JPH05312709A - Gas sensor using piezoelectric element and measuring method of concentration of gas using the gas sensor - Google Patents
Gas sensor using piezoelectric element and measuring method of concentration of gas using the gas sensorInfo
- Publication number
- JPH05312709A JPH05312709A JP13966792A JP13966792A JPH05312709A JP H05312709 A JPH05312709 A JP H05312709A JP 13966792 A JP13966792 A JP 13966792A JP 13966792 A JP13966792 A JP 13966792A JP H05312709 A JPH05312709 A JP H05312709A
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- gas
- film
- piezoelectric element
- difference
- frequency
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Abstract
Description
【０００１】[0001]
【産業上の利用分野】この発明は、有機分子へのガスの
吸着量（ガス濃度）を、圧電素子を含む発振回路の周波
数変化として検出する圧電素子を用いたガスセンサおよ
びこれを用いたガス濃度測定方法に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas sensor using a piezoelectric element for detecting an adsorption amount (gas concentration) of a gas on an organic molecule as a frequency change of an oscillation circuit including the piezoelectric element, and a gas concentration using the same. It relates to a measuring method.
【０００２】[0002]
【従来の技術】図７は、例えばヴェネマら，「アイ・ト
リプル・イー（ＩＥＥＥ）会報・超音波、フェロエレク
トリクスおよび周波数制御」，第ＵＦＦＣ−３４巻，第
２号，第148-155 頁（1987年）（A.Venema et al,"IEEE
Transactions on Ultrasonics, Ferroelectrics and F
requency Control",Vol.UFFC-34,No.2,pp.148-155(198
7))に示された従来のガスセンサの構成を示す説明図で
あり、図において、１は２本の遅延線６ａ，６ｂを具備
するＳＡＷ（Surface Acoustics Wave；表面弾性波）素
子（圧電素子の一種）、２は薄い有機膜、１ａは有機膜
２で被覆された遅延線６ａを具備するＳＡＷ素子部分、
１ｂは有機膜のついていない遅延線６ｂを具備するＳＡ
Ｗ素子部分、３ａ，３ｂはそれぞれＳＡＷ素子部分１
ａ，１ｂに接続する増幅器、４ａ，４ｂは音響制御回
路、５は２本の遅延線６ａ，６ｂから送られる２つの音
響信号の周波数差を検出する周波数差演算装置である。
有機膜２としては、例えば金属フリー（「金属を含まな
い」の意）のフタロシアニン（ＰＣ）有機半導体膜を用
いる。2. Description of the Related Art FIG. 7 shows, for example, Venema et al., "I Triple Triple (IEEE) Bulletin: Ultrasound, Ferroelectrics and Frequency Control", UFFC-34, No. 2, pp. 148-155. (1987) (A. Venema et al, "IEEE
Transactions on Ultrasonics, Ferroelectrics and F
requency Control ", Vol.UFFC-34, No.2, pp.148-155 (198
7)) is an explanatory view showing the configuration of the conventional gas sensor shown in FIG. 1, in which 1 is a SAW (Surface Acoustics Wave) element (piezoelectric element) having two delay lines 6a and 6b. 1), 2 is a thin organic film, 1a is a SAW element portion including a delay line 6a covered with the organic film 2,
1b is an SA having a delay line 6b without an organic film.
W element portions 3a and 3b are SAW element portions 1 respectively
Amplifiers connected to a and 1b, 4a and 4b are acoustic control circuits, and 5 is a frequency difference calculation device for detecting a frequency difference between two acoustic signals sent from the two delay lines 6a and 6b.
As the organic film 2, for example, a metal-free (meaning “containing no metal”) phthalocyanine (PC) organic semiconductor film is used.
【０００３】つぎに動作について説明する。音響制御回
路から送られる音響信号は、２本の遅延線６ａ，６ｂに
至るが、ここで２つのＳＡＷ遅延線６ａ，６ｂは、増幅
器３とともに発信機を構成し、各遅延線６ａ，６ｂに対
応する２種の出力信号を送り出す。Next, the operation will be described. The acoustic signal sent from the acoustic control circuit reaches the two delay lines 6a and 6b. Here, the two SAW delay lines 6a and 6b constitute a transmitter together with the amplifier 3 and are connected to the delay lines 6a and 6b. It sends out two corresponding output signals.
【０００４】そして、このガスセンサを窒素ガス雰囲気
下に設置したときは、窒素ガスは遅延線１ａ上の有機膜
２および遅延線１ｂ上のいずれにも吸着しないため、こ
れらの遅延線を含む発信機の２つの出力信号はいずれも
周波数が変化せず、したがって両者の間には発振周波数
の差は見られない。When the gas sensor is installed in a nitrogen gas atmosphere, the nitrogen gas is not adsorbed on either the organic film 2 on the delay line 1a or on the delay line 1b, so that the transmitter including these delay lines. The frequency of the two output signals does not change, so that no difference in the oscillation frequency is seen between them.
【０００５】ところが、このガスセンサをＮＯ2 ガスの
存在するところに設置すると、上述のＰＣ膜２にはＮＯ
2 ガス分子が吸着し始めるが、膜のない遅延線６ｂに
は、この吸着が起こりにくい。すると、ＰＣ膜２と遅延
線６ａの間の化学界面では物理的性質が変化し、導電率
に変化が起こる。よって、この両遅延線６ａ，６ｂ間の
ＮＯ2 ガス吸着量の差は、両遅延線（音響路）を通る電
流の位相速度に差を生じさせ、その結果発信機からの２
つの出力信号の周波数に差が生まれる。この場合、遅延
線６ｂは参照用となる。遅延線６ｂには、いかなるガス
も吸着しない。However, if this gas sensor is installed in the presence of NO 2 gas, NO will be present on the PC film 2 described above.
2 Gas molecules start to be adsorbed, but this adsorption is less likely to occur on the delay line 6b having no film. Then, the physical properties change at the chemical interface between the PC film 2 and the delay line 6a, and the conductivity changes. Therefore, the difference in the amount of NO 2 gas adsorption between the delay lines 6a and 6b causes a difference in the phase velocity of the current passing through the delay lines (acoustic paths), resulting in a 2
A difference is created in the frequencies of the two output signals. In this case, the delay line 6b is for reference. No gas is adsorbed on the delay line 6b.
【０００６】そして、ＮＯ2 ガスの濃度とそのＰＣ膜２
への吸着量の間には相関関係があり、またこのＮＯ2 ガ
ス吸着量と上述の発振周波数差との間にも相関があるこ
とから、この発振周波数差を計測することによりＮＯ2
のガス濃度を測定することができる。Then, the concentration of NO 2 gas and its PC film 2
Since there is a correlation between the adsorbed amount of NO 2 and the adsorbed amount of NO 2 gas and the above-mentioned oscillation frequency difference, NO 2 is measured by measuring this oscillation frequency difference.
