JP2003149191A - Gas sensor - Google Patents

Gas sensor

Info

Publication number
JP2003149191A
JP2003149191A JP2001344781A JP2001344781A JP2003149191A JP 2003149191 A JP2003149191 A JP 2003149191A JP 2001344781 A JP2001344781 A JP 2001344781A JP 2001344781 A JP2001344781 A JP 2001344781A JP 2003149191 A JP2003149191 A JP 2003149191A
Authority
JP
Japan
Prior art keywords
electrode
gas sensor
gas
area
hydrogen gas
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
Application number
JP2001344781A
Other languages
Japanese (ja)
Inventor
Tomonori Kondo
智紀 近藤
Shoji Kitanoya
昇治 北野谷
Norihiko Nadanami
紀彦 灘浪
Masaya Watanabe
昌哉 渡辺
Noboru Ishida
昇 石田
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Niterra Co Ltd
Original Assignee
NGK Spark Plug Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by NGK Spark Plug Co Ltd filed Critical NGK Spark Plug Co Ltd
Priority to JP2001344781A priority Critical patent/JP2003149191A/en
Priority to CA002400882A priority patent/CA2400882A1/en
Priority to US10/231,209 priority patent/US20030042139A1/en
Priority to EP02256064A priority patent/EP1288655A3/en
Publication of JP2003149191A publication Critical patent/JP2003149191A/en
Pending legal-status Critical Current

Links

Classifications

    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/30—Hydrogen technology
    • Y02E60/50—Fuel cells

Abstract

PROBLEM TO BE SOLVED: To provide a gas sensor capable of accurately measuring gas concentration such as the concentration of hydrogen gas. SOLUTION: The ratio (area ratio) S1/S2 of a first area S1 (a mesh part of Figure 1) of a first electrode 3 existing outside of a projected part in the case of projecting a second electrode 5 on the first electrode 3, to a second area S2 (an oblique line part of Figure 2) overlapped with the first electrode 3 in the case of projecting the second electrode on the first electrode 3, is set to be less than 0.35. That is, the first electrode 3 and the second electrode 5 are arranged and dimensioned so that the second electrode 5 is within the first electrode 3 in the case of projecting the second electrode 5 on the first electrode 3, and the area ratio S1/S2 is set to be less than 0.35.

Description

【発明の詳細な説明】Detailed Description of the Invention

【０００１】[0001]

【発明の属する技術分野】本発明は、例えば燃料電池の
燃料ガス中の水素ガス濃度を測定する水素ガスセンサ等
のガスセンサに関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas sensor such as a hydrogen gas sensor for measuring the hydrogen gas concentration in the fuel gas of a fuel cell.

【０００２】[0002]

【従来の技術】近年、地球規模の環境悪化が問題視され
るなかで、高効率でクリーンな動力源として、燃料電池
の研究が盛んに行われている。その中で、低温作動、高
出力密度等の利点により、自動車用や家庭用として固体
高分子型燃料電池（ＰＥＦＣ）が期待されている。2. Description of the Related Art In recent years, fuel cells have been extensively researched as a highly efficient and clean power source amid environmental problems on a global scale. Among them, a polymer electrolyte fuel cell (PEFC) is expected for automobiles and households due to advantages such as low temperature operation and high power density.

【０００３】この燃料電池の場合、燃料ガスとして、改
質ガスの使用が有望であるが、より効率等を向上させる
為に、改質ガス中の水素を直接検知できるセンサが必要
になってくる。上記センサは、水素リッチの雰囲気での
測定になる為、作動温度が低いこと（約１００℃以下）
が必要である。In the case of this fuel cell, it is promising to use a reformed gas as the fuel gas, but in order to improve efficiency and the like, a sensor which can directly detect hydrogen in the reformed gas is required. . The above sensor has a low operating temperature (less than about 100 ° C) because it is measured in a hydrogen-rich atmosphere.
is necessary.

【０００４】このような低温作動型センサとして、例え
ばＥＰ１１０３８０７Ａ２号の公報では、図６に示す様
に、高分子電解質からなるプロトン伝導層１０１を用い
るとともに、プロトン伝導層１０１の表面に、第１電極
１０２、第２電極１０３及び参照電極１０４を設置した
構造のセンサが提案されている。As such a low temperature operation type sensor, for example, in the publication of EP1103807A2, as shown in FIG. 6, a proton conductive layer 101 made of a polymer electrolyte is used, and the first electrode is formed on the surface of the proton conductive layer 101. A sensor having a structure in which the 102, the second electrode 103, and the reference electrode 104 are installed is proposed.

【０００５】[0005]

【発明が解決しようとする課題】しかし、上述したセン
サでは、プロトン伝導層１０１を挟んで第２電極１０３
を投影した部分以外にも第１電極１０２が配設されてい
るため、即ち、第１電極１０２は、第２電極１０３だけ
でなくそれ以外の参照電極１０４にも対向して配置され
ているため、第１電極１０２から第２電極１０３に水素
（詳しくは水素イオンであるプロトン：Ｈ+）をポンピ
ングする際に、水素がポンピングされ難い部分（即ち水
素濃度が高い部分：図６のメッシュの部分）が存在す
る。However, in the above-mentioned sensor, the second electrode 103 is sandwiched with the proton conducting layer 101 interposed therebetween.
Since the first electrode 102 is arranged in a portion other than the portion where is projected, that is, the first electrode 102 is arranged not only in the second electrode 103 but also in the other reference electrode 104. When pumping hydrogen (specifically, protons: H + which are hydrogen ions) from the first electrode 102 to the second electrode 103, a portion where hydrogen is difficult to be pumped (that is, a portion having a high hydrogen concentration: a portion of the mesh in FIG. 6) ) Exists.

【０００６】しかも、このセンサでは、第１電極１０２
と参照電極１０４を一定の電位に制御しているが、その
場合には、制御電位は、第１電極１０２上の平均的な水
素濃度と参照電極１０４上での水素濃度によって規定さ
れる。従って、このセンサのように、水素がポンピング
され難い部分が存在すると、その部分の水素濃度が高い
状態となってしまうため、平均的な水素濃度を低く制御
しようとすると、通常より多くのポンピングが実施され
て、第１電極１０２上にて局所的に非常に水素濃度が低
い部分が存在してしまう。Moreover, in this sensor, the first electrode 102
And the reference electrode 104 is controlled to a constant potential. In that case, the control potential is defined by the average hydrogen concentration on the first electrode 102 and the hydrogen concentration on the reference electrode 104. Therefore, if there is a portion where hydrogen is difficult to be pumped, such as this sensor, the hydrogen concentration in that portion will be high, so if you try to control the average hydrogen concentration to a low level, more pumping than usual will occur. After being carried out, a portion having a very low hydrogen concentration locally exists on the first electrode 102.

