JP2764109B2 - Gas identification sensor system - Google Patents
Gas identification sensor systemInfo
- Publication number
- JP2764109B2 JP2764109B2 JP5056389A JP5056389A JP2764109B2 JP 2764109 B2 JP2764109 B2 JP 2764109B2 JP 5056389 A JP5056389 A JP 5056389A JP 5056389 A JP5056389 A JP 5056389A JP 2764109 B2 JP2764109 B2 JP 2764109B2
- Authority
- JP
- Japan
- Prior art keywords
- gas
- sensor system
- resonance frequency
- change
- impedance
- 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
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Description
【発明の詳細な説明】 〔産業上の利用分野〕 この発明は、化学工業、環境計測分野におけるガスの
計測、識別を行う装置に関する。Description: TECHNICAL FIELD The present invention relates to an apparatus for measuring and identifying gas in the chemical industry and the environmental measurement field.
この発明の水晶振動子のインピーダンス変化と共振周
波数変化の比を指標とするガス識別センサーシステム
は、感応膜を有する水晶振動子、電気的インピーダンス
および共振周波数測定装置、記録装置（または表示装
置）から構成され、ガスの濃度の測定と識別を行う装置
である。このうち、インピーダンスおよび共振周波数測
定装置は、周波数走引型インピーダンスアナライザーと
コンピューター、または、発振回路と周波数カウンター
と高周波電流計から構成した。A gas identification sensor system using the ratio of the change in impedance and the change in resonance frequency of a quartz oscillator according to the present invention as an index is provided by a quartz oscillator having a sensitive film, an electrical impedance and resonance frequency measuring device, and a recording device (or display device). It is a device configured to measure and identify gas concentration. Among them, the impedance and resonance frequency measuring device was composed of a frequency sweep type impedance analyzer and a computer, or an oscillation circuit, a frequency counter and a high frequency ammeter.
さらに、識別能を高めるため水晶振動子の電気的イン
ピーダンス変化と共振周波数変化の比、および、２つの
水晶振動子の共振周波数変化の比を指標とし、ガスの識
別を行なうガス識別センサーシステムは、少なくとも、
感応膜を有する複数の水晶振動子と同数のリレー、イン
ピーダンスおよび共振周波数測定装置、記録装置（また
は表示装置）より構成される。Furthermore, in order to enhance the discriminating ability, a gas discrimination sensor system that performs gas discrimination using a ratio between a change in the electrical impedance of the crystal unit and a change in the resonance frequency and a ratio between the change in the resonance frequency of the two crystal units as an index is at least,
It is composed of the same number of relays as a plurality of quartz oscillators having a sensitive film, impedance and resonance frequency measuring devices, and a recording device (or display device).
この装置によって、これまでの水晶振動子センサーシ
ステムに比べて、より少ないセンサー素子でガスの識別
が行えるようになった。With this device, gas identification can be performed with fewer sensor elements as compared with the conventional quartz oscillator sensor system.
従来、圧電素子とくに水晶振動子を利用したガスセン
サーでは、ガスの識別のために複数の有機薄膜で被覆し
た水晶振動子を用い、発振回路によって、発振周波数を
測定する方法がとられていた。Conventionally, in a gas sensor using a piezoelectric element, particularly a quartz oscillator, a method of measuring an oscillation frequency by an oscillation circuit using a quartz oscillator covered with a plurality of organic thin films for gas identification has been adopted.
従来の発振周波数を指標とする測定法でガスの識別を
行なう場合、１つのセンサーについて、共振周波数変化
という１つの指標しか得られないため、識別を行なうた
めに数多くのセンサーを使用する必要があった。When a gas is identified by a conventional measurement method using an oscillation frequency as an index, only one index, that is, a change in resonance frequency, can be obtained for one sensor. Therefore, it is necessary to use a large number of sensors for identification. Was.
上記の課題を解決するために、新たに水晶振動子のイ
ンピーダンス変化と共振周波数変化の２つの指標を利用
し、この比を求めることによって、ガスの識別を行なわ
せることにした。さらに、感応膜の異なる２つの水晶振
動子の共振周波数変化の比を合わせて使用することによ
って、識別の効果を高めた。In order to solve the above-mentioned problem, gas is newly identified by using two indices of a change in impedance and a change in resonance frequency of the crystal unit and calculating the ratio. Furthermore, the effect of discrimination was enhanced by using the ratio of the change in the resonance frequency of the two quartz resonators having different sensitive films.