The gas concentration of can be measured.
【０００７】[0007]
【発明が解決しようとする課題】従来の圧電素子を利用
したガスセンサおよびこれを用いたガス濃度測定方法
は、測定対象のガスを吸着する有機分子膜をもった圧電
素子とこの膜をもたない圧電素子の間の発振周波数差を
計測するように構成されているが、この有機膜には測定
対象となるガス以外のガスも吸着することが避けられな
いため、ガスの選択性が低いという問題点があった。ま
た、測定対象ガス以外のガスの濃度変動によっても応答
が変動するため、Ｓ／Ｎ比が悪くなり、高感度にできな
いという問題点があった。A conventional gas sensor using a piezoelectric element and a gas concentration measuring method using the same do not have a piezoelectric element having an organic molecular film for adsorbing a gas to be measured and this film. Although it is configured to measure the oscillation frequency difference between the piezoelectric elements, it is inevitable that gases other than the gas to be measured are adsorbed to this organic film, so the gas selectivity is low. There was a point. Further, the response also fluctuates due to fluctuations in the concentration of gases other than the gas to be measured, so the S / N ratio deteriorates, and there is the problem that high sensitivity cannot be achieved.
【０００８】この発明は上記のような問題点を解消する
ためになされたもので、ガス種の選択性が高く、また高
感度な圧電素子を用いたガスセンサおよびこれを使用す
るガス濃度測定方法を得ることを目的とする。The present invention has been made to solve the above problems, and provides a gas sensor using a piezoelectric element having high gas species selectivity and high sensitivity, and a gas concentration measuring method using the same. The purpose is to get.
【０００９】[0009]
【課題を解決するための手段】請求項１に記載の発明に
係る圧電素子を用いたガスセンサは、特定のガスに対し
て他のガスよりも高い吸着特性を示す選択的吸着性有機
膜を担持した圧電素子と、ガスを非選択的に吸着する非
選択的吸着性有機膜を担持した圧電素子と、これら両圧
電素子に音響信号を与える音響制御手段と、上記両圧電
素子の発振周波数の差を検出する周波数差検出手段を有
するものである。A gas sensor using a piezoelectric element according to a first aspect of the present invention carries a selective adsorptive organic film exhibiting a higher adsorption characteristic for a specific gas than other gases. The piezoelectric element, a piezoelectric element carrying a non-selective adsorptive organic film that non-selectively adsorbs gas, an acoustic control means for giving an acoustic signal to these piezoelectric elements, and a difference in oscillation frequency between the piezoelectric elements. It has a frequency difference detecting means for detecting.
【００１０】さらに請求項２に記載の発明に係るガス濃
度測定方法は、特定のガスに対して他のガスよりも高い
吸着特性を示す選択的吸着性有機膜を担持した圧電素子
の発振周波数を測定する工程と、ガスを非選択的に吸着
する非選択的吸着性有機膜を担持した圧電素子の発振周
波数を測定する工程と、上記両工程で測定された発振周
波数の差を求める工程を含むものである。Further, in the gas concentration measuring method according to the invention of claim 2, the oscillation frequency of the piezoelectric element carrying the selective adsorptive organic film exhibiting higher adsorption characteristics for a specific gas than other gases is determined. It includes a step of measuring, a step of measuring the oscillation frequency of a piezoelectric element carrying a non-selective adsorptive organic film that non-selectively adsorbs a gas, and a step of obtaining a difference between the oscillation frequencies measured in the both steps. It is a waste.
【００１１】[0011]
【作用】この発明における圧電素子を用いたガスセンサ
およびこれを使用するガス濃度測定方法は、特定のガス
に対して他のガスよりも高い吸着特性を示す選択的吸着
性有機膜を担持した圧電素子の発振周波数と、ガスを非
選択的に吸着する非選択的吸着性有機膜を担持した圧電
素子の発振周波数をそれぞれ測定し、上記両工程で測定
された発振周波数の差を求めるため、特定のガス以外の
ガス（測定対象以外のガス）については、選択的吸着性
有機膜と非選択的吸着性有機膜の同等な吸着特性をそれ
ぞれの周波数差を計測することにより相殺し、測定対象
とするガスだけを選択性よく、また高感度に計測するこ
とができる。A gas sensor using a piezoelectric element and a gas concentration measuring method using the same according to the present invention are directed to a piezoelectric element carrying a selective adsorptive organic film exhibiting a higher adsorption characteristic for a specific gas than other gases. And the oscillating frequency of the piezoelectric element carrying the non-selective adsorptive organic film that non-selectively adsorbs the gas, and obtains the difference between the oscillating frequencies measured in the above two steps. For gases other than gases (gases other than the measurement target), the equivalent adsorption characteristics of the selective adsorptive organic film and the non-selective adsorptive organic film are offset by measuring the frequency difference between them, and are taken as the measurement object. Only gas can be measured with high selectivity and high sensitivity.
【００１２】[0012]
実施例１．以下この発明の一実施例を図について説明す
る。図１はこの実施例に係るＮＯ2 ガスセンサの構成図
であり、図１において１１ａ，１１ｂはＡＴカットで９
MHz を基本発振周波数とする水晶振動子（圧電素子）、
１２は水晶振動子１１ａ上に形成したＮＯ2 ガス選択吸
着膜（他のガスにもわずかに感応する）として機能する
テトラフェニルポルフィリンコバルト錯体膜、１３は水
晶振動子１１ｂ上に形成したＮＯ2 ガスに対して選択吸
着を示さない（ガスを種類を問わずわずかに吸着する）
非選択吸着膜として機能するテトラフェニルポルフィリ
ン亜鉛錯体膜、１４は水晶振動子を発振させるための発
振回路、１５は周波数カウンタ、１６は水晶振動子１１
ａ，１１ｂの発振周波数差を計算する周波数差演算装
置、１６ａは演算装置１６の出力信号である。Example 1. An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of the NO 2 gas sensor according to this embodiment. In FIG. 1, 11a and 11b are AT-cut 9
Crystal oscillator (piezoelectric element) whose fundamental oscillation frequency is MHz,
12 is a tetraphenylporphyrin-cobalt complex film that functions as an NO 2 gas selective adsorption film (slightly sensitive to other gases) formed on the crystal unit 11a, and 13 is NO 2 gas formed on the crystal unit 11b. Does not show selective adsorption (adsorbs gas slightly regardless of type)
Tetraphenylporphyrin zinc complex film that functions as a non-selective adsorption film, 14 an oscillation circuit for oscillating a quartz oscillator, 15 a frequency counter, and 16 a quartz oscillator 11
Reference numeral 16a denotes an output signal of the arithmetic unit 16 for calculating a difference in oscillation frequency between a and 11b.
