルタ 8 光束 9 遮光スペーサ 9a 透光穴 1 Measuring Cell 2 Infrared Light Source 4 Detecting Section 5 Sensor Mounting Block 6 Infrared Sensor 7 Band Pass Filter 8 Luminous Flux 9 Light Shielding Spacer 9a Transparent Hole
Claims (2)
入射側に赤外線光源を、出射側には赤外線センサをバン
ドパスフィルタとともにセンサ取付ブロックに組み込ん
でなる検出部を配備した吸光式の赤外線ガス分析計にお
いて、測定セルの出射側端面と検出部との間に、赤外線
センサに通じる透光穴を開口してセンサ取付ブロックの
前面を覆う断熱性の遮光スペーサを介装配備したことを
特徴とする赤外線ガス分析計。1. An infrared ray of absorption type in which an infrared light source is provided on the incident side of a measuring cell filled with a sample gas and an infrared sensor is provided on the emitting side together with a bandpass filter in a sensor mounting block. In the gas analyzer, a heat-insulating light-shielding spacer that covers the front surface of the sensor mounting block by opening a light-transmitting hole that communicates with the infrared sensor is provided between the emission end surface of the measurement cell and the detection unit. Infrared gas analyzer.
て、遮光スペーサに開口した透光穴の内周壁面を光反射
率の低い光吸収面としたことを特徴とする赤外線ガス分
析計。2. The infrared gas analyzer according to claim 1, wherein an inner peripheral wall surface of the light transmitting hole opened in the light shielding spacer is a light absorbing surface having a low light reflectance.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2033992A JPH05215685A (en) | 1992-02-06 | 1992-02-06 | Infrared gas analyzer |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2033992A JPH05215685A (en) | 1992-02-06 | 1992-02-06 | Infrared gas analyzer |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH05215685A true JPH05215685A (en) | 1993-08-24 |
Family
ID=12024384
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP2033992A Pending JPH05215685A (en) | 1992-02-06 | 1992-02-06 | Infrared gas analyzer |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH05215685A (en) |
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2389177A (en) * | 2002-05-31 | 2003-12-03 | Marconi Applied Techn Ltd | An optical gas sensor whose sensor has a predetermined range of angle of reception |
JP2007225386A (en) * | 2006-02-22 | 2007-09-06 | Horiba Ltd | Gas analyzer and semiconductor manufacturing apparatus |
US7488942B2 (en) | 2002-11-07 | 2009-02-10 | E2V Technologies (Uk) Limited | Gas sensors |
JP2009047612A (en) * | 2007-08-21 | 2009-03-05 | Toyota Motor Corp | Exhaust gas analysis sensor |
JP2014509383A (en) * | 2010-12-20 | 2014-04-17 | バインダー ゲーエムベーハー | Measuring system for measuring CO2 concentration in a weathering tester or incubator |
EP2772749A4 (en) * | 2011-10-24 | 2015-03-18 | Panasonic Ip Man Co Ltd | Detector |
CN112129743A (en) * | 2020-10-20 | 2020-12-25 | 西安交通大学 | System and method for measuring mercury content in flue gas on line based on LIBS technology |
-
1992
- 1992-02-06 JP JP2033992A patent/JPH05215685A/en active Pending
Cited By (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2389177A (en) * | 2002-05-31 | 2003-12-03 | Marconi Applied Techn Ltd | An optical gas sensor whose sensor has a predetermined range of angle of reception |
GB2389177B (en) * | 2002-05-31 | 2006-03-15 | Marconi Applied Techn Ltd | Gas sensors |
US7488942B2 (en) | 2002-11-07 | 2009-02-10 | E2V Technologies (Uk) Limited | Gas sensors |
JP2007225386A (en) * | 2006-02-22 | 2007-09-06 | Horiba Ltd | Gas analyzer and semiconductor manufacturing apparatus |
JP4727444B2 (en) * | 2006-02-22 | 2011-07-20 | 株式会社堀場製作所 | Gas analyzer and semiconductor manufacturing apparatus |
JP2009047612A (en) * | 2007-08-21 | 2009-03-05 | Toyota Motor Corp | Exhaust gas analysis sensor |
JP2014509383A (en) * | 2010-12-20 | 2014-04-17 | バインダー ゲーエムベーハー | Measuring system for measuring CO2 concentration in a weathering tester or incubator |
EP2772749A4 (en) * | 2011-10-24 | 2015-03-18 | Panasonic Ip Man Co Ltd | Detector |
US9239291B2 (en) | 2011-10-24 | 2016-01-19 | Panasonic Intellectual Property Management Co., Ltd. | Detector |
CN112129743A (en) * | 2020-10-20 | 2020-12-25 | 西安交通大学 | System and method for measuring mercury content in flue gas on line based on LIBS technology |
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