JPS60227160A - Carbon monoxide detecting element - Google Patents
Carbon monoxide detecting elementInfo
- Publication number
- JPS60227160A JPS60227160A JP8200384A JP8200384A JPS60227160A JP S60227160 A JPS60227160 A JP S60227160A JP 8200384 A JP8200384 A JP 8200384A JP 8200384 A JP8200384 A JP 8200384A JP S60227160 A JPS60227160 A JP S60227160A
- Authority
- JP
- Japan
- Prior art keywords
- sensitivity
- sensor
- nox
- gas
- gas sensor
- 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.)
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Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/02—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance
- G01N27/04—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance
- G01N27/12—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance of a solid body in dependence upon absorption of a fluid; of a solid body in dependence upon reaction with a fluid, for detecting components in the fluid
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- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Investigating Or Analyzing Materials By The Use Of Fluid Adsorption Or Reactions (AREA)
Abstract
Description
【発明の詳細な説明】
〔発明の概要〕
この発明は、ＮＯｘが存在しても一酸化炭素の検知感度
が低下しないようにした一酸化炭素検知素子に関するも
のである。”
〔従来技術〕
一酸化炭素（ＣＯ）選択性のガス検知素子（以下ガスセ
ンサという）は、工業用としては早くから広く使用され
てきた。最近、一般家庭において瞬間湯沸器、ガススト
ーブ、石油ストーブ等の燃焼器具の室内での長時間使用
に伴うＣＯガス中毒が大きな社会問題としてクローズア
ップされ、中毒防止用の種々の装置が要求されるように
なってきた。中でも信頼性の高いＣＯ選択性のガスセン
サの開発は重要な課題になっていた。DETAILED DESCRIPTION OF THE INVENTION [Summary of the Invention] The present invention relates to a carbon monoxide detection element whose carbon monoxide detection sensitivity does not decrease even in the presence of NOx. ” [Prior Art] Carbon monoxide (CO) selective gas detection elements (hereinafter referred to as gas sensors) have been widely used in industrial applications since early on. CO gas poisoning caused by long-term indoor use of combustion appliances such as The development of gas sensors has become an important issue.
これまで、家庭用のＣＯ選択性のガスセンサとして５ｎ
０２等の金属酸化物半導体を主体としたガスセンサが開
発されてきたが、これには大きな欠点があった。すなわ
ち、微量（例えば５０ｐｐｍ）のＮＯＸ （主にＮＯと
Ｎ０２）が共存すると、そのＣＯ感度が低下するという
ことである。これは、測定結果によれば、上記燃焼器具
からの燃焼排ガス中にはＮＯＸが含まれ、例えばＣＯ中
毒の危険を招くような最悪の状態では室内中に最大５０
ｐｐｍ程度のＮＯＸが存在するようになると考えられる
。このような微量のＮＯＸ共存下でも、従来のガスセン
サにおいてはそのＣＯ感度に対する影響は大きく、ＣＯ
の真の濃度より低い濃度を指示したり、あるいは警報器
にあってはｃｏの警報設定濃度より高い濃度でないと警
報を発しないという重大な事態になる。これを避けるた
め活性炭等の吸着剤でガスセンサを覆い、ＮＯＸを選択
的に除去し、ガスセンサに到達しないようにしている。Until now, 5n has been used as a CO-selective gas sensor for home use.
Gas sensors based on metal oxide semiconductors such as 02 have been developed, but these have major drawbacks. That is, when a trace amount (for example, 50 ppm) of NOX (mainly NO and N02) coexists, the CO sensitivity decreases. This is because, according to measurement results, the combustion exhaust gas from the above-mentioned combustion appliances contains NOX, and in the worst conditions, for example, leading to the risk of CO poisoning, up to 50 NOX can be present in the room.
It is thought that approximately ppm of NOX will be present. Even in the coexistence of such a small amount of NOX, the effect on the CO sensitivity of conventional gas sensors is large;
This could lead to a serious situation where the CO concentration is lower than the true concentration, or an alarm will not issue an alarm unless the CO concentration is higher than the alarm setting concentration. To avoid this, the gas sensor is covered with an adsorbent such as activated carbon to selectively remove NOx and prevent it from reaching the gas sensor.
ところで、５ｎ０２半導体を主体とするガスセンサにお
いては、ＣＯの対Ｒ２選択性を得るために適当な触媒（
例えばＰｄ、Ｐｔ等）をそれに担持させ、さらに低温（
約９０〜１５０°Ｃ程度）で動作させる必要′がある。By the way, in a gas sensor based on a 5n02 semiconductor, an appropriate catalyst (
For example, Pd, Pt, etc.) are supported on it, and further low temperature (
It is necessary to operate at a temperature of approximately 90 to 150°C.
