JPH0618467A - Gas sensor - Google Patents
Gas sensorInfo
- Publication number
- JPH0618467A JPH0618467A JP19608592A JP19608592A JPH0618467A JP H0618467 A JPH0618467 A JP H0618467A JP 19608592 A JP19608592 A JP 19608592A JP 19608592 A JP19608592 A JP 19608592A JP H0618467 A JPH0618467 A JP H0618467A
- Authority
- JP
- Japan
- Prior art keywords
- gas
- gas sensor
- metal oxide
- sensitivity
- oxide semiconductor
- 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.)
- Granted
Links
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は特に硫化水素（Ｈ
2Ｓ）、メルカプタン等の硫黄系ガスを検出するための
ガスセンサに関する。The present invention is particularly applicable to hydrogen sulfide (H
2 S), a gas sensor for detecting a sulfur-based gas such as mercaptan.
【０００２】[0002]
【従来の技術】ガスの吸脱着により抵抗値が変化する金
属酸化物半導体（ＳnＯ2）に電極を接続し、抵抗値を測
定することでガスの有無を検出するようにした半導体ガ
スセンサが従来からガス漏れ警報器等として使用されて
いる。2. Description of the Related Art A semiconductor gas sensor has been conventionally used in which an electrode is connected to a metal oxide semiconductor (SnO 2 ) whose resistance value changes due to adsorption and desorption of gas, and the presence or absence of gas is detected by measuring the resistance value. It is used as a gas leak alarm.
【０００３】一方、最近ではトイレやキッチン等の住居
内におけるオートベンチレーション（自動換気）を行な
うためのガスセンサの開発が要望されている。つまり、
トイレやキッチン等の悪臭成分の主なものは、Ｈ2Ｓ、
アンモニア、アミン類及びメルカプタン類であり、快適
な住環境を維持するにはこれらのガス濃度が数ｐｐｂ〜
数ｐｐｍの範囲で検出できるセンサが必要とされる。し
かしながら従来の金属酸化物半導体ガスセンサによる検
出可能濃度は数百ｐｐｍ以上である。On the other hand, recently, there has been a demand for development of a gas sensor for performing automatic ventilation in a house such as a toilet or a kitchen. That is,
The main offensive odor components in toilets and kitchens are H 2 S,
Ammonia, amines, and mercaptans, and these gas concentrations are several ppb to maintain a comfortable living environment.
A sensor capable of detecting in the range of several ppm is required. However, the detectable concentration by the conventional metal oxide semiconductor gas sensor is several hundred ppm or more.
【０００４】そこで、特開昭６３−３１３０４８号及び
特開昭６３ー３１３０４９号には、Ｓnのアルコキシド
溶液を絶縁基板に塗布した後、アルコキシド溶液を熱分
解してＳnＯ2を形成し、このＳnＯ2膜に別の金属（通
常、酸化物の形態となっている）を添加して、ガス検出
感度を高めるようにした提案がなされている。Therefore, in JP-A-63-313048 and JP-A-63-313049, an alkoxide solution of Sn is applied to an insulating substrate and then the alkoxide solution is thermally decomposed to form SnO 2. It has been proposed that another metal (usually in the form of an oxide) be added to the two films to enhance the gas detection sensitivity.
【０００５】[0005]
【発明が解決しようとする課題】しかし上述した方法で
は、ガス感度は比較的良好であるものの雰囲気をＨ2Ｓ
から空気に切り替えた時の回復応答性が悪い。一方セン
サ温度を４００℃まで高めれば回復応答性は良くなる
が、今度は急激にガス感度が低下する。回復応答性を高
めるためにセンサを加熱するヒートクリーンニングも知
られているが、この場合には連続測定ができず、またヒ
ートクリーンニング用の別回路が必要となる等の難点が
あった。。However, in the above method, the gas sensitivity is relatively good, but the atmosphere is H 2 S.