これまで水晶振動子ガスセンサーの共振周波数変化
は、Saurebreyの式に従うとされていた。しかし、Saure
breyの式では、水晶振動子表面の弾性的な膜に限って適
用されるものであり、高分子膜のような粘弾性的な膜で
は、そのまま適用することはできない。従って、実際の
周波数変化は、Saurebreyの式から計算される値と異な
ると考えられる。一方、高分子膜の粘弾性的な性質か
ら、水晶振動子などの圧電素子表面における振動に対し
て、摩擦抵抗を与えることになる。圧電素子において、
この機械的な摩擦抵抗は、電気的な共振抵抗に反映され
ることが既に知られている［H.Muramatsu et al.,Ana
l.Chem.,60（1988）2142］。ここで、共振抵抗は、高分
子膜の密度と粘度に依存して変化すると考えられる。し
たがって、ガスが高分子膜に吸着した場合、まず、密度
の変化として共振抵抗が変化する。これに加えて、高分
子膜の粘弾性的性質（特に粘性的性質）が変化すること
によって、さらに共振抵抗の値が変化すると考えられ
る。ここで、吸着するガスの種類によって、膜の構造変
化への寄与が異なることから、吸着するガスによって、
共振周波数変化と共振抵抗の比は、異なる変化をするも
のであり、これを利用することによって、ガス識別が可
能となる。Until now, the change in the resonance frequency of a quartz oscillator gas sensor was said to follow Saurebrey's equation. But Saure
The Brey's equation is applied only to an elastic film on the surface of a quartz oscillator, and cannot be applied to a viscoelastic film such as a polymer film as it is. Therefore, the actual frequency change is considered to be different from the value calculated from the Saurebrey equation. On the other hand, due to the viscoelastic properties of the polymer film, frictional resistance is given to vibration on the surface of a piezoelectric element such as a quartz oscillator. In the piezoelectric element,
It is already known that this mechanical frictional resistance is reflected in the electrical resonance resistance [H. Muramatsu et al., Ana
l. Chem., 60 (1988) 2142]. Here, it is considered that the resonance resistance changes depending on the density and the viscosity of the polymer film. Therefore, when the gas is adsorbed on the polymer film, first, the resonance resistance changes as the density changes. In addition to this, it is considered that the value of the resonance resistance further changes when the viscoelastic property (particularly, the viscous property) of the polymer film changes. Here, since the contribution to the structural change of the film differs depending on the type of the gas to be adsorbed,
The ratio between the resonance frequency change and the resonance resistance changes differently, and by using this, the gas can be identified.
以下、この発明の実施例を図面に基づいて説明する。
第１図ａは、本発明のガスセンサーシステムの模式図を
示したものである。第１図ａにおいて、高分子膜４をコ
ートした圧電素子１は、圧電素子の電気的インピーダン
スおよび共振周波数測定装置２に接続され、装置２に
は、記録装置（または表示装置）３が接続されている。Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1a shows a schematic view of the gas sensor system of the present invention. In FIG. 1a, a piezoelectric element 1 coated with a polymer film 4 is connected to a device 2 for measuring the electrical impedance and resonance frequency of the piezoelectric element, and a recording device (or display device) 3 is connected to the device 2. ing.
第１図ｂは、２つの高分子膜被覆圧電素子として、ア
ゾレクチン膜５とアゾレクチン／コレステロール3:1の
混合膜６を被覆したATカット9MHzの水晶振動子７、7aと
リレー８、8aを用い、電気的インピーダンスおよび共振
周波数測定装置２として、インピーダンスアナライザー
とコンピューターを使用するセンサーシステムの模式図
である。第１図ｂにおいて、水晶振動子７、7aはフロー
セル９中に固定され、このフローセル９中へ匂い物質ガ
スが送り込まれるようになっている。FIG. 1B shows an AT-cut 9 MHz quartz oscillator 7, 7a and a relay 8, 8a coated with an azolectin film 5 and an azolectin / cholesterol 3: 1 mixed film 6 as two polymer film-coated piezoelectric elements. FIG. 1 is a schematic diagram of a sensor system using an impedance analyzer and a computer as an electrical impedance and resonance frequency measuring device 2. In FIG. 1b, the quartz oscillators 7 and 7a are fixed in a flow cell 9, and an odor substance gas is fed into the flow cell 9.