【００１３】このガスセンサの動作は、先に図７につい
て説明したものとほぼ同じであり、発振回路１４からの
信号によって水晶振動子１１ａ，１１ｂが発振し、各水
晶振動子１１ａ，１１ｂに対応する２種の信号が発生す
るが、２種の有機膜１２，１３はＮＯ2 ガスに対する吸
着能が異なるため、ＮＯ2 ガスに触れさせたときは、先
に図７で説明したように、有機膜１２と水晶振動子１１
ａの間の界面の物理特性が変化して水晶振動子１１ａの
導電率に影響を与え、水晶振動子１１ａを流れる電流の
位相速度、ひいては周波数に変化が生まれる。なお、Ｎ
Ｏ2 ガス以外のガスは、有機膜１２，１３にわずかに吸
着するものの、２つの有機膜１２，１３間で吸着量には
ほとんど差がない。よって、水晶振動子１１ａ，１１ｂ
の発振周波数には変化が生ずるものの、その変化は同じ
程度で両者の周波数に差は生まれない。The operation of this gas sensor is almost the same as that described above with reference to FIG. 7, and the crystal oscillators 11a and 11b oscillate in response to the signal from the oscillation circuit 14 and correspond to the respective crystal oscillators 11a and 11b. two signals are generated, but since the two organic films 12 and 13 that the adsorption capacity for NO 2 gas different, when exposed to the NO 2 gas, as described in Figure 7 above, the organic film 12 and crystal unit 11
The physical characteristics of the interface between the a and the a change affect the conductivity of the crystal unit 11a, and the phase velocity of the current flowing through the crystal unit 11a and thus the frequency change. Note that N
Gases other than O 2 gas are slightly adsorbed on the organic films 12 and 13, but there is almost no difference in the adsorption amount between the two organic films 12 and 13. Therefore, the crystal units 11a and 11b
Although there is a change in the oscillating frequency, the change is about the same and there is no difference in both frequencies.
【００１４】両水晶振動子１１ａ，１１ｂの発振周波数
は周波数カウンタ１５によって計数される。そして、こ
の計数された各周波数は、周波数差演算装置１６で両者
間の周波数差を演算され、ＮＯ2 ガス濃度算出のための
出力信号１６ａとしてガスセンサ外部に送り出される。The oscillation frequencies of both crystal oscillators 11a and 11b are counted by a frequency counter 15. The frequency difference calculator 16 calculates the frequency difference between the counted frequencies, and the signal is sent to the outside of the gas sensor as an output signal 16a for calculating the NO 2 gas concentration.
【００１５】有機分子膜１２，１３の形成は、真空蒸着
法を用いて行い、テトラフェニルポルフィリンコバルト
錯体およびテトラフェニルポルフィリン亜鉛錯体は、必
要に応じ生成して用いた。蒸着の膜厚は両者１２，１３
ともに５００Ａであった。また、このガスセンサを用い
たガス濃度の測定は、フロー方式により行い、最初ＮＯ
2 、ＣＯ2 、Ｈ2 Ｏおよびｎ−ブタンを含まない空気を
流し、ついでＮＯ2 、ＣＯ2 、Ｈ2 Ｏおよびｎ−ブタン
を含む空気に切り換えることによりＮＯ2 のガス濃度を
測定した。The organic molecular films 12 and 13 were formed by using a vacuum vapor deposition method, and the tetraphenylporphyrin cobalt complex and the tetraphenylporphyrin zinc complex were formed and used as needed. The film thickness of vapor deposition is 12, 13 for both.
Both were 500A. In addition, the gas concentration measurement using this gas sensor is performed by the flow method, and the NO
2, CO 2, H 2 flow of O and air containing no n- butane, then measure the gas concentration of NO 2 by switching the air containing NO 2, CO 2, H 2 O and n- butane.
【００１６】図２（ａ）は、テトラフェニルポルフィリ
ンコバルト錯体膜１２とテトラフェニルポルフィリン亜
鉛錯体膜１３のＮＯ2 その他のガスの吸着に係る各水晶
振動子１１ａ，１１ｂの経時的な周波数変化を示したグ
ラフ図であり、図中１７はテトラフェニルポルフィリン
コバルト錯体膜１２の応答曲線（ガス吸着曲線）、１８
はテトラフェニルポルフィリン亜鉛錯体膜１３の応答曲
線である。また図２（ｂ）はこれら周波数の差（応答曲
線１７と１８の差）を示すグラフ図である。FIG. 2 (a) shows a time-dependent change in frequency of each of the crystal resonators 11a and 11b associated with adsorption of NO 2 and other gases on the tetraphenylporphyrin-cobalt complex film 12 and the tetraphenylporphyrin-zinc complex film 13. 17 is a graph showing the response curve (gas adsorption curve) of the tetraphenylporphyrin cobalt complex film 12;
Is a response curve of the tetraphenylporphyrin zinc complex film 13. 2B is a graph showing the difference between these frequencies (the difference between the response curves 17 and 18).
【００１７】図２（ａ）の応答曲線１７において、テト
ラフェニルポルフィリンコバルト錯体膜１２のガス吸着
特性の経時変化は、選択吸着性の高いＮＯ2 を始め、選
択吸着能の低いＨ2 Ｏ、ｎ−ブタン、ＣＯ2 吸着による
応答の和として得られている。テトラフェニルポルフィ
リンコバルト錯体膜１２のＮＯ2 ガスに対する感応速度
はきわめて高いことが分る。一方、応答曲線１８に表さ
れるように、テトラフェニルポルフィリン亜鉛錯体膜１
３の吸着特性の経時変化は、ＮＯ2 に対する選択的吸着
性が低いため、応答の立ち上がりがテトラフェニルポル
フィリンコバルト錯体と比べて遅く、周波数変化も小さ
くなっている。In the response curve 17 of FIG. 2A, the gas adsorption characteristics of the tetraphenylporphyrin cobalt complex film 12 change with time, including NO 2 having a high selective adsorption property, and H 2 O, n having a low selective adsorption ability. -Butane, obtained as the sum of responses due to CO 2 adsorption. It can be seen that the sensitivity rate of the tetraphenylporphyrin cobalt complex film 12 to NO 2 gas is extremely high. On the other hand, as shown in the response curve 18, the tetraphenylporphyrin zinc complex film 1
With respect to the change with time of the adsorption characteristic of No. 3, since the selective adsorption property to NO 2 is low, the rise of the response is slower than that of the tetraphenylporphyrin cobalt complex and the frequency change is small.