しかし、このような低温状態のままでは大気中の水分等
が吸着することによる妨害により安定したＣｏ感度は得
られない。However, in such a low temperature state, stable Co sensitivity cannot be obtained due to interference caused by adsorption of moisture, etc. in the atmosphere.
このため、周期的に一定時間高い温度（例えば３５０〜
４５０°Ｃ）で吸着水等の妨害物質を除去（パージ）す
ることによって安定したＣｏ感度を得ている。このよう
な低温で働かせるガスセンサにおいて、従来では、ＮＯ
ｘはＣＯの場合とは反対の方向にガスセンサ出力を変化
させる。すなわち、ＣＯは半導体上での諸反応の結果と
して半導体中の電導電子を増加させるのに対して、ＮＯ
ｘは５ｎ０２半導体表面に吸着する際、半導体中の電導
電子を捕獲して負イオンになる。これによってＮＯｘは
半導体の抵抗値を大きくする方向に作用する。ＮＯｘの
このような特性は、ＮＯｘ共存下でＣｏ感度を低下させ
る原因となる。従来のガスセンサのＮＯＸに対するこの
ような特性はＣＯ中毒防止の見地から大きな欠点であっ
た。For this reason, the temperature is periodically high for a certain period of time (for example, 350~
Stable Co sensitivity is obtained by removing (purging) interfering substances such as adsorbed water at a temperature of 450°C. Conventionally, in gas sensors that operate at such low temperatures, NO
x changes the gas sensor output in the opposite direction to that for CO. That is, CO increases the number of conduction electrons in the semiconductor as a result of various reactions on the semiconductor, whereas NO
When x adsorbs to the surface of the 5n02 semiconductor, it captures conduction electrons in the semiconductor and becomes negative ions. This causes NOx to act in a direction that increases the resistance value of the semiconductor. Such characteristics of NOx cause a decrease in Co sensitivity in the coexistence of NOx. Such characteristics of conventional gas sensors with respect to NOX were a major drawback from the viewpoint of preventing CO poisoning.
この発明は、上記の欠点を解消するためになされたもの
で、５ｎ０２半導体の焼結体に酸化ルテニウムを、その
熱的安定性を得るためにチタン（Ｔｉ）、ジルコニウム
（Ｚｒ）、ハフニウム（Ｈｆ）、セリウム（Ｃｅ）、ラ
ンタン（Ｌａ）などの金属酸化物とともに担持させ、Ｃ
ｏ感度および選択性の経時的変化を最小限に抑えるとと
もに、ＮＯｘの存在によってＣｏ感度の低下がないよう
にした一酸化炭素検知素子を提供するものである。以下
この発明について説明する。This invention was made to eliminate the above-mentioned drawbacks, and in order to obtain thermal stability, ruthenium oxide was added to the sintered body of the 5n02 semiconductor, and titanium (Ti), zirconium (Zr), and hafnium (Hf) were added to the sintered body of the 5n02 semiconductor. ), cerium (Ce), lanthanum (La), etc., and C
The present invention provides a carbon monoxide sensing element that minimizes temporal changes in o sensitivity and selectivity and prevents decrease in cobalt sensitivity due to the presence of NOx. This invention will be explained below.
この発明の一酸化炭素検知素子（以下ＣＯガスセンサと
いう）は白金・ロジウム線（線径２０ｇｍ）をコイル（
コイル径０．２ｍｍで１０コイル）にして、そのコイル
部分に５ｎＯ７半導体を球状（直径約０．６ｍｍ）に焼
結させ、さらに、酸化ルテニウムとトリウムの酸化物（
ドリア）を担持した。このようにして形成されたＣＯガ
スセンサは、第１図に示すように、周知のブリッジ回路
に組み込まれる。この図において、Ｒｓはこの発明のＣ
Ｏガスセンサ、Ｒｏ、Ｒ，、Ｒ２は抵抗器、Ｅは電源、
■は電圧計である。ＣＯガスセンサＲｓの抵抗変化に伴
い、回路の電位差が変化するが、この電位差を電圧計Ｖ
で測定し、その読みをＣＯガスセンサＲｓの出力とする
。電源Ｅは第２図（ｂ）に示すように、一定の周期で測
定電圧Ｅ８とパージ電圧Ｅｐとに交互に変動させ、これ
に応じた００ガスセンサＲｓの出力は第２図（ａ）のよ
うに変化する。第２図（ａ）において、Ｖａは前記ＣＯ
ガスセンサＲｓの空気中の出力、Ｖｇは同じく検知ガス
と共存したときの出力である。また、１．はガス注入の
時刻、ｔ２はガス開放の時刻であり、Ｏ印はＣｏガスセ
ンサＲｓの測定点を示し、この発明においては、ガス感
度＝Ｖｇ −Ｖａ
として定義する。The carbon monoxide detection element of this invention (hereinafter referred to as CO gas sensor) is a coil made of platinum/rhodium wire (wire diameter 20gm).