共振抵抗の測定は、アドミッタンスの虚数成分サセプ
タンスの最大値、最小値を与える周波数の間に共振周波
数変化があることから、まず、この範囲を周波数掃引し
てアドミッタンスの測定を行った。測定したコンダクタ
ンスとサセプタンスのデータをXY軸上にプロットした場
合描かれる円の直径を求め、この逆数を共振抵抗の値と
した。また、コンダクタンスの最大値を示す周波数を共
振周波数として求めた。この処理はすべてコンピュータ
ーで行うことが可能であり、１回の測定は、４秒以内で
行うことが可能であった。In the measurement of the resonance resistance, since there was a change in the resonance frequency between the frequencies giving the maximum value and the minimum value of the imaginary component susceptance of the admittance, first, the frequency was swept over this range to measure the admittance. The diameter of the circle drawn when the measured conductance and susceptance data were plotted on the XY axis was determined, and the reciprocal thereof was used as the value of the resonance resistance. Further, the frequency showing the maximum value of the conductance was determined as the resonance frequency. All of this processing could be performed by a computer, and one measurement could be performed within 4 seconds.
本発明の装置によって、共振抵抗と共振周波数変化の
比は、ガスの種類によって変化し、ガスの識別に利用可
能であることがわかる。第２図は、横軸に、２つのセン
サーの共振周波数変化の標準化した値（共振周波数変化
をそれぞれ膜形成時の周波数変化で割った値）の比（混
合膜で得た値をアゾレクチンで得た値で割った値）をと
ったもので、縦軸は、アゾレクチンに対する標準化した
共振周波数変化と標準化した共振抵抗の比（共振周波数
変化を共振抵抗変化で割った値）をとったものであり、
測定対象として、β−イオノン、シトラール、メント
ン、ｎ−アルミアセテート、エタノール、メタノール、
アセトン、エチルエーテルを使用したものである。第２
図に示されるように、２つの感応膜を有するセンサーに
よって、匂い物質の識別を行なうことが可能であること
が示された。According to the apparatus of the present invention, it can be seen that the ratio between the resonance resistance and the change in the resonance frequency changes depending on the type of gas and can be used for gas identification. FIG. 2 shows the ratio of the standardized value of the resonance frequency change of the two sensors (the value obtained by dividing the resonance frequency change by the frequency change at the time of film formation) of the two sensors (the value obtained with the mixed film was obtained with azolectin). The vertical axis shows the ratio of the normalized resonance frequency change to the azo lectin to the standardized resonance resistance (resonance frequency change divided by resonance resistance change). ,
As the measurement target, β-ionone, citral, mentone, n-aluminum acetate, ethanol, methanol,
Acetone and ethyl ether were used. Second
As shown in the figure, it was shown that the odorant can be identified by a sensor having two sensitive films.
一方、インピーダンスおよび共振周波数変化測定回路
として、発振回路と周波数カウンターと高周波電流計を
用い、発振周波数と共振抵抗に変わる指標として水晶振
動子に流れる電流の測定を行なうことによっても同様に
ガスの識別を行なうことができた。On the other hand, by using an oscillation circuit, a frequency counter, and a high-frequency ammeter as an impedance and resonance frequency change measurement circuit, and by measuring the current flowing through the crystal resonator as an index that changes to the oscillation frequency and the resonance resistance, the gas can be similarly identified. Was able to do.
さらに、インピーダンスアナライザーの代わりに、周
波数走引回路と周波数カウンターを使用し、マイクロコ
ンピューターを用いて、電流がピークを示す周波数を近
似的に共振周波数とし、ピークの高さから、近似的に共
振抵抗を算出することによっても、測定が可能だった。Furthermore, a frequency sweep circuit and a frequency counter are used in place of the impedance analyzer, and the frequency at which the current shows a peak is approximately determined as the resonance frequency using a microcomputer, and the resonance resistance is approximately determined from the height of the peak. The measurement was also possible by calculating.
また本装置で得られた共振抵抗または共振周波数の変
化量からガスの濃度を測定することも可能である。It is also possible to measure the gas concentration from the amount of change in the resonance resistance or the resonance frequency obtained by the present apparatus.
本発明のガス識別センサーシステムによって、従来よ
り少ない数のセンサーによって、ガスの識別を行なうこ
とが可能となった。The gas identification sensor system of the present invention makes it possible to identify a gas with a smaller number of sensors than before.
第１図ａは、本発明のガス識別センサーシステムの模式
図、第１図ｂは、本発明の実施例で使用したセンサーシ
ステムの模式図、第２図は、本発明のセンサーシステム
によるガス識別のための２次元パターンを示す図であ
る。FIG. 1a is a schematic diagram of a gas identification sensor system of the present invention, FIG. 1b is a schematic diagram of a sensor system used in an embodiment of the present invention, and FIG. 2 is a gas identification by the sensor system of the present invention. FIG. 3 is a diagram showing a two-dimensional pattern for the above.