【００１８】そして、図２（ｂ）に示すこのガスセンサ
の応答はＮＯ2 濃度に基づくもののみとなり、選択性が
よく、また他のガスの濃度変動に起因する変動も相殺さ
れ、Ｓ／Ｎ比の高い高感度な応答が得られることにな
る。The response of this gas sensor shown in FIG. 2 (b) is based only on the NO 2 concentration, and the selectivity is good, and the variation due to the variation in the concentration of other gases is offset, and the S / N ratio is reduced. It is possible to obtain a highly sensitive and highly sensitive response.
【００１９】実施例２．つぎにこの発明の他の実施例に
係るｎ−ブタンガスセンサを図３について説明する。図
において、１４〜１６ａは図１と同じであり、１１ｃ，
１１ｄは水晶振動子、２０はラングムア−ブロジェット
（Langmuir-Blodgett;ＬＢ）法により水晶振動子１１ｃ
上に形成したヘマトポルフィリン（IX）−ビス（トリデ
カノイルエーテル）ルテニウムジピリジン錯体（以下
「RuHP(py)2 」と略す）の累積膜、２１は同じくＬＢ法
により水晶振動子１１ｄ上に形成したω−トリコセン酸
ＬＢ累積膜（「ＬＢ膜」ともいう）である。ω−トリコ
セン酸ＬＢ累積膜は、ｎ−ブタンを含む炭化水素ガスに
対して選択吸着性を示す膜であり、他方RuHP(py)2 累積
膜は非選択性吸着膜である。このガスセンサの動作は、
実施例１のガスセンサの動作と同じである。Example 2. Next, an n-butane gas sensor according to another embodiment of the present invention will be described with reference to FIG. In the figure, 14 to 16a are the same as those in FIG.
Reference numeral 11d is a crystal resonator, and 20 is a crystal resonator 11c by a Langmuir-Blodgett (LB) method.
Cumulative film of hematoporphyrin (IX) -bis (tridecanoyl ether) ruthenium dipyridine complex (hereinafter abbreviated as "RuHP (py) 2 ") formed above, 21 is also formed on the crystal resonator 11d by the LB method. Ω-tricosenoic acid LB cumulative film (also referred to as “LB film”). The ω-tricosenoic acid LB cumulative film is a film that exhibits selective adsorption to a hydrocarbon gas containing n-butane, while the RuHP (py) 2 cumulative film is a non-selective adsorption film. The operation of this gas sensor is
The operation is the same as that of the gas sensor of the first embodiment.
【００２０】ＬＢ累積膜２０，２１の成膜方法について
説明すると、まずRuHP(py)2 ＬＢ累積膜２０の場合は、
RuHP(py)2 のクロロホルム溶液１mMを１０-4ＭのＢａＣ
ｌ2溶液（ｐＨ７、１２℃）に展開し、ＬＢ膜製造装置
により膜圧が１５mNcm-1となるように膜を圧縮した。そ
して垂直浸漬法により、水晶振動子１１ｃ上にRuHP(py)
2 ＬＢ膜２０を数層〜数十層累積した。A method of forming the LB cumulative films 20 and 21 will be described. First, in the case of the RuHP (py) 2 LB cumulative film 20,
1 mM of RuHP (py) 2 in chloroform was added with 10 -4 M of BaC.
Expand the l 2 solution (pH7,12 ℃), it was compressed film so film thickness becomes 15MNcm -1 by LB film manufacturing apparatus. Then, RuHP (py) is placed on the crystal unit 11c by the vertical immersion method.
2 to several tens of LB films 20 were accumulated.
【００２１】一方、ω−トリコセン酸ＬＢ膜２１の場合
は、ω−トリコセン酸１mMのクロロホルム溶液を１０-4
ＭのＢａＣｌ2 溶液に（ｐＨ７、１２℃）に展開し、Ｌ
Ｂ膜製造装置にて膜圧が３０mNcm-1となるように膜を圧
縮した。そして垂直浸漬法により、水晶振動子１１ｄ上
にω−トリコセン酸ＬＢ膜２１を数層〜数十層累積し
た。累積後はDeepＵＶランプでＬＢ膜を照射し、ω−ト
リコセン酸を重合させた。On the other hand, in the case of the ω-tricosenoic acid LB film 21, a chloroform solution of 1 mM of ω-tricosenoic acid was added to 10 -4.
M BaCl 2 solution (pH7, 12 ℃)
The membrane was compressed by a B membrane manufacturing apparatus so that the membrane pressure became 30 mNcm -1 . Then, several to several tens layers of the ω-tricosenoic acid LB film 21 were accumulated on the crystal resonator 11d by the vertical dipping method. After the accumulation, the LB film was irradiated with a Deep UV lamp to polymerize ω-tricosenoic acid.
【００２２】この実施例においては、ＮＯ2 、ＣＯ2 お
よびＨ2 Ｏを含まない空気からＮＯ2 、ＣＯ2 およびＨ
2 Ｏを含む空気に切り換えるフロー方式でガス濃度の測
定を行った。図４（ａ）は、RuHP(py)2 膜２０および重
合したω−トリコセン酸ＬＢ膜（以下単に「ω−トリコ
セン酸ＬＢ膜」という）２１に係る各ガス吸着曲線２
２，２３を示すグラフ図であり、図４（ｂ）はこれら２
つのガス吸着曲線２２，２３の差（すなわち、水晶振動
子１１ｃ，１１ｄの発振周波数の差）を示すグラフ図で
ある。In this example, NO 2 , CO 2 and H 2 O-free air was used to remove NO 2 , CO 2 and H 2.
The gas concentration was measured by a flow method in which the air was switched to air containing 2 O. FIG. 4A shows each gas adsorption curve 2 for the RuHP (py) 2 film 20 and the polymerized ω-tricosenoic acid LB film (hereinafter simply referred to as “ω-tricosenoic acid LB film”) 21.
2 and 23 are graphs showing 2 and 23, and FIG.
It is a graph which shows the difference of two gas adsorption curves 22 and 23 (namely, the difference of the oscillation frequency of crystal oscillators 11c and 11d).
【００２３】この実施例では、測定に使用するガスがｎ
−ブタンを含まないため、図４（ａ）においては専らRu
HP(py)2 膜２０のＮＯ2 に対する応答だけが際立って観
察される。なお、ガス吸着曲線２２，２３はいずれもＣ
Ｏ2 およびＨ2 Ｏに対する同程度の応答を含むものであ
る。そして、図４（ｂ）に示すように、両ガス吸着曲線
の差を計算することにより、高選択性でかつ高感度なＮ
Ｏ2 測定結果が得られる。In this embodiment, the gas used for measurement is n
-Because it does not contain butane, it is exclusively Ru in FIG.