10 coils with a coil diameter of 0.2 mm), 5nO7 semiconductor was sintered into a spherical shape (about 0.6 mm in diameter) in the coil part, and ruthenium oxide and thorium oxide (
Doria). The CO gas sensor thus formed is incorporated into a well-known bridge circuit, as shown in FIG. In this figure, Rs is C of this invention.
O gas sensor, Ro, R,, R2 are resistors, E is power supply,
■ is a voltmeter. As the resistance of the CO gas sensor Rs changes, the potential difference in the circuit changes.
The reading is taken as the output of the CO gas sensor Rs. As shown in Fig. 2(b), the power supply E alternately changes the measurement voltage E8 and the purge voltage Ep at a constant cycle, and the corresponding output of the 00 gas sensor Rs is as shown in Fig. 2(a). Changes to In FIG. 2(a), Va is the CO
The output of the gas sensor Rs in the air, Vg, is also the output when it coexists with the detection gas. Also, 1. is the time of gas injection, t2 is the time of gas release, and the O mark indicates the measurement point of the Co gas sensor Rs, which is defined as gas sensitivity=Vg - Va in this invention.
第３図は燃焼器具を使用した場合の測定結果に従ってＣ
ｏ感度に対する代表的な干渉ガスとしてのＲ２とＮＯの
影響を示したものである。この図において、曲線■はＣ
Ｏガスのみの場合の感度を示し、曲線■はＣＯ：Ｈ２＝
２：１の場合の感度を示し、また、曲線■はＮｏ（５０
ｐｐｍ）とｃ。Figure 3 shows C according to the measurement results when using a combustion appliance.
This figure shows the influence of R2 and NO as typical interfering gases on o sensitivity. In this figure, the curve ■ is C
The sensitivity in the case of O gas only is shown, and the curve ■ is CO:H2=
The sensitivity in the case of 2:1 is shown, and the curve ■ is No (50
ppm) and c.
：Ｈ２＝２：１（この濃度比は実際の燃焼排ガス中の代
表例である）の雰囲気の場合の感度を示している。この
結果、この発明のＣＯガスセンサＲｓにおいては、Ｎｏ
（５０ＰＰＩｌ＋）はＣｏ感度を見かけ上、少し高い方
向に変化させるのみであり、Ｎｏが存在していても感度
の変化がほとんどないことがわかる。しかも感度は高い
方に移動するため、フェイルセーフとなり、この点から
も特性が改善されたといえる。:H2=2:1 (this concentration ratio is a typical example in actual combustion exhaust gas). As a result, in the CO gas sensor Rs of this invention, No.
It can be seen that (50PPIl+) only apparently changes the Co sensitivity in a slightly higher direction, and there is almost no change in sensitivity even if No is present. Moreover, since the sensitivity is shifted to the higher side, it becomes a fail-safe, and from this point of view as well, it can be said that the characteristics have been improved.
なお、上記実施例では、金属酸化物半導体の焼結体に酸
化ルテニウムとトリウムの酸化物を担持させた場合を示
したが、この発明は、トリウムの酸化物に代えてチタン
、ジルコニウム、ハフニウム、セリウム、ランタンのい
ずれか１種または２種以上の金属酸化物を用いても同様
の結果が得られる。In addition, in the above example, a case was shown in which oxides of ruthenium oxide and thorium were supported on a sintered body of a metal oxide semiconductor, but in this invention, instead of oxide of thorium, titanium, zirconium, hafnium, Similar results can be obtained by using one or more metal oxides of cerium and lanthanum.
例えば、上記実施例と同一の手法で酸化ルテニウム、ド
リアおよび酸化ランタンを担持して得られたＣＯガスセ
ンサは対水素選択性に関して前記実施例（第３図）に比
較し僅かに改善された。一方、ＮＯＸの影響については
同程度であった。For example, a CO gas sensor obtained by supporting ruthenium oxide, doria, and lanthanum oxide using the same method as in the above example showed a slight improvement in hydrogen selectivity compared to the above example (FIG. 3). On the other hand, the effects of NOX were at the same level.
なお、金属酸化物半導体として５ｎ０２を用いた場合を
示したが、この発明はこれに限らすＺｎＯ，Ｆｅ２Ｏ３
等の他のものを使用することもできる。Although the case where 5n02 is used as the metal oxide semiconductor is shown, this invention is not limited to this.