【０００７】その結果、水素濃度が局所的に低い部分で
は、メタノール等の解離等が起こることがあるため、第
１電極１０２と第２電極１０３との間に流れる電流値が
大きくなり、水素ガス濃度測定に影響を及ぼし、正確な
水素濃度の測定が出来ないという問題が生じる。As a result, in a portion where the hydrogen concentration is locally low, dissociation of methanol or the like may occur, so that the current value flowing between the first electrode 102 and the second electrode 103 becomes large and the hydrogen gas This affects the concentration measurement and causes a problem that the hydrogen concentration cannot be measured accurately.

【０００８】本発明は、前記課題を解決するためになさ
れたものであり、正確に例えば水素ガス濃度等のガス濃
度を測定することができるガスセンサを提供することを
目的とする。The present invention has been made to solve the above problems, and an object thereof is to provide a gas sensor capable of accurately measuring a gas concentration such as a hydrogen gas concentration.

【０００９】[0009]

【課題を解決するための手段及び発明の効果】（１）請
求項１の発明は、プロトン伝導層に接して設けられた第
１電極、第２電極及び参照電極と、被測定ガス雰囲気及
び第１電極との間に設けられた拡散律速部と、を有し、
被測定ガス雰囲気側から拡散律速部を介して導入された
被測定ガス中の測定対象ガス（例えば水素ガス）を、第
１電極と参照電極との間の電位差が一定になるように、
第１電極と第２電極との間に（限界電流を得るための十
分な）電圧を印加することにより解離又は分解もしくは
反応させ、それによって発生したプロトンをプロトン伝
導層を介して第１電極側から第２電極側へ汲み出すこと
により生じる限界電流に基づいて、測定対象ガスの濃度
を求めるガスセンサに関するものである。Means for Solving the Problems and Effects of the Invention (1) According to the invention of claim 1, the first electrode, the second electrode and the reference electrode provided in contact with the proton conductive layer, the gas atmosphere to be measured and the first electrode A diffusion rate-controlling part provided between one electrode and
The measurement target gas (for example, hydrogen gas) in the measurement target gas introduced from the measurement target gas atmosphere side through the diffusion rate controlling portion is controlled so that the potential difference between the first electrode and the reference electrode becomes constant.
A voltage (sufficient for obtaining a limiting current) is applied between the first electrode and the second electrode to cause dissociation or decomposition or reaction, and protons generated thereby are passed through the proton conduction layer to the first electrode side. The present invention relates to a gas sensor that obtains the concentration of a gas to be measured based on a limiting current generated by pumping the gas to the second electrode side.

【００１０】特に本発明では、第１電極と第２電極とが
プロトン伝導層を挟んで対向する構造を有するととも
に、第２電極を第１電極に投影した場合に当該投影した
部分以外に存在する第１電極の第１面積Ｓ１と、第２電
極を前記第１電極に投影した場合に当該第１電極と重な
る第２電極の第２面積Ｓ２との比Ｓ１／Ｓ２を、０．３
５未満としたことを特徴としている。Particularly in the present invention, the first electrode and the second electrode have a structure in which they are opposed to each other with the proton conducting layer interposed therebetween, and when the second electrode is projected on the first electrode, it exists in a portion other than the projected portion. The ratio S1 / S2 between the first area S1 of the first electrode and the second area S2 of the second electrode that overlaps the first electrode when the second electrode is projected onto the first electrode is 0.3.
It is characterized in that it is less than 5.

【００１１】つまり、本発明では、第１電極の第１面積
Ｓ１と第２電極の第２面積Ｓ２との比Ｓ１／Ｓ２を、
０．３５未満としたので、即ち、第１電極と第２電極と
は、その投影方向にて多くの部分が重なり合っているの
で、上述したポンピングされにくい部分の影響が小さく
なる。その結果、第１電極と参照電極との間を一定の電
位差に制御する際に、水素等の濃度が局所的に低い部分
が発生しない。これによって、メタノール等の解離等が
起こることを防止できるため、メタノール等による影響
を受けず、正確に水素等の測定対象ガスの濃度を測定す
ることが可能となる。That is, in the present invention, the ratio S1 / S2 of the first area S1 of the first electrode and the second area S2 of the second electrode is given by:
Since it is less than 0.35, that is, since the first electrode and the second electrode overlap in many parts in the projection direction, the influence of the above-mentioned part that is difficult to pump is small. As a result, when the potential difference between the first electrode and the reference electrode is controlled to a constant value, a portion where the concentration of hydrogen or the like is locally low does not occur. As a result, dissociation of methanol or the like can be prevented, so that the concentration of the gas to be measured such as hydrogen can be accurately measured without being affected by methanol or the like.

【００１２】（２）請求項２の発明は、前記第２電極を
前記第１電極に投影した場合に、前記第１電極及び前記
第２電極のうち、面積の小さい方の電極が大きい方の電
極の投影領域内にあるように、前記第１電極及び前記第
２電極を設けたことを特徴としている。(2) According to a second aspect of the invention, when the second electrode is projected onto the first electrode, one of the first electrode and the second electrode having a smaller area has a larger area. It is characterized in that the first electrode and the second electrode are provided so as to be in the projection area of the electrode.

【００１３】本発明は、第１電極と第２電極との位置及
び大きさの関係を規定したものであり、本発明の場合に
は、第１電極及び第２電極のうち、面積の小さい方の電
極の全ての部位が面積の大きいほうの電極と対向してい
るので、第１電極側から第２電極側への例えば水素等の
測定対象物質のポンピングを効率よく行うことができ
る。The present invention defines the relationship between the position and the size of the first electrode and the second electrode. In the case of the present invention, one of the first electrode and the second electrode having the smaller area is used. Since all the parts of the electrode face the electrode having the larger area, it is possible to efficiently pump the substance to be measured such as hydrogen from the first electrode side to the second electrode side.

【００１４】（３）請求項３の発明は、ガスセンサは、
水素ガス濃度を測定する水素ガスセンサであることを特
徴としている。本発明は、ガスセンサが、水素ガス濃度
を測定する水素ガスセンサであることを例示したもので
ある。(3) In the invention of claim 3, the gas sensor is
It is characterized by being a hydrogen gas sensor that measures the hydrogen gas concentration. The present invention exemplifies that the gas sensor is a hydrogen gas sensor that measures hydrogen gas concentration.