The recovery response when switching from air to air is poor. On the other hand, if the sensor temperature is increased to 400 ° C., the recovery response is improved, but this time, the gas sensitivity sharply decreases. Heat cleaning in which a sensor is heated in order to improve recovery response is also known, but in this case, continuous measurement cannot be performed, and a separate circuit for heat cleaning is required. .
【０００６】[0006]
【課題を解決するための手段】上記課題を解決すべく本
発明は、硫黄系ガスが吸脱着する金属酸化物半導体の主
体をＷＯ3とし、この金属酸化物に加える添加物をＰt、
Ｒu、Ａu、Ａg、Ｒh及びＰdのうちの少なくとも１種と
した。In order to solve the above problems, the present invention uses WO 3 as the main component of a metal oxide semiconductor that adsorbs and desorbs a sulfur-based gas, and Pt is an additive added to this metal oxide.
At least one of Ru, Au, Ag, Rh and Pd is used.
【０００７】[0007]
【作用】ガスセンサの主体となる金属酸化物を従来のＳ
nＯ2から酸性の強いＷＯ3に変えることで、Ｈ2Ｓ、メル
カプタン等の硫黄系ガスに対する感度が大幅に向上す
る。[Function] The metal oxide, which is the main component of the gas sensor, is replaced by the conventional S
By changing from nO 2 to WO 3 having strong acidity, the sensitivity to sulfur-based gas such as H 2 S and mercaptan is significantly improved.
【０００８】[0008]
【実施例】以下に本発明の実施例を添付図面に基づいて
説明する。ここで図１は本発明に係るガスセンサの一例
を示す斜視図、図２は同ガスセンサの一部拡大断面図で
ある。また図３は本発明に係るガスセンサの他の例を示
す斜視図である。Embodiments of the present invention will be described below with reference to the accompanying drawings. Here, FIG. 1 is a perspective view showing an example of a gas sensor according to the present invention, and FIG. 2 is a partially enlarged sectional view of the gas sensor. FIG. 3 is a perspective view showing another example of the gas sensor according to the present invention.
【０００９】図１及び図２に示すガスセンサ１はアルミ
ナ基板２に一対の櫛形Ａu電極３，３を焼成により形成
し、このＡu電極３，３が接続する金属酸化物半導体層
４を同じく焼成によりアルミナ基板２表面に形成し、更
にアルミナ基板２内にはヒータ５を埋設している。この
金属酸化物半導体層４はＷＯ3にＰt、Ｒu、Ａu、Ａg、
Ｒh及びＰdのうちの少なくとも１種を添加している。
尚、アルミナ等の基板に金属酸化物半導体層を薄膜状に
形成せず、ある程度の厚みの金属酸化物半導体層に直接
電極を埋設してもよい。In the gas sensor 1 shown in FIGS. 1 and 2, a pair of comb-shaped Au electrodes 3 are formed on an alumina substrate 2 by firing, and a metal oxide semiconductor layer 4 connected to the Au electrodes 3, 3 is also fired. It is formed on the surface of the alumina substrate 2, and a heater 5 is embedded in the alumina substrate 2. The metal oxide semiconductor layer 4 is made of WO 3 containing Pt, Ru, Au, Ag,
At least one of Rh and Pd is added.
The metal oxide semiconductor layer may not be formed into a thin film on a substrate such as alumina, but the electrode may be directly embedded in the metal oxide semiconductor layer having a certain thickness.
【００１０】この金属酸化物半導体層４の製法について
以下に述べる。先ず、パラタングステン酸アンモニウム
｛（ＮＨ4）10Ｗ12Ｏ41・５Ｈ2Ｏ｝を出発原料とし、こ
れを空気中で６００℃．５時間熱分解してＷＯ3の粉末
試料を得る。次いで、この粉末試料にＰt、Ｒu、Ａu、
Ａg、ＲhまたはＰdを添加し、空気中で６００℃、５時
間焼成して得た粉末をビヒクルとともに混練して成形し
た後焼成することで金属酸化物半導体層４を形成する。
尚、Ｐt、Ｒu、Ａu、Ａg、Ｒh、Ｐdの添加には、含浸法
やコロイド吸着法が用いられる。A method of manufacturing the metal oxide semiconductor layer 4 will be described below. First, ammonium paratungstate and {(NH 4) 10 W 12 O 41 · 5H 2 O} as a starting material, which 600 ° C. in air. Pyrolysis for 5 hours gives a powder sample of WO 3 . Then, Pt, Ru, Au,
The metal oxide semiconductor layer 4 is formed by adding Ag, Rh, or Pd, and kneading the powder obtained by firing in air at 600 ° C. for 5 hours with a vehicle, shaping the powder, and firing.