Others can also be used, such as.
また、上記の実施例では、白金、ロジウム合金線からな
るコイルを電極とヒータに用いた例を示したが、この発
明はこれに限定されるものでないことは明らかなことで
ある。また、ルテニウムとトリウムの混合比も上記実施
例に限定されない。Further, in the above embodiment, an example was shown in which coils made of platinum and rhodium alloy wire were used for the electrodes and the heater, but it is clear that the present invention is not limited to this. Further, the mixing ratio of ruthenium and thorium is not limited to the above embodiment.
なお、ＮＯｘも人体に有毒なガスであるので（Ｎｏ（７
）許容濃度は２５ｐｐｍであり、Ｎｏ２のそｈ ハ３
ｐｐｍである）、この発明のＣＯガスセンサは、このよ
うなＮＯｘが単独に存在してもある濃度に達すれば、例
えば警報を出させることも可能である。この特性は安全
性の面から見てさらに一歩改善されている。Note that NOx is also a gas that is toxic to the human body (No (7)
) The permissible concentration is 25 ppm, No. 2, No. 3.
ppm), and the CO gas sensor of the present invention can issue an alarm, for example, if such NOx exists alone and reaches a certain concentration. This property has been improved one step further from a safety perspective.
以上説明したようにこの発明は、金属酸化物半導体の焼
結体に酸化ルテニウムとチタン、ジルコニウム、ハフニ
ウム、トリウム、セリウム、ランタンのいずれか１種ま
たは２種以上の金属酸化物を担持させてＣＯガスセンサ
としたのでＮＯｘの存在によってもＣＯガスに対する感
度がほとんど変動しなくなり信頼性の高いＣＯガスセン
サが得られる。As explained above, the present invention allows a sintered body of a metal oxide semiconductor to support ruthenium oxide and one or more metal oxides of titanium, zirconium, hafnium, thorium, cerium, and lanthanum, thereby producing CO2. Since it is a gas sensor, the sensitivity to CO gas hardly changes even in the presence of NOx, and a highly reliable CO gas sensor can be obtained.
また、酸化ルテニウムは本来熱的に不安定であるが、こ
れにチタン、ジルコニウム、ハフニウム、セリウム、ラ
ンタンのいずれか１種の金属酸化物を共存させると、酸
化ルテニウムの触媒作用を安定化させることができ、Ｃ
Ｏ感度の経時安定性を得ることができる。また、同時に
、ＣＯの対Ｈ２選択性も高めることができる利点かある
。Furthermore, although ruthenium oxide is inherently thermally unstable, when one of the metal oxides of titanium, zirconium, hafnium, cerium, and lanthanum coexists with it, the catalytic action of ruthenium oxide can be stabilized. is completed, C
It is possible to obtain stability of O sensitivity over time. At the same time, it also has the advantage of increasing the selectivity of CO to H2.
第１図はこの発明の′ＣＯガスセンサを使用した検知装
置の回路図、第２図（ａ）、（ｂ）は第１図の動作を説
明する波形図、第３図は第１図の検知装置による測定結
果の一例を示す特性図である。
図中、ＲｓはＣＯガスセンサ、Ｒｏ、Ｒ，、。
Ｒ２は抵抗器、Ｅは電ｍ、■は電圧計、Ｒ８は′Ａ１１
１定電圧、Ｅ’ｐはパージ電圧、Ｖａは通常大気中での
ＣＯガスセンサ出力、Ｖ、ｇは検知ガスと共存したとき
のＣＯガスセンサ出力である。
第１図
第２図Figure 1 is a circuit diagram of a detection device using the CO gas sensor of the present invention, Figures 2 (a) and (b) are waveform diagrams explaining the operation of Figure 1, and Figure 3 is the detection of Figure 1. FIG. 3 is a characteristic diagram showing an example of measurement results obtained by the device. In the figure, Rs is a CO gas sensor, Ro, R, . R2 is a resistor, E is electric m, ■ is a voltmeter, R8 is 'A11
1 constant voltage, E'p is the purge voltage, Va is the CO gas sensor output in normal atmosphere, and V and g are the CO gas sensor outputs when coexisting with the detection gas. Figure 1 Figure 2
Claims (1)
、ジルコニウム、ハフニウム、トリウム、セリウム、ラ
ンタンのいずれか１種または２種以上の金属酸化物との
混合物を相持させたことを特徴とする一酸化炭素検知素
子。A product characterized in that a sintered body of a metal oxide semiconductor is combined with a mixture of ruthenium oxide and one or more metal oxides of titanium, zirconium, hafnium, thorium, cerium, and lanthanum. Carbon oxide detection element.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8200384A JPS60227160A (en) | 1984-04-25 | 1984-04-25 | Carbon monoxide detecting element |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8200384A JPS60227160A (en) | 1984-04-25 | 1984-04-25 | Carbon monoxide detecting element |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS60227160A true JPS60227160A (en) | 1985-11-12 |