【００１５】（４）請求項４の発明は、ガスセンサは、
固体高分子型燃料電池の燃料ガス中の水素ガス濃度測定
に用いられることを特徴としている。本発明は、ガスセ
ンサの用途を例示したものである。本発明により、固体
高分子型燃料電池の燃料ガス中の水素ガス濃度の測定
を、メタノール等の影響を受けずに精度良く行うことが
可能である。(4) In the invention of claim 4, the gas sensor is
It is characterized by being used for measuring the hydrogen gas concentration in the fuel gas of a polymer electrolyte fuel cell. The present invention illustrates the application of the gas sensor. According to the present invention, it is possible to accurately measure the hydrogen gas concentration in the fuel gas of a polymer electrolyte fuel cell without being affected by methanol or the like.

【００１６】尚、前記ガスセンサの構成としては、前記
プロトン伝導層、第１電極、第２電極、参照電極、及び
拡散律速部は、支持体により支持される構成を採用でき
る。また、拡散律速部としては、被測定ガス雰囲気から
拡散律速部を介してガスセンサ内に導入される被測定ガ
ス（特に測定対象ガス）の拡散を律速するものであり、
例えば支持体に開けられた貫通孔、又はその孔に充填さ
れたガス透過性の多孔体などにより実現することができ
る。As the structure of the gas sensor, the proton conducting layer, the first electrode, the second electrode, the reference electrode, and the diffusion rate controlling part may be supported by a support. Further, the diffusion rate controlling part is for controlling the diffusion of the measured gas (particularly the measurement target gas) introduced into the gas sensor from the measured gas atmosphere through the diffusion controlling part,
For example, it can be realized by a through hole formed in the support or a gas permeable porous body filled in the hole.

【００１７】[0017]

【発明の実施の形態】以下に、本発明のガスセンサの実
施の形態の例（実施例）について説明する。 （実施例１）本実施例では、ガスセンサとして、固体高
分子型燃料電池の燃料ガス中の水素ガス濃度測定に用い
られる水素ガスセンサを例に挙げる。BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an example (embodiment) of an embodiment of a gas sensor of the present invention will be described. (Example 1) In this example, a hydrogen gas sensor used for measuring the concentration of hydrogen gas in the fuel gas of a polymer electrolyte fuel cell will be described as an example of the gas sensor.

【００１８】ａ）まず、本実施例の水素ガスセンサの構
成について、図１に基づいて説明する。尚、図１は、水
素ガスセンサの長手方向の断面図である。図１に示す様
に、本実施例の水素ガスセンサは、プロトン伝導層１の
一方の面（同図の上面）に、第１電極３が設けられ、プ
ロトン伝導層１の他方の面（同図の下面）に、第１電極
３と対向するように、第２電極５及び参照電極７が設け
られ、それらは、第１支持体８及び第２支持体９からな
る支持体１０中に支持されている。A) First, the structure of the hydrogen gas sensor of this embodiment will be described with reference to FIG. Note that FIG. 1 is a longitudinal sectional view of the hydrogen gas sensor. As shown in FIG. 1, in the hydrogen gas sensor of the present embodiment, the first electrode 3 is provided on one surface (the upper surface in the same figure) of the proton conducting layer 1 and the other surface of the proton conducting layer 1 (the same figure). A second electrode 5 and a reference electrode 7 are provided so as to face the first electrode 3, and they are supported in a support 10 composed of a first support 8 and a second support 9. ing.

【００１９】つまり、プロトン伝導層１は、第１支持体
８及び第２支持体９に狭持され、第１電極３は、第１支
持体８に覆われるとともにその第１凹部１１内に配置さ
れ、第２電極５は、第２支持体９に覆われるとともにそ
の第２凹部１２内に配置され、参照電極７は、第２支持
体９に覆われるとともにその第３凹部１３内に配置され
ている。That is, the proton conducting layer 1 is sandwiched between the first support 8 and the second support 9, and the first electrode 3 is covered by the first support 8 and arranged in the first recess 11 thereof. The second electrode 5 is covered with the second support 9 and is arranged in the second recess 12, and the reference electrode 7 is covered with the second support 9 and is arranged in the third recess 13. ing.

【００２０】尚、水素ガスセンサを一体に構成する方法
としては、プロトン伝導層１を第１支持体８及び第２支
持体９により狭持した状態で、図示しない固定部材等で
固定する構成や、樹脂等により一体に固定する方法を採
用できる。前記プロトン伝導層１は、一方の面側から他
方の面側に、例えば第１電極３側から第２電極５側に、
プロトン（Ｈ+）を移動させることができるものであ
る。そのプロトン伝導層１の材料としては、比較的低温
（例えば１５０℃以下）で作動するものが良く、例えば
フッ素樹脂である「Ｎａｆｉｏｎ」（デュポン社の商
標）等を採用できる。As a method of integrally forming the hydrogen gas sensor, a structure in which the proton conductive layer 1 is sandwiched between the first support 8 and the second support 9 and fixed by a fixing member or the like (not shown), A method of integrally fixing with resin or the like can be adopted. The proton conductive layer 1 is from one surface side to the other surface side, for example, from the first electrode 3 side to the second electrode 5 side,
It is capable of moving a proton (H + ). As a material of the proton conductive layer 1, a material that operates at a relatively low temperature (for example, 150 ° C. or lower) is preferable, and for example, a fluororesin “Nafion” (trademark of DuPont) or the like can be adopted.

【００２１】前記第１電極３、第２電極５、参照電極７
は、例えばカーボンを主成分とする多孔質電極であり、
各電極３、５、７には、プロトン伝導層１に接する側に
Ｐｔ等の触媒層が塗布により形成されている。特に本実
施例では、図２に示す様に、第２電極５を第１電極３に
投影した場合に当該投影した部分以外に存在する第１電
極３の第１面積Ｓ１（同図のメッシュ部分）と、第２電
極５を第１電極３に投影した場合に当該第１電極３と重
なる第２電極５の第２面積Ｓ２（同図の斜線部分）との
比（面積比）Ｓ１／Ｓ２を、０．３５未満（例えば０．
３３以下）としている。The first electrode 3, the second electrode 5 and the reference electrode 7
Is, for example, a porous electrode containing carbon as a main component,
A catalyst layer of Pt or the like is formed on each of the electrodes 3, 5, 7 by coating on the side in contact with the proton conductive layer 1. In particular, in the present embodiment, as shown in FIG. 2, when the second electrode 5 is projected onto the first electrode 3, the first area S1 of the first electrode 3 existing other than the projected portion (the mesh portion in FIG. ) And a second area S2 of the second electrode 5 that overlaps with the first electrode 3 when the second electrode 5 is projected onto the first electrode 3 (area ratio) S1 / S2. Is less than 0.35 (eg, 0.
33 or less).