Only the response of HP (py) 2 film 20 to NO 2 is noticeably observed. The gas adsorption curves 22 and 23 are both C
It contains comparable responses to O 2 and H 2 O. Then, as shown in FIG. 4B, by calculating the difference between the two gas adsorption curves, N with high selectivity and high sensitivity can be obtained.
O 2 measurement results are obtained.
【００２４】実施例３．この発明のさらに他の実施例に
係るガスセンサを図５について説明する。図において、
１１ａ，１１ｂ，１１ｄ，１２〜１５は図１、図３にお
けるものと同じであり、３０，３１は先の１６と同様の
周波数差演算装置、３０ａ，３１ａはそれぞれ周波数差
演算装置３０，３１の出力信号である。また、各有機膜
１２，１３，２１の形成方法は実施例１および２と同じ
である。Example 3. A gas sensor according to another embodiment of the present invention will be described with reference to FIG. In the figure,
11a, 11b, 11d, 12 to 15 are the same as those in FIG. 1 and FIG. 3, 30 and 31 are frequency difference calculation devices similar to the above 16, and 30a and 31a are frequency difference calculation devices 30 and 31, respectively. It is an output signal. The method of forming each organic film 12, 13, 21 is the same as in the first and second embodiments.
【００２５】このガスセンサは、テトラフェニルポルフ
ィリンコバルト錯体膜１２とテトラフェニルポルフィリ
ン亜鉛錯体膜１３をそれぞれ形成した水晶振動子１１
ａ，１１ｂ間の周波数差（「周波数差Ａ」とする）と、
ω−トリコセン酸ＬＢ膜２１を形成した水晶振動子１１
ｄと水晶振動子１１ｂの間の周波数差（「周波数差Ｂ」
とする）を同時に計測するように構成する。周波数差Ａ
は周波数差演算装置３０で、また周波数差Ｂは周波数差
演算装置３１でそれぞれ算出し、出力信号３０ａ，３１
ａとしてそれぞれ出力する。このガスセンサの動作は実
施例１および２のガスセンサと同じであり、したがって
このガスセンサは、ＮＯ2 ガスと炭化水素ガスの複数の
ガスを検出できる多成分ガスセンサとなる。This gas sensor has a crystal oscillator 11 in which a tetraphenylporphyrin cobalt complex film 12 and a tetraphenylporphyrin zinc complex film 13 are formed, respectively.
a frequency difference between a and 11b (referred to as "frequency difference A"),
Quartz resonator 11 having ω-tricosenoic acid LB film 21 formed
d and the frequency difference between the crystal unit 11b (“frequency difference B”)
And) are simultaneously measured. Frequency difference A
Is calculated by the frequency difference calculator 30 and the frequency difference B is calculated by the frequency difference calculator 31.
Output as a. The operation of this gas sensor is the same as that of the gas sensors of Examples 1 and 2, and therefore, this gas sensor is a multi-component gas sensor capable of detecting a plurality of NO 2 gas and hydrocarbon gas.
【００２６】この実施例においては、実施例１と同様
に、ＮＯ2 、ＣＯ2 、Ｈ2 Ｏおよびｎ−ブタンを含まな
い空気からＮＯ2 、ＣＯ2 、Ｈ2 Ｏおよびｎ−ブタンを
含む空気に切り換えるフロー方式でガス濃度の測定を行
った。図６は、周波数差Ａと周波数差Ｂをそれぞれ表す
曲線２５と２６を示すグラフ図である。この図によれ
ば、周波数差ＡとＢについて、それぞれ図２（ｂ）およ
び図４（ｂ）に似通った曲線が得られている。よって、
ＮＯ2 ガスおよびｎ−ブタン（炭化水素）について、た
だ一個のガスセンサにより、同時に、複数のガス種を高
選択性かつ高感度をもって濃度を測定できることが分
る。[0026] Air In this example, similarly to Example 1, comprising NO 2, CO 2, H 2 O and n- butane from free air NO 2, CO 2, H 2 O and n- butane The gas concentration was measured by the flow method of switching to. FIG. 6 is a graph showing curves 25 and 26 representing the frequency difference A and the frequency difference B, respectively. According to this figure, for the frequency differences A and B, curves similar to those in FIGS. 2B and 4B are obtained. Therefore,
It can be seen that, for NO 2 gas and n-butane (hydrocarbon), the concentration of a plurality of gas species can be simultaneously measured with high selectivity and high sensitivity by using only one gas sensor.
【００２７】なお上記各実施例のガスセンサにおいて
は、３個までの有機分子膜と水晶振動子を組合せ、１個
の水晶振動子を基準とした時の他の１個または２個の水
晶振動子との周波数差を計測するように構成したが、さ
らに多くの有機分子膜をもった水晶振動子を用い、３種
以上のガスを同時に測定することもできる。また上記各
実施例では圧電素子として水晶振動子を用いたが、これ
をＳＡＷ素子その他の圧電素子に置き換えても同様の効
果を奏する。In the gas sensor of each of the above embodiments, up to three organic molecular films and a crystal oscillator are combined, and one or two other crystal oscillators when one crystal oscillator is used as a reference. Although it was configured to measure the frequency difference between the above and the above, it is possible to simultaneously measure three or more kinds of gases by using a quartz oscillator having a larger number of organic molecular films. Further, in each of the above-described embodiments, the crystal oscillator is used as the piezoelectric element, but the same effect can be obtained even if the crystal oscillator is replaced with a SAW element or other piezoelectric elements.
【００２８】[0028]
【発明の効果】以上のように、この発明によれば、特定
のガスに対して高い吸着特性を示すことのない非選択的
吸着性有機膜を担持した圧電素子と、特定のガスに対し
て高い吸着特性を示す選択的吸着性有機膜を担持した圧
電素子の各出力信号における発振周波数の差を計測する
ように構成したので、選択性にすぐれ、しかも感度の高
いガスセンサおよびガス濃度測定方法が得られる。As described above, according to the present invention, a piezoelectric element carrying a non-selective adsorptive organic film that does not exhibit high adsorption characteristics for a specific gas, and a specific gas Since it is configured to measure the difference in the oscillation frequency in each output signal of the piezoelectric element carrying the selectively adsorbing organic film exhibiting high adsorption characteristics, a gas sensor and a gas concentration measuring method with excellent selectivity and high sensitivity are provided. can get.