───────────────────────────────────────────────────── フロントページの続き (58)調査した分野(Int.Cl.6，ＤＢ名) G01N 5/02,9/00,11/00 G01N 27/02 - 27/24 ＪＩＣＳＴファイル（ＪＯＩＳ)──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int.Cl. 6 , DB name) G01N 5 / 02,9 / 00,11 / 00 G01N 27/02-27/24 JICST file (JOIS)
Claims (8)
共振周波数変化の比を指標とし、ガスの識別を行なうガ
ス識別センサーシステム。1. A gas discrimination sensor system for discriminating a gas using a ratio between a change in electrical impedance and a change in resonance frequency of a crystal unit as an index.
インピーダンスおよび共振周波数測定装置、記録装置
（または表示装置）より構成される請求項１記載のガス
識別センサーシステム。2. The gas identification sensor system according to claim 1, comprising at least a quartz oscillator having a sensitive film, an impedance and resonance frequency measuring device, and a recording device (or a display device).
共振周波数変化の比、および、２つの水晶振動子の共振
周波数変化の比を指標とし、ガスの識別を行なうガス識
別センサーシステム。3. A gas discrimination sensor system for discriminating a gas using a ratio between a change in electrical impedance of a crystal unit and a change in resonance frequency and a ratio between a change in resonance frequency between two crystal units as an index.
動子と同数のリレー、インピーダンスおよび共振周波数
測定装置、記録装置（または表示装置）より構成される
請求項３記載のガス識別センサーシステム。4. The gas discrimination sensor system according to claim 3, comprising at least as many relays, impedance and resonance frequency measuring devices and recording devices (or display devices) as the plurality of quartz oscillators having a sensitive film.
装置が、周波数走引型インピーダンスアナライザーとコ
ンピューターより構成される請求項１あるいは３記載の
ガス識別センサーシステム。5. The gas identification sensor system according to claim 1, wherein said impedance and resonance frequency measuring device comprises a frequency sweep type impedance analyzer and a computer.
装置が、発振回路と周波数カウンターと高周波電流計に
より構成される請求項１あるいは３記載のガス識別セン
サーシステム。6. The gas discrimination sensor system according to claim 1, wherein said impedance and resonance frequency measuring device comprises an oscillation circuit, a frequency counter, and a high-frequency ammeter.
ある請求項１あるいは３記載のガス識別センサーシステ
ム。7. The gas identification sensor system according to claim 1, wherein said quartz oscillator is an AT-cut quartz oscillator.
成物質である請求項１あるいは３記載のガス識別センサ
ーシステム。8. The gas identification sensor system according to claim 1, wherein the sensitive membrane is a lipid or other cell membrane constituent.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5056389A JP2764109B2 (en) | 1989-03-02 | 1989-03-02 | Gas identification sensor system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5056389A JP2764109B2 (en) | 1989-03-02 | 1989-03-02 | Gas identification sensor system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH02228538A JPH02228538A (en) | 1990-09-11 |
| JP2764109B2 true JP2764109B2 (en) | 1998-06-11 |
Family
ID=12862471
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5056389A Expired - Lifetime JP2764109B2 (en) | 1989-03-02 | 1989-03-02 | Gas identification sensor system |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2764109B2 (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3057324B2 (en) * | 1990-09-13 | 2000-06-26 | セイコーインスツルメンツ株式会社 | Chemical substance identification sensor system |
| JPH05306983A (en) * | 1991-08-16 | 1993-11-19 | Kaoru Santo | Odorant sensor |
| ES2845173T3 (en) * | 2012-05-24 | 2021-07-26 | Air Prod & Chem | Procedure and apparatus for regulating the mass flow rate of a gas |
| JP6726376B1 (en) * | 2020-03-13 | 2020-07-22 | 東京瓦斯株式会社 | Gas leak detection system, gas leak detection device and program |
-
1989
- 1989-03-02 JP JP5056389A patent/JP2764109B2/en not_active Expired - Lifetime
Non-Patent Citations (2)
| Title |
|---|
| 計測技術 １７［８］ （１９８９−７−５） Ｐ．３５〜４０、松村宏，軽部征夫 |
| 遺伝 ４３［１］ （１９８９−１−１） Ｐ．２５〜２９、松村宏 |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH02228538A (en) | 1990-09-11 |
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