【００２２】つまり、第２電極５を第１電極３に投影し
た場合に、第２電極５が第１電極３に収容されるよう
に、第１電極３及び第２電極５の配置や大きさを設定す
るとともに、面積比Ｓ１／Ｓ２を、０．３５未満に設定
している。従って、第２電極５と第１電極３とは幅方向
の長さ及び投影方向の位置が完全に一致し、長手方向の
一端（参照電極７と反対側）も投影方向の位置が完全に
一致している。That is, when the second electrode 5 is projected onto the first electrode 3, the arrangement and size of the first electrode 3 and the second electrode 5 are set so that the second electrode 5 is housed in the first electrode 3. And the area ratio S1 / S2 is set to less than 0.35. Therefore, the second electrode 5 and the first electrode 3 have completely the same length in the width direction and the position in the projection direction, and one end in the longitudinal direction (the side opposite to the reference electrode 7) has the same position in the projection direction. I am doing it.

【００２３】また、第１電極３、第２電極５、参照電極
７は、それぞれ図示しないリード部を介して回路に接続
されており、電源（電池）１４によって、第１電極３及
び第２電極５間に電圧を印加したり、電圧計１５によっ
て、第１電極３及び参照電極７間の電圧を測定したり、
電流計１７によって、第１電極３及び第２電極５間に流
れる電流を測定できるようになっている。The first electrode 3, the second electrode 5, and the reference electrode 7 are connected to the circuit via lead portions (not shown), and the power source (battery) 14 allows the first electrode 3 and the second electrode 3 to be connected. 5 is applied, or the voltage between the first electrode 3 and the reference electrode 7 is measured by the voltmeter 15,
The ammeter 17 can measure the current flowing between the first electrode 3 and the second electrode 5.

【００２４】更に、参照電極７は、第１電極３及び参照
電極７間の電圧を一定に保つことにより、被測定ガス中
の水素ガス濃度を測定する際に、温度や湿度などの外乱
の影響を小さくするために用いられるものである。尚、
好ましくは、参照電極７での水素濃度をより安定化させ
るために、参照電極７を自己生成基準極とするのが良
い。Further, the reference electrode 7 keeps the voltage between the first electrode 3 and the reference electrode 7 constant, so that when measuring the hydrogen gas concentration in the measured gas, the influence of disturbances such as temperature and humidity is exerted. Is used to reduce still,
Preferably, the reference electrode 7 is a self-generated reference electrode in order to further stabilize the hydrogen concentration at the reference electrode 7.

【００２５】前記支持体１０は、例えばアルミナを主成
分とするセラミックスからなる絶縁体であり、セラミッ
クス等の無機絶縁体以外に、樹脂等からなる有機絶縁体
を採用できる。この支持体１０のうち、第１支持体８に
は、周囲雰囲気と第１凹部１１（従って第１電極３）と
を連通する拡散律速部１９が設けられている。The support 10 is an insulator made of, for example, ceramics containing alumina as a main component, and in addition to an inorganic insulator such as ceramics, an organic insulator made of resin or the like can be adopted. Of the support 10, the first support 8 is provided with a diffusion rate controlling portion 19 that communicates the ambient atmosphere with the first recess 11 (and thus the first electrode 3).

【００２６】つまり、拡散律速部１９は、被測定ガスで
ある燃料ガス（従って含まれる水素ガス）を第１電極３
側に導入するとともに、その拡散を律速する小さい孔
（例えば直径０．０６ｍｍの貫通孔）である。尚、拡散
律速部１９内の内径を設定したり、拡散律速部１９内に
アルミナ等の多孔質材料を充填することにより、拡散を
律速する程度を調節することができる。That is, the diffusion rate controlling portion 19 supplies the fuel gas (hence the contained hydrogen gas) as the gas to be measured to the first electrode 3
It is a small hole (for example, a through hole having a diameter of 0.06 mm) that is introduced into the side and controls the diffusion thereof. By setting the inner diameter of the diffusion control part 19 or filling the diffusion control part 19 with a porous material such as alumina, the degree of controlling the diffusion can be adjusted.

【００２７】一方、第２支持体９には、周囲雰囲気と第
２凹部１２（従って第２電極５）に連通する例えば直径
１．７ｍｍの空孔２１が設けられている。また、前記第
１支持体８及び第２支持体９は、セラミックスを含有す
るシートを積層し焼成して形成されたものであり、その
シート間に例えばＰｔ製のリード部が形成されている。
つまり、第１支持体８及び第２支持体９内には、シート
間にリード部が設けられ、このリード部が、前記各凹部
１１〜１３の底部に露出することにより、各電極３〜７
の触媒層と反対側に接触して、各電極３〜７との導通を
確保している。On the other hand, the second support 9 is provided with a hole 21 having a diameter of 1.7 mm, for example, which communicates with the ambient atmosphere and the second recess 12 (hence the second electrode 5). The first support 8 and the second support 9 are formed by laminating and firing sheets containing ceramics, and lead portions made of, for example, Pt are formed between the sheets.
That is, the lead portions are provided between the sheets in the first support 8 and the second support 9, and the lead portions are exposed at the bottoms of the recesses 11 to 13, whereby the electrodes 3 to 7 are exposed.
The electrode is in contact with the side opposite to the catalyst layer to secure conduction with the electrodes 3 to 7.

【００２８】ｂ）次に、本実施例の水素ガスセンサの測
定原理及び測定手順について説明する。水素ガスセンサ
を燃料ガスにさらすと、周囲雰囲気から拡散律速部１９
を通って第１電極３に到達した水素は、プロトン伝導層
１を介して、第１電極３と参照電極７との間に、水素ガ
スの濃度（詳しくは両電極３、７側における水素ガス濃
度の差）に応じた起電力を生じさせる。B) Next, the measurement principle and measurement procedure of the hydrogen gas sensor of this embodiment will be described. When the hydrogen gas sensor is exposed to the fuel gas, the diffusion control part
Hydrogen that has reached the first electrode 3 through the proton conductive layer 1 has a hydrogen gas concentration (specifically, hydrogen gas on both electrodes 3 and 7 side) between the first electrode 3 and the reference electrode 7. An electromotive force corresponding to the difference in concentration) is generated.