【図１】この発明の一実施例によるガスセンサの構成図
である。FIG. 1 is a configuration diagram of a gas sensor according to an embodiment of the present invention.
【図２】（ａ）は図１のガスセンサにおける２つの圧電
素子の発振周波数を示すグラフ図である。（ｂ）は
（ａ）における各発振周波数の差を示すグラフ図であ
る。FIG. 2 (a) is a graph showing oscillation frequencies of two piezoelectric elements in the gas sensor of FIG. (B) is a graph showing the difference between the oscillation frequencies in (a).
【図３】この発明の他の実施例によるガスセンサの構成
図である。FIG. 3 is a configuration diagram of a gas sensor according to another embodiment of the present invention.
【図４】（ａ）は図３のガスセンサにおける２つの圧電
素子の発振周波数を示すグラフ図である。（ｂ）は
（ａ）における各発振周波数の差を示すグラフ図であ
る。FIG. 4A is a graph showing oscillation frequencies of two piezoelectric elements in the gas sensor of FIG. (B) is a graph showing the difference between the oscillation frequencies in (a).
【図５】この発明のさらに他の実施例による多成分検出
ガスセンサの構成図である。FIG. 5 is a configuration diagram of a multi-component detection gas sensor according to still another embodiment of the present invention.
【図６】図５のガスセンサのＮＯ2 とｎ−ブタンに対す
る応答曲線を示すグラフ図である。FIG. 6 is a graph showing a response curve of the gas sensor of FIG. 5 to NO 2 and n-butane.
【図７】従来のガスセンサの構成図である。FIG. 7 is a configuration diagram of a conventional gas sensor.
【符号の説明】 １１ａ，１１ｂ，１１ｃ，１１ｄ 水晶振動子（圧電素
子） １２ テトラフェニルポルフィリンコバルト錯体膜（選
択的吸着性有機膜） １３ テトラフェニルポルフィリン亜鉛錯体膜（非選択
的吸着性有機膜） １４ 発振回路（音響制御手段） １５ 周波数カウンタ（周波数差検出手段） １６，３０，３１ 周波数差演算装置（周波数差検出手
段）[Explanation of Codes] 11a, 11b, 11c, 11d Crystal resonator (piezoelectric element) 12 Tetraphenylporphyrin cobalt complex film (selective adsorbing organic film) 13 Tetraphenylporphyrin zinc complex film (nonselective adsorbing organic film) 14 Oscillation circuit (acoustic control means) 15 Frequency counter (frequency difference detection means) 16, 30, 31 Frequency difference calculation device (frequency difference detection means)
─────────────────────────────────────────────────────
─────────────────────────────────────────────────── ───
【手続補正書】[Procedure amendment]
【提出日】平成４年８月１９日[Submission date] August 19, 1992
【手続補正１】[Procedure Amendment 1]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】０００５[Correction target item name] 0005
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【０００５】ところが、このガスセンサをＮＯ2 ガスの
存在するところに設置すると、上述のＰＣ膜２にはＮＯ
2 ガス分子が吸着し始めるが、膜のない遅延線６ｂに
は、この吸着が起こりにくい。すると、ＰＣ膜２の表面
ではガスの選択的な吸着により、遅延線上のＰＣ膜の質
量が変化し、表面弾性波の伝搬状態に変化が起こる。よ
ってこの両遅延線６ａ，６ｂ間のＮＯ2 ガス吸着量の差
は、両遅延線（音響路）を伝搬する音響波の位相速度に
差を生じさせ、その結果発信機からの２つの出力信号の
周波数に差が生まれる。この場合、遅延線６ｂは参照用
となる。遅延線６ｂには、いかなるガスも吸着しない。However, if this gas sensor is installed in the presence of NO 2 gas, NO will be present on the PC film 2 described above.
2 Gas molecules start to be adsorbed, but this adsorption is less likely to occur on the delay line 6b having no film. Then, the surface of the PC film 2
Then, due to the selective adsorption of gas, the quality of the PC film on the delay line
The amount changes, and the propagation state of the surface acoustic wave changes. Yo
Therefore, the difference in the amount of NO 2 gas adsorption between these delay lines 6a and 6b
Causes a difference in the phase velocities of the acoustic waves propagating through both delay lines (acoustic paths), resulting in a difference in the frequencies of the two output signals from the transmitter. In this case, the delay line 6b is for reference. No gas is adsorbed on the delay line 6b.
【手続補正２】[Procedure Amendment 2]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】００１３[Correction target item name] 0013
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【００１３】このガスセンサの動作は、先に図７につい
て説明したものとほぼ同じであり、発振回路１４からの
信号によって水晶振動子１１ａ，１１ｂが発振し、各水
晶振動子１１ａ，１１ｂに対応する２種の信号が発生す
るが、２種の有機膜１２，１３はＮＯ2 ガスに対する吸
着能が異なるため、ＮＯ2 ガスに触れさせたときは、先
に図７で説明したように、有機膜１２の表面にガスの吸
着が生じ、有機膜１２の質量に変化が起こり、その結果
発振周波数に変化が生まれる。なお、ＮＯ2 ガス以外の
ガスは、有機膜１２，１３にわずかに吸着するものの、
２つの有機膜１２，１３間で吸着量にはほとんど差がな
い。よって、水晶振動子１１ａ，１１ｂの発振周波数に
は変化が生ずるものの、その変化は同じ程度で両者の周
波数に差は生まれない。The operation of this gas sensor is almost the same as that described above with reference to FIG. 7, and the crystal oscillators 11a and 11b oscillate in response to the signal from the oscillation circuit 14 and correspond to the respective crystal oscillators 11a and 11b. two signals are generated, but since the two organic films 12 and 13 that the adsorption capacity for NO 2 gas different, when exposed to the NO 2 gas, as described in Figure 7 above, the organic film Gas absorption on the surface of 12
Adhesion occurs, and the mass of the organic film 12 changes, resulting in
Changes occur in the oscillation frequency. Gases other than the NO 2 gas are slightly adsorbed on the organic films 12 and 13, but
There is almost no difference in the adsorption amount between the two organic films 12 and 13. Therefore, although the oscillation frequencies of the crystal oscillators 11a and 11b change, the changes are about the same and no difference occurs between the two frequencies.