| JPH0514860B2 JPH0514860B2 (en) | 1993-02-26 |
Family
ID=13762335
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP8200384A Granted JPS60227160A (en) | 1984-04-25 | 1984-04-25 | Carbon monoxide detecting element |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS60227160A (en) |
Citations (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5432395A (en) * | 1977-08-17 | 1979-03-09 | Toshiba Corp | Gas sensitive element |
| JPS5439197A (en) * | 1977-09-02 | 1979-03-26 | Shibaura Denshi Seisakushiyo K | Method of making gas detector |
| JPS5698646A (en) * | 1980-01-09 | 1981-08-08 | Matsushita Electric Works Ltd | Flamable-gas detecting element |
| JPS56109866A (en) * | 1980-01-29 | 1981-08-31 | Nippon Electric Co | Carbon monoxide gas sensor element and its manufacture |
| JPS56114751A (en) * | 1980-02-15 | 1981-09-09 | Matsushita Electric Works Ltd | Detecting element for combustible gas |
| JPS56118660A (en) * | 1980-02-23 | 1981-09-17 | Matsushita Electric Works Ltd | Combustible gas detecting element |
| JPS56164947A (en) * | 1980-05-24 | 1981-12-18 | Matsushita Electric Works Ltd | Inflammable gas detecting element |
| JPS5873853A (en) * | 1981-10-28 | 1983-05-04 | Hitachi Ltd | Gas sensor composition |
| JPS58168952A (en) * | 1982-03-30 | 1983-10-05 | Mitsubishi Electric Corp | Gas sensitive element |
| JPS58180940A (en) * | 1982-04-17 | 1983-10-22 | Fuigaro Giken Kk | Addition of reaction promotor to combustion state detecting element |
| JPS58180939A (en) * | 1982-04-17 | 1983-10-22 | Fuigaro Giken Kk | Element for detecting combustion state |
| JPS5957154A (en) * | 1982-09-27 | 1984-04-02 | Matsushita Electric Ind Co Ltd | Gas detecting element |
| JPS60202345A (en) * | 1984-03-28 | 1985-10-12 | Hitachi Ltd | Gas detecting element |
-
1984
- 1984-04-25 JP JP8200384A patent/JPS60227160A/en active Granted
Patent Citations (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5432395A (en) * | 1977-08-17 | 1979-03-09 | Toshiba Corp | Gas sensitive element |
| JPS5439197A (en) * | 1977-09-02 | 1979-03-26 | Shibaura Denshi Seisakushiyo K | Method of making gas detector |
| JPS5698646A (en) * | 1980-01-09 | 1981-08-08 | Matsushita Electric Works Ltd | Flamable-gas detecting element |
| JPS56109866A (en) * | 1980-01-29 | 1981-08-31 | Nippon Electric Co | Carbon monoxide gas sensor element and its manufacture |
| JPS56114751A (en) * | 1980-02-15 | 1981-09-09 | Matsushita Electric Works Ltd | Detecting element for combustible gas |
| JPS56118660A (en) * | 1980-02-23 | 1981-09-17 | Matsushita Electric Works Ltd | Combustible gas detecting element |
| JPS56164947A (en) * | 1980-05-24 | 1981-12-18 | Matsushita Electric Works Ltd | Inflammable gas detecting element |
| JPS5873853A (en) * | 1981-10-28 | 1983-05-04 | Hitachi Ltd | Gas sensor composition |
| JPS58168952A (en) * | 1982-03-30 | 1983-10-05 | Mitsubishi Electric Corp | Gas sensitive element |
| JPS58180940A (en) * | 1982-04-17 | 1983-10-22 | Fuigaro Giken Kk | Addition of reaction promotor to combustion state detecting element |
| JPS58180939A (en) * | 1982-04-17 | 1983-10-22 | Fuigaro Giken Kk | Element for detecting combustion state |
| JPS5957154A (en) * | 1982-09-27 | 1984-04-02 | Matsushita Electric Ind Co Ltd | Gas detecting element |
| JPS60202345A (en) * | 1984-03-28 | 1985-10-12 | Hitachi Ltd | Gas detecting element |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0514860B2 (en) | 1993-02-26 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EXPY | Cancellation because of completion of term |