【００２９】そこで、第１電極３と参照電極７との間の
電位差が一定に成るように、電源１４により、第１電極
３と第２電極５との間に電圧を印加する。その結果、第
１電極３上で水素はプロトンに解離され、プロトンは、
プロトン伝導層１を介して第２電極５側へ汲み出され、
再び水素となって被測定ガス雰囲気に拡散する。Therefore, a voltage is applied between the first electrode 3 and the second electrode 5 by the power supply 14 so that the potential difference between the first electrode 3 and the reference electrode 7 becomes constant. As a result, hydrogen is dissociated into protons on the first electrode 3, and the protons are
It is pumped out to the second electrode 5 side through the proton conductive layer 1,
It becomes hydrogen again and diffuses into the measured gas atmosphere.

【００３０】その時、第１電極３と第２電極５との間に
流れる電流値（前記電圧を印加した場合に、ある値まで
上昇して上限となる限界電流）は、水素ガス濃度に比例
するため、その電流値を測定することにより、水素ガス
濃度の測定が可能になる。ここで、参照電極７の役割に
ついて説明する。At that time, the value of the current flowing between the first electrode 3 and the second electrode 5 (the limit current that rises to a certain value and becomes the upper limit when the voltage is applied) is proportional to the hydrogen gas concentration. Therefore, the hydrogen gas concentration can be measured by measuring the current value. Here, the role of the reference electrode 7 will be described.

【００３１】参照電極７を用いて、第１電極３と参照電
極７との間の電位差が一定に成るように印加電圧を制御
すると、第１電極３と参照電極７との間の電位差が一定
となるように第１電極３と第２電極５との間の電圧を可
変とすることができるため、水素濃度が高いときには高
い電圧を印加し、水素濃度が低いときには低い電圧を印
加するように、任意に、広範囲の水素ガス濃度において
最適な電圧を第１電極３と第２電極５との間に印加する
ことができる。これによって、精度が高く広い範囲の水
素ガス濃度の測定が可能になる。When the applied voltage is controlled using the reference electrode 7 so that the potential difference between the first electrode 3 and the reference electrode 7 becomes constant, the potential difference between the first electrode 3 and the reference electrode 7 becomes constant. The voltage between the first electrode 3 and the second electrode 5 can be made variable so that a high voltage is applied when the hydrogen concentration is high, and a low voltage is applied when the hydrogen concentration is low. Optionally, an optimum voltage can be applied between the first electrode 3 and the second electrode 5 in a wide range of hydrogen gas concentration. This makes it possible to measure the hydrogen gas concentration in a wide range with high accuracy.

【００３２】また、被測定ガス中の温度やＨ2Ｏ濃度が
変化することによって、第１電極３と第２電極５との間
の抵抗が変化した場合においても、第１電極３と第２電
極５との間に印加する電圧を可変制御することが可能で
あるため、被測定ガス中の水素ガス、Ｈ2Ｏ、温度等に
関係する測定条件が大きく変化する場合においても、高
精度の水素ガス濃度の測定が可能となる。Further, even when the resistance between the first electrode 3 and the second electrode 5 changes due to the change in the temperature or H 2 O concentration in the gas to be measured, the first electrode 3 and the second electrode 5 are not changed. Since it is possible to variably control the voltage applied between the electrode 5 and the electrode 5, even when the measurement conditions related to the hydrogen gas in the gas to be measured, H 2 O, temperature, etc. change significantly, it is possible to achieve high accuracy. It is possible to measure the hydrogen gas concentration.

【００３３】ｃ）次に、本実施例の水素ガスセンサの製
造方法について簡単に説明する。例えば図１に示す様
に、基台（図示せず）上に、第２支持体９を、その第２
凹部１２側を上向きにして配置する。次に、その上に、
両側に第１電極３、第２電極５及び参照電極７を配置し
たプロトン伝導層１を配置する。つまり、第２電極５及
び参照電極７が、それぞれ、第２凹部１２及び第３凹部
１３内に収容されるように配置する。C) Next, a method for manufacturing the hydrogen gas sensor of this embodiment will be briefly described. For example, as shown in FIG. 1, a second support 9 is placed on a base (not shown),
The concave portion 12 side is arranged facing upward. Then on top of that,
The proton conducting layer 1 having the first electrode 3, the second electrode 5 and the reference electrode 7 arranged on both sides is arranged. That is, the second electrode 5 and the reference electrode 7 are arranged so as to be housed in the second recess 12 and the third recess 13, respectively.

【００３４】次に、第１電極３を第１凹部１１で囲むよ
うにして、プロトン伝導層１上に第１支持体８を配置す
る。この状態で、即ち、第１支持体８及び第２支持体９
でプロトン伝導層１を挟んだ状態で、図示しない固定部
材等で水素ガスセンサの厚み方向（同図の上下方向）に
押圧して固定し、水素ガスセンサとする。Next, the first support 8 is arranged on the proton conducting layer 1 so that the first electrode 3 is surrounded by the first recess 11. In this state, that is, the first support 8 and the second support 9
With the proton conductive layer 1 sandwiched in between, the hydrogen gas sensor is fixed by pressing it in the thickness direction of the hydrogen gas sensor (vertical direction in the figure) with a fixing member or the like (not shown).

【００３５】尚、水素ガスセンサの側面は、例えば樹脂
等により覆われ、拡散律速部１９以外からの通気ができ
ないように気密されているが、拡散律速部１９以外から
の（第１電極３側への）通気ができなければ良いので、
この方法に限定されるものではない。The side surface of the hydrogen gas sensor is covered with, for example, resin so as to be airtight so as to prevent ventilation from other than the diffusion rate controlling portion 19. It's good if you can't ventilate
The method is not limited to this.

【００３６】ｄ）次に、本実施例の水素ガスセンサの効
果について説明する。本実施例の水素ガスセンサは、第
２電極５を第１電極３に投影した場合に当該投影した部
分以外に存在する第１電極３の第１面積Ｓ１と、第２電
極５を第１電極３に投影した場合に当該第１電極３と重
なる第２電極５の第２面積Ｓ２との比（面積比）Ｓ１／
Ｓ２を、０．３５未満としている。D) Next, the effect of the hydrogen gas sensor of this embodiment will be described. In the hydrogen gas sensor of the present embodiment, when the second electrode 5 is projected onto the first electrode 3, the first area S1 of the first electrode 3 existing in a portion other than the projected portion and the second electrode 5 are replaced by the first electrode 3. Ratio (area ratio) S1 / of the second area S2 of the second electrode 5 overlapping the first electrode 3 when projected onto
S2 is set to less than 0.35.