【手続補正３】[Procedure 3]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】００１５[Correction target item name] 0015
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【００１５】有機分子膜１２，１３の形成は、真空蒸着
法を用いて行い、テトラフェニルポルフィリンコバルト
錯体およびテトラフェニルポルフィリン亜鉛錯体は、必
要に応じ精製して用いた。蒸着の膜厚は両者１２，１３
ともに５００Åであった。また、このガスセンサを用い
たガス濃度の測定は、フロー方式により行い、最初ＮＯ
2 、ＣＯ2 、ＣＯ、Ｈ2 Ｏおよびｎ−ブタンを含まない
空気を流し、ついでＮＯ2 、ＣＯ2 、ＣＯ、Ｈ2 Ｏおよ
びｎ−ブタンを含む空気に切り換えることによりＮＯ2
のガス濃度を測定した。The formation of the organic molecular films 12 and 13 was carried out by a vacuum vapor deposition method, and the tetraphenylporphyrin cobalt complex and the tetraphenylporphyrin zinc complex were used after purification if necessary. The film thickness of vapor deposition is 12, 13 for both.
Both were 500Å . In addition, the gas concentration measurement using this gas sensor is performed by the flow method, and the NO
2, CO 2, CO, flowing air containing no H 2 O and n- butane, then NO 2, CO 2, CO, NO 2 by switching the air containing H 2 O and n- butane
The gas concentration of was measured.
【手続補正４】[Procedure amendment 4]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】００１７[Correction target item name] 0017
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【００１７】図２（ａ）の応答曲線１７において、テト
ラフェニルポルフィリンコバルト錯体膜１２のガス吸着
特性の経時変化は、選択吸着性の高いＮＯ2 を始め、選
択吸着能の低いＨ2 Ｏ、ｎ−ブタン、ＣＯ2 、ＣＯ吸着
による応答の和として得られている。テトラフェニルポ
ルフィリンコバルト錯体膜１２のＮＯ2 ガスに対する感
応速度はきわめて高いことが分る。一方、応答曲線１８
に表されるように、テトラフェニルポルフィリン亜鉛錯
体膜１３の吸着特性の経時変化は、ＮＯ2 に対する選択
的吸着性が低いため、応答の立ち上がりがテトラフェニ
ルポルフィリンコバルト錯体と比べて遅く、周波数変化
も小さくなっている。In the response curve 17 of FIG. 2A, the gas adsorption characteristics of the tetraphenylporphyrin cobalt complex film 12 change with time, including NO 2 having a high selective adsorption property, and H 2 O, n having a low selective adsorption ability. - butane, are obtained as the sum of response by CO 2, CO adsorption. It can be seen that the sensitivity rate of the tetraphenylporphyrin cobalt complex film 12 to NO 2 gas is extremely high. On the other hand, the response curve 18
As shown in (4), the change over time in the adsorption characteristics of the tetraphenylporphyrin zinc complex film 13 is slower in the rise of response than the tetraphenylporphyrin cobalt complex and the frequency change due to the low selective adsorption of NO 2 . It is getting smaller.
【手続補正５】[Procedure Amendment 5]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】００１９[Name of item to be corrected] 0019
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【００１９】実施例２．つぎにこの発明の他の実施例に
係るＮＯ2 ガスセンサを図３について説明する。図にお
いて、１４〜１６ａは図１と同じであり、１１ｃ，１１
ｄは水晶振動子、２０はラングミュア−ブロジェット
（Langmuir-Blodgett;ＬＢ）法により水晶振動子１１ｃ
上に形成したヘマトポルフィリン（IX）−ビス（トリデ
カノイルエーテル）ルテニウムジピリジン錯体（以下
「RuHP(py)2 」と略す）の累積膜、２１は同じくＬＢ法
により水晶振動子１１ｄ上に形成したω−トリコセン酸
ＬＢ累積膜（「ＬＢ膜」ともいう）である。RuHP(py)2
累積膜はＮＯ2 およびｎ−ブタンを含む炭化水素ガスに
対して選択吸着性を示す膜であり、ω−トリコセン酸Ｌ
Ｂ累積膜は、ｎ−ブタンを含む炭化水素ガスに対して選
択吸着性を示す膜（炭化水素ガスに対してはRuHP(py)2
膜と同程度の選択吸着性をもつ）である。このガスセン
サの動作は、実施例１のガスセンサの動作と同じであ
る。Example 2. Next, an NO 2 gas sensor according to another embodiment of the present invention will be described with reference to FIG. In the figure, 14 to 16a are the same as those in FIG.
d is a crystal oscillator, 20 Lang Myu A - Blodgett; crystal resonator 11c by (Langmuir-Blodgett LB) method
Cumulative film of hematoporphyrin (IX) -bis (tridecanoyl ether) ruthenium dipyridine complex (hereinafter abbreviated as "RuHP (py) 2 ") formed above, 21 is also formed on the crystal resonator 11d by the LB method. Ω-tricosenoic acid LB cumulative film (also referred to as “LB film”). RuHP (py) 2
Cumulative film is used for hydrocarbon gas containing NO 2 and n-butane.
Is a film exhibiting selective adsorption to ω-tricosenoic acid L
The B accumulation film is a film showing selective adsorption to a hydrocarbon gas containing n-butane (RuHP (py) 2 for hydrocarbon gas).
It has the same level of selective adsorption as a membrane) . The operation of this gas sensor is the same as the operation of the gas sensor of the first embodiment.
【手続補正６】[Procedure Amendment 6]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】００２２[Name of item to be corrected] 0022
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【００２２】この実施例においては、ＮＯ2 、ＣＯ2 、
ＣＯ、ｎ−ブタンおよびＨ2 Ｏを含まない空気からＮＯ
2 、ＣＯ2 およびＨ2 Ｏを含む空気に切り換えるフロー
方式でガス濃度の測定を行った。図４（ａ）は、RuHP(p
y)2 膜２０および重合したω−トリコセン酸ＬＢ膜（以
下単に「ω−トリコセン酸ＬＢ膜」という）２１に係る
各ガス吸着曲線２２，２３を示すグラフ図であり、図４
（ｂ）はこれら２つのガス吸着曲線２２，２３の差（す
なわち、水晶振動子１１ｃ，１１ｄの発振周波数の差）
を示すグラフ図である。In this embodiment, NO 2 , CO 2 ,
NO from CO, n-butane and H 2 O free air
The gas concentration was measured by a flow method in which the air was switched to air containing 2 , CO 2, and H 2 O. Figure 4 (a) shows RuHP (p
FIG. 4 is a graph showing the gas adsorption curves 22 and 23 of the y film 2 and the polymerized ω-tricosenoic acid LB film (hereinafter simply referred to as “ω-tricosenoic acid LB film”) 21.
(B) shows the difference between these two gas adsorption curves 22 and 23 (that is, the difference between the oscillation frequencies of the crystal oscillators 11c and 11d).
It is a graph figure which shows.