An impregnation method or a colloid adsorption method is used to add Pt, Ru, Au, Ag, Rh, and Pd.
【００１１】図３に示すガスセンサ１１は筒状アルミナ
管１２に一対のＰt線１３，１３を巻回し、このＰt線１
３，１３を包むようにＷＯ3にＰt、Ｒu、Ａu、Ａg、Ｒh
及びＰdのうちの少なくとも１種を添加してなる多孔質
焼結体からなる金属酸化物半導体層１４を形成してい
る。In the gas sensor 11 shown in FIG. 3, a pair of Pt wires 13 and 13 are wound around a cylindrical alumina tube 12 to form a Pt wire 1.
Pt, Ru, Au, Ag, Rh in WO 3 to wrap 3,3
And at least one of Pd is added to form the metal oxide semiconductor layer 14 made of a porous sintered body.
【００１２】上記添加物のうち、Ａuは応答性及びガス
感度のいずれにおいても良好な結果であった。そこで、
Ａuを添加した素子について下記の実験を行った。図４
は、ＷＯ3にＡuを０．５重量％添加して形成した素子
（以後、ＷＯ3−０．５Ａu素子と表記する）のＨ2Ｓ濃
度１ppm雰囲気中における、素子温度とガス感度との関
係を調べた結果である。ここでガス感度は空気中におけ
る抵抗値Ｒaと被検ガス（硫化水素やメルカプタンを含
む空気）中における抵抗値Ｒsとの比Ｓ＝Ｒa／Ｒsで表
わすようにした。Among the above additives, Au showed good results both in response and gas sensitivity. Therefore,
The following experiment was conducted on the element to which Au was added. Figure 4
An element formed by adding 0.5% by weight of Au on WO3 (hereinafter, referred to as WO 3 -0.5Au elements) in H2S concentration 1ppm atmosphere was investigated the relationship between the device temperature and the gas sensitivity The result. Here, the gas sensitivity is represented by a ratio S = Ra / Rs of a resistance value Ra in air and a resistance value Rs in a test gas (air containing hydrogen sulfide or mercaptan).
【００１３】図５はＷＯ3へのＡu添加量とガス感度との
関係を調べたものであり、素子温度は３００℃に設定
し、Ｈ2Ｓ濃度１ppm雰囲気中で測定した。同図から、Ａ
u添加量は０．５重量％前後が最も適量でありガス感度
が高くなることが分かった。FIG. 5 shows the relationship between the amount of Au added to WO 3 and the gas sensitivity. The device temperature was set to 300 ° C. and the H 2 S concentration was measured in an atmosphere of 1 ppm. From the figure, A
It was found that the optimum amount of u added was around 0.5% by weight, and the gas sensitivity was high.
【００１４】図６は、添加物なしのＷＯ3素子、及びＷ
Ｏ3−０．５Ａu素子について、素子温度３００℃で、Ｈ
2Ｓ濃度（ppb）とガス感度との関係を調べたものであ
る。同図からＨ2Ｓ濃度の対数値と素子のガス感度の対
数値とは直線関係にあり、本発明に基づくＷＯ3−０．
５Ａu素子はＷＯ3単独素子と比較して約１／５０の薄い
Ｈ2Ｓ濃度を同感度で検知できることが分かった。FIG. 6 shows a WO 3 device without additives, and W
Regarding the O 3 -0.5Au element, at an element temperature of 300 ° C., H
The relationship between 2 S concentration (ppb) and gas sensitivity was investigated. Located linear relationship between the logarithmic value of the