【００３７】つまり、第１電極３と第２電極５とは、そ
の投影方向にて多くの部分が重なり合っているので、水
素がポンピングされにくい部分（参照電極７と対向する
第１電極３側の部分）の影響が小さくなる。その結果、
第１電極３と参照電極７との間を一定の電位差に制御す
る際に、水素の濃度が局所的に低い部分が発生しない。
これによって、メタノール等の解離等が起こることを防
止できるため、メタノール等による影響を受けず、正確
に水素ガスの濃度を測定することが可能となる。That is, since the first electrode 3 and the second electrode 5 overlap each other in the projection direction, a portion where hydrogen is difficult to be pumped (on the side of the first electrode 3 facing the reference electrode 7) is difficult. Effect) is reduced. as a result,
When controlling the potential difference between the first electrode 3 and the reference electrode 7 to be a constant potential difference, a portion where the hydrogen concentration is locally low does not occur.
As a result, dissociation of methanol or the like can be prevented, so that the concentration of hydrogen gas can be accurately measured without being affected by methanol or the like.

【００３８】更に本実施例では、第２電極５を第１電極
３に投影した場合に、第２電極５が第１電極３内に完全
に収容されるように形成されているので、つまり、第２
電極５の全ての部分が第１電極３と対向しているので、
第１電極３から第２電極５への水素のポンピングを効率
よく行うことができる。Further, in this embodiment, when the second electrode 5 is projected onto the first electrode 3, the second electrode 5 is formed so as to be completely housed in the first electrode 3, that is, Second
Since all parts of the electrode 5 face the first electrode 3,
It is possible to efficiently pump hydrogen from the first electrode 3 to the second electrode 5.

【００３９】ｅ）次に、本実施例の効果を確認するため
に行った実験例について説明する。この実験は、面積比
Ｓ１／Ｓ２を変更した場合において、水素ガス濃度の測
定精度を調べたものである。 まず、本発明の範囲のもの（本発明品）として、第２
面積Ｓ２を一定として第１面積Ｓ１を変更し、具体的に
は、面積比Ｓ１／Ｓ２を、「０ｍｍ2／１８ｍｍ2＝
０」、「３ｍｍ2／１８ｍｍ2＝約０．１７」、「６ｍｍ
2／１８ｍｍ2＝約０．３３」として、前記実施例と同様
な水素ガスセンサ（試料Ｎo.１〜３）を製造した。E) Next, an example of an experiment conducted to confirm the effect of this embodiment will be described. In this experiment, the measurement accuracy of the hydrogen gas concentration was examined when the area ratio S1 / S2 was changed. First, as a product within the scope of the present invention (product of the present invention), the second
The first area S1 to change the area S2 as constant, specifically, the area ratio S1 / S2, "0mm 2 / 18mm 2 =
0 "," 3mm 2 / 18mm 2 = about 0.17 "," 6mm
As 2/18 mm 2 = about 0.33 ", to produce the embodiment similar to hydrogen gas sensors (Sample No.1~3).

【００４０】一方、本発明の範囲外の試料（比較例品）
として、面積比Ｓ１／Ｓ２を、「９ｍｍ2／１８ｍｍ2＝
０．５」とし、他の部分は前記実施例と同様な水素ガス
センサ（試料Ｎo.４）を製造した。 そして、上述した本発明品及び比較例品の水素ガスセ
ンサを用いて、水素ガス濃度を測定し、その際の水素ガ
スセンサの精度、即ちメタノールの依存性を調べた。On the other hand, a sample outside the scope of the present invention (comparative example product)
As the area ratio S1 / S2, "9mm 2 / 18mm 2 =
0.5 ", and a hydrogen gas sensor (Sample No. 4) similar to that of the above-described example was manufactured in the other portions. Then, using the hydrogen gas sensors of the present invention product and the comparative product described above, the hydrogen gas concentration was measured, and the accuracy of the hydrogen gas sensor at that time, that is, the dependence of methanol was examined.

【００４１】具体的には、各水素ガスセンサを用いて、
前記ガス組成を有する被測定ガス中の水素ガス濃度を測
定する際において、第１電極と第２電極との間に流れる
電流値を測定した。測定条件は、下記の通りである。
尚、ここでは、水素ガス濃度を安定化させるために、第
１電極から参照電極に一定の微小な電流（例えば１０μ
Ａ）を流すことにより、参照電極を自己生成基準極とし
た。Specifically, using each hydrogen gas sensor,
When measuring the hydrogen gas concentration in the measured gas having the gas composition, the value of the current flowing between the first electrode and the second electrode was measured. The measurement conditions are as follows.
Here, in order to stabilize the hydrogen gas concentration, a constant minute current (for example, 10 μm) is applied from the first electrode to the reference electrode.
By flowing A), the reference electrode was used as a self-generated standard electrode.

【００４２】＜測定条件＞ ・ガス組成：Ｈ2＝５０％、ＣＯ2＝１５％、Ｈ2Ｏ＝１
０％、ＣＨ3ＯＨ＝０％又は５％、Ｎ2＝ｂａｌ． ・ガス温度：８０℃ ・ガス流量：１０Ｌ／ｍｉｎ ・設定電位Ｖｓ：１５０ｍＶ （第１電極と参照電極間の設定電位で、第１電極側を正
とする） そして、上述した測定条件のもとで測定した、ＣＨ3Ｏ
Ｈ＝０％時の電流値（Ａ０）とＣＨ3ＯＨ＝５％時の電
流値（Ａ５）とを用いて、電流値比（Ａ５／Ａ０）、即
ち、ＣＨ3ＯＨ＝０％時の電流値（感度）を１とした時
のＣＨ3ＯＨ＝５％時の電流値（感度）比を求めた。<Measurement conditions> Gas composition: H 2 = 50%, CO 2 = 15%, H 2 O = 1
0%, CH 3 OH = 0% or 5%, N 2 = bal. -Gas temperature: 80 ° C-Gas flow rate: 10 L / min-Set potential Vs: 150 mV (set potential between the first electrode and the reference electrode, the first electrode side being positive) And under the measurement conditions described above. CH 3 O measured at
With H = 0% when the current value (A0) and CH 3 OH = 5% when the current value of the (A5), the current value ratio (A5 / A0), i.e., CH 3 OH = 0% at a current When the value (sensitivity) was set to 1, the current value (sensitivity) ratio when CH 3 OH = 5% was determined.

【００４３】前記測定結果を、図３に示すが、この図
３は、縦軸に電流値比をとり、横軸に面積比Ｓ１／Ｓ２
をとったものである。図３から、本発明品の試料Ｎo.１
〜３の水素ガスセンサ、即ち、面積比Ｓ１／Ｓ２が０．
３５未満のものものは、そうでない比較品の試料Ｎo.４
の水素ガスセンサに比べて、その電流値比が極めて小さ
くなっており、その精度が高いことが分かる。The measurement results are shown in FIG. 3. In FIG. 3, the vertical axis represents the current value ratio and the horizontal axis represents the area ratio S1 / S2.
Is taken. From FIG. 3, sample No. 1 of the product of the present invention
3 to 3, that is, the area ratio S1 / S2 is 0.
Those of less than 35 are samples No. 4 of comparative products which are not so.
Compared with the hydrogen gas sensor of No. 2, the current value ratio is extremely small, and it can be seen that the accuracy is high.