【手続補正７】[Procedure Amendment 7]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】００２３[Name of item to be corrected] 0023
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【００２３】この実施例では、図４（ａ）においては専
らRuHP(py)2 膜２０のＮＯ2 に対する応答だけが際立っ
て観察される。なお、ガス吸着曲線２２，２３はいずれ
もＣＯ2 、ＣＯ、ｎ−ブタンおよびＨ2 Ｏに対する同程
度の応答を含むものである。そして、図４（ｂ）に示す
ように、両ガス吸着曲線の差を計算することにより、高
選択性でかつ高感度なＮＯ2 測定結果が得られる。In this embodiment, in FIG.
Only the response of RuHP (py) 2 film 20 to NO 2 is outstanding.
Be observed. It should be noted that the gas adsorption curves 22 and 23 both have similar responses to CO 2 , CO, n-butane and H 2 O. Then, as shown in FIG. 4B, the NO 2 measurement result with high selectivity and high sensitivity can be obtained by calculating the difference between both gas adsorption curves.
【手続補正８】[Procedure Amendment 8]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】００２６[Correction target item name] 0026
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【００２６】この実施例においては、実施例１と同様
に、ＮＯ2 、ＣＯ2 、ＣＯ、Ｈ2 Ｏおよびｎ−ブタンを
含まない空気からＮＯ2 、ＣＯ2 、ＣＯ、Ｈ2 Ｏおよび
ｎ−ブタンを含む空気に切り換えるフロー方式でガス濃
度の測定を行った。図６は、周波数差Ａと周波数差Ｂを
それぞれ表す曲線２５と２６を示すグラフ図である。こ
の図によれば、周波数差ＡとＢについて、それぞれ図２
（ｂ）および図４（ｂ）に似通った曲線が得られてい
る。よって、ＮＯ2 ガスおよびｎ−ブタン（炭化水素）
について、ただ一個のガスセンサにより、同時に、複数
のガス種を高選択性かつ高感度をもって濃度を測定でき
ることが分る。In this example, as in the case of Example 1, NO 2 , CO 2 , CO, H 2 O and n-butane-free air was used to remove NO 2 , CO 2 , CO, H 2 O and n-butane-free air. The gas concentration was measured by a flow method in which air containing butane was used. FIG. 6 is a graph showing curves 25 and 26 representing the frequency difference A and the frequency difference B, respectively. According to this figure, the frequency differences A and B are shown in FIG.
Curves similar to (b) and FIG. 4 (b) are obtained. Therefore, NO 2 gas and n-butane (hydrocarbon)
As for the above, it can be seen that the concentration of a plurality of gas species can be simultaneously measured with high selectivity and high sensitivity by using only one gas sensor.
Claims (2)
吸着特性を示す選択的吸着性有機膜を担持した圧電素子
と、ガスを非選択的に吸着する非選択的吸着性有機膜を
担持した圧電素子と、これら両圧電素子に音響信号を与
える音響制御手段と、上記両圧電素子の発振周波数の差
を検出する周波数差検出手段を有する圧電素子を用いた
ガスセンサ。1. A piezoelectric element carrying a selective adsorptive organic film exhibiting a higher adsorption property for a specific gas than other gases, and a non-selective adsorptive organic film for non-selectively adsorbing a gas. A gas sensor using a piezoelectric element having a carried piezoelectric element, an acoustic control means for giving an acoustic signal to both piezoelectric elements, and a frequency difference detection means for detecting a difference in oscillation frequency of the both piezoelectric elements.
吸着特性を示す選択的吸着性有機膜を担持した圧電素子
の発振周波数を測定する工程と、ガスを非選択的に吸着
する非選択的吸着性有機膜を担持した圧電素子の発振周
波数を測定する工程と、上記両工程で測定された発振周
波数の差を求める工程を含む、圧電素子を用いたガスセ
ンサを使用するガス濃度測定方法。2. A step of measuring an oscillation frequency of a piezoelectric element carrying a selectively adsorbing organic film which exhibits a higher adsorption characteristic for a specific gas than other gases, and a non-selective adsorption of the gas. Gas concentration measuring method using a gas sensor using a piezoelectric element, including a step of measuring an oscillation frequency of a piezoelectric element carrying a selectively adsorbing organic film, and a step of obtaining a difference between the oscillation frequencies measured in the both steps. ..
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13966792A JPH05312709A (en) | 1992-05-06 | 1992-05-06 | Gas sensor using piezoelectric element and measuring method of concentration of gas using the gas sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13966792A JPH05312709A (en) | 1992-05-06 | 1992-05-06 | Gas sensor using piezoelectric element and measuring method of concentration of gas using the gas sensor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH05312709A true JPH05312709A (en) | 1993-11-22 |
Family
ID=15250618
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP13966792A Pending JPH05312709A (en) | 1992-05-06 | 1992-05-06 | Gas sensor using piezoelectric element and measuring method of concentration of gas using the gas sensor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH05312709A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2004506872A (en) * | 1999-11-03 | 2004-03-04 | インターナショナル・ビジネス・マシーンズ・コーポレーション | Cantilever sensors and transducers |
| US8508738B2 (en) | 2008-11-26 | 2013-08-13 | Panasonic Corporation | Nitrogen oxide sensing element, nitrogen oxide sensor, nitrogen oxide concentration determination device using same, and method for determining nitrogen oxide concentration |
| JP2015040793A (en) * | 2013-08-22 | 2015-03-02 | オリンパス株式会社 | Gas sensor |
| CN114323407A (en) * | 2021-12-28 | 2022-04-12 | 电子科技大学 | Flexible film type self-driven multifunctional sensor and preparation method thereof |
-
1992
- 1992-05-06 JP JP13966792A patent/JPH05312709A/en active Pending
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2004506872A (en) * | 1999-11-03 | 2004-03-04 | インターナショナル・ビジネス・マシーンズ・コーポレーション | Cantilever sensors and transducers |
| JP4992000B2 (en) * | 1999-11-03 | 2012-08-08 | インターナショナル・ビジネス・マシーンズ・コーポレーション | Sensor system and method for detecting target oligonucleotide strands |
| US8508738B2 (en) | 2008-11-26 | 2013-08-13 | Panasonic Corporation | Nitrogen oxide sensing element, nitrogen oxide sensor, nitrogen oxide concentration determination device using same, and method for determining nitrogen oxide concentration |
| JP5339305B2 (en) * | 2008-11-26 | 2013-11-13 | パナソニック株式会社 | Nitrogen oxide detection element |
| JP2015040793A (en) * | 2013-08-22 | 2015-03-02 | オリンパス株式会社 | Gas sensor |
| CN114323407A (en) * | 2021-12-28 | 2022-04-12 | 电子科技大学 | Flexible film type self-driven multifunctional sensor and preparation method thereof |
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