【００４４】以上のことから明らかなように、面積比Ｓ
１／Ｓ２を０．３５未満とすることにより、メタノール
の解離を抑制でき、精度良く水素ガス濃度の測定を行う
ことができることが分かる。従って、本実施例の水素ガ
スセンサにより、固体高分子型燃料電池の燃料ガス中の
水素ガス濃度の測定を、メタノール等の影響を受けずに
精度良く行うことが可能である。 （実施例２）次に、実施例２について説明するが、前記
実施例と同様な箇所の説明は省略する。As is clear from the above, the area ratio S
It can be seen that by setting 1 / S2 to be less than 0.35, dissociation of methanol can be suppressed and the hydrogen gas concentration can be accurately measured. Therefore, with the hydrogen gas sensor of this embodiment, it is possible to accurately measure the hydrogen gas concentration in the fuel gas of the polymer electrolyte fuel cell without being affected by methanol or the like. (Embodiment 2) Next, Embodiment 2 will be described, but the description of the same parts as those in the above-mentioned embodiment will be omitted.

【００４５】本実施例の水素ガスセンサでは、第１電極
と第２電極との配置及び位置関係が異なる。図４に示す
様に、本実施例では、第１電極３１と第２電極３３と
は、その重なり合う方向（同図の上下方向）において、
多少左右にずれている。つまり、第２電極３３を第１電
極３１に投影した場合には、第２電極３３は第１電極３
１以内に完全に収まらず、第１電極３１への投影部分以
外にも広がっている。In the hydrogen gas sensor of this embodiment, the arrangement and positional relationship between the first electrode and the second electrode are different. As shown in FIG. 4, in the present embodiment, the first electrode 31 and the second electrode 33 are arranged in the overlapping direction (vertical direction in the figure).
It is slightly offset to the left and right. That is, when the second electrode 33 is projected onto the first electrode 31, the second electrode 33 is
It does not completely fit within 1 and extends beyond the projected portion on the first electrode 31.

【００４６】この場合には、第１電極３１の第１面積Ｓ
１は、投影によっても重ならない部分（同図のメッシュ
部分）であり、第２電極３３の第２面積Ｓ２は、前記投
影により重なる部分（同図の斜線部分）である。本実施
例も、面積比Ｓ１／Ｓ２は０．３５未満であるので、前
記実施例１とほぼ同様な効果を奏する。 （実施例３）次に、実施例３について説明するが、前記
実施例と同様な箇所の説明は省略する。In this case, the first area S of the first electrode 31 is
Reference numeral 1 denotes a portion that does not overlap even by projection (mesh portion in the figure), and the second area S2 of the second electrode 33 is a portion that overlaps by the projection (hatched portion in the figure). Also in this embodiment, since the area ratio S1 / S2 is less than 0.35, substantially the same effect as that of the first embodiment can be obtained. (Third Embodiment) Next, a third embodiment will be described, but the description of the same parts as those in the above-mentioned embodiment will be omitted.

【００４７】本実施例の水素ガスセンサでは、第１電極
と第２電極との配置及び位置関係が異なる。図５に示す
様に、本実施例では、第１電極４１と第２電極４３と
は、第２電極４３を第１電極４１に投影した場合には、
第２電極４３は縦横とも第１電極４１内に完全に収まる
ように設定されている。In the hydrogen gas sensor of this embodiment, the arrangement and positional relationship between the first electrode and the second electrode are different. As shown in FIG. 5, in this embodiment, when the second electrode 43 is projected onto the first electrode 41, the first electrode 41 and the second electrode 43 are
The second electrode 43 is set so as to fit completely inside the first electrode 41 in both the vertical and horizontal directions.

【００４８】この場合には、第１電極４１の第１面積Ｓ
１は、投影によっても重ならない部分（同図のメッシュ
部分）であり、第２電極４３の第２面積Ｓ２は、前記投
影により重なる部分（同図の斜線部分）、即ち第２電極
４３全体である。本実施例も、面積比Ｓ１／Ｓ２は０．
３５未満であるので、前記実施例１、２とほぼ同様な効
果を奏する。In this case, the first area S of the first electrode 41 is
Reference numeral 1 denotes a portion that does not overlap even by projection (mesh portion in the figure), and the second area S2 of the second electrode 43 is a portion that overlaps by the projection (hatched portion in the figure), that is, the entire second electrode 43. is there. Also in this embodiment, the area ratio S1 / S2 is 0.
Since it is less than 35, the same effects as those of the first and second embodiments are obtained.

【００４９】尚、本発明は前記実施例になんら限定され
るものではなく、本発明の要旨を逸脱しない範囲におい
て種々の態様で実施しうることはいうまでもない。例え
ば前記実施例では、水素ガスセンサにより、燃料ガス中
の水素ガス濃度を測定する場合を例に挙げたが、本発明
のガスセンサは、燃料ガス中のＣＯのガス濃度を測定す
る場合にも適用できる。Needless to say, the present invention is not limited to the above-mentioned embodiments, and can be carried out in various modes without departing from the gist of the present invention. For example, in the above-described embodiment, the case where the hydrogen gas sensor measures the hydrogen gas concentration in the fuel gas has been described as an example, but the gas sensor of the present invention is also applicable to the case where the CO gas concentration in the fuel gas is measured. .

【図面の簡単な説明】[Brief description of drawings]

【図１】 実施例１の水素ガスセンサを破断して示す説
明図である。FIG. 1 is an explanatory view showing a hydrogen gas sensor of Example 1 in a cutaway manner.

【図２】 第１電極と第２電極との関係を示す斜視図で
ある。FIG. 2 is a perspective view showing a relationship between a first electrode and a second electrode.

【図３】 実験結果を示すグラフである。FIG. 3 is a graph showing experimental results.

【図４】 実施例２における第１電極と第２電極との関
係を示す斜視図である。FIG. 4 is a perspective view showing a relationship between a first electrode and a second electrode in the second embodiment.

【図５】 実施例３における第１電極と第２電極との関
係を示す斜視図である。FIG. 5 is a perspective view showing a relationship between a first electrode and a second electrode in the third embodiment.

【図６】 従来の水素ガスセンサを破断して示す説明図
である。FIG. 6 is an explanatory view showing a conventional hydrogen gas sensor in a broken manner.

【符号の説明】[Explanation of symbols]

１…プロトン伝導層 ３、３１、４１…第１電極 ５、３３、４３…第２電極 ７…参照電極 １９…拡散律速部 1 ... Proton conduction layer 3, 31, 41 ... First electrode 5, 33, 43 ... Second electrode 7 ... Reference electrode 19 ... diffusion rate control

───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.7 識別記号 ＦＩ テーマコート゛(参考） Ｇ０１Ｎ 27/46 ３１１Ｚ (72)発明者 灘浪 紀彦 愛知県名古屋市瑞穂区高辻町14番18号 日 本特殊陶業株式会社内 (72)発明者 渡辺 昌哉 愛知県名古屋市瑞穂区高辻町14番18号 日 本特殊陶業株式会社内 (72)発明者 石田 昇 愛知県名古屋市瑞穂区高辻町14番18号 日 本特殊陶業株式会社内 Ｆターム(参考） 5H026 AA06 5H027 AA06 KK31 ─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. 7 Identification code FI theme code (reference) G01N 27/46 311Z (72) Inventor Norihiko Nadanami 14-18 Takatsuji-cho, Mizuho-ku, Aichi Prefecture Special Ceramics Co., Ltd. (72) Inventor Masaya Watanabe 14-18 Takatsuji-cho, Mizuho-ku, Nagoya-shi, Aichi Japan Special Ceramics Co., Ltd. (72) Noboru Ishida 14-18 Takatsuji-cho, Mizuho-ku, Nagoya-shi, Aichi F-Term (Reference) within Nihon Special Ceramics Co., Ltd. (reference) 5H026 AA06 5H027 AA06 KK31

Claims (4)

【特許請求の範囲】[Claims] 【請求項１】 プロトン伝導層に接して設けられた第１
電極、第２電極及び参照電極と、被測定ガス雰囲気及び
前記第１電極の間に設けられた拡散律速部と、を有し、 前記被測定ガス雰囲気側から前記拡散律速部を介して導
入された被測定ガス中の測定対象ガスを、前記第１電極
と前記参照電極との間の電位差が一定になるように、前
記第１電極と前記第２電極との間に電圧を印加すること
により、解離又は分解もしくは反応させ、それによって
発生したプロトンを、前記プロトン伝導層を介して前記
第１電極側から前記第２電極側へ汲み出すことにより生
じる限界電流に基づいて、前記測定対象ガスの濃度を求
めるガスセンサにおいて、 前記第１電極と前記第２電極とが前記プロトン伝導層を
挟んで対向する構造を有するとともに、前記第２電極を
前記第１電極に投影した場合に当該投影した部分以外に
存在する前記第１電極の第１面積Ｓ１と、前記第２電極
を前記第１電極に投影した場合に当該第１電極と重なる
前記第２電極の第２面積Ｓ２との比Ｓ１／Ｓ２を、０．
３５未満としたことを特徴とするガスセンサ。1. A first device provided in contact with the proton conducting layer.
An electrode, a second electrode, and a reference electrode, and a diffusion rate controlling part provided between the measured gas atmosphere and the first electrode, and introduced from the measured gas atmosphere side through the diffusion rate controlling part. The measurement target gas in the measurement target gas is applied with a voltage between the first electrode and the second electrode such that the potential difference between the first electrode and the reference electrode is constant. , Dissociation or decomposition or reaction, and the protons generated thereby are pumped from the first electrode side to the second electrode side through the proton conductive layer, based on the limiting current generated, In a gas sensor for determining the concentration, the first electrode and the second electrode have a structure in which they are opposed to each other with the proton conducting layer interposed therebetween, and when the second electrode is projected onto the first electrode, the projection is performed. The ratio S1 / of the first area S1 of the first electrode existing other than the first area and the second area S2 of the second electrode which overlaps the first electrode when the second electrode is projected onto the first electrode. S2 to 0.
A gas sensor characterized by being less than 35. 【請求項２】 前記第２電極を前記第１電極に投影した
場合に、前記第１電極及び前記第２電極のうち、面積の
小さい方の電極が大きい方の電極の投影領域内にあるよ
うに、前記第１電極及び前記第２電極を設けたことを特
徴とする前記請求項１に記載のガスセンサ。2. When the second electrode is projected onto the first electrode, the electrode having the smaller area of the first electrode and the second electrode is within the projection area of the electrode having the larger area. The gas sensor according to claim 1, wherein the first electrode and the second electrode are provided in the gas sensor. 【請求項３】 前記ガスセンサは、水素ガス濃度を測定
する水素ガスセンサであることを特徴とする前記請求項
１又は２に記載のガスセンサ。3. The gas sensor according to claim 1, wherein the gas sensor is a hydrogen gas sensor that measures a hydrogen gas concentration. 【請求項４】 前記ガスセンサは、固体高分子型燃料電
池の燃料ガス中の水素ガス濃度測定に用いられるもので
あることを特徴とする前記請求項３に記載のガスセン
サ。4. The gas sensor according to claim 3, wherein the gas sensor is used for measuring a hydrogen gas concentration in a fuel gas of a polymer electrolyte fuel cell.
JP2001344781A 2001-09-03 2001-11-09 Gas sensor Pending JP2003149191A (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
JP2001344781A JP2003149191A (en) 2001-11-09 2001-11-09 Gas sensor
CA002400882A CA2400882A1 (en) 2001-09-03 2002-08-29 Gas sensor
US10/231,209 US20030042139A1 (en) 2001-09-03 2002-08-30 Gas sensor
EP02256064A EP1288655A3 (en) 2001-09-03 2002-09-02 Gas sensor

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2001344781A JP2003149191A (en) 2001-11-09 2001-11-09 Gas sensor

Publications (1)

Publication Number Publication Date
JP2003149191A true JP2003149191A (en) 2003-05-21

Family

ID=19158249

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2001344781A Pending JP2003149191A (en) 2001-09-03 2001-11-09 Gas sensor

Country Status (1)

Country Link
JP (1) JP2003149191A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006278246A (en) * 2005-03-30 2006-10-12 Honda Motor Co Ltd Control method of fuel cell stack
JP2019029170A (en) * 2017-07-28 2019-02-21 ウシオ電機株式会社 Impurity sensor for fuel battery cell

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006278246A (en) * 2005-03-30 2006-10-12 Honda Motor Co Ltd Control method of fuel cell stack
JP2019029170A (en) * 2017-07-28 2019-02-21 ウシオ電機株式会社 Impurity sensor for fuel battery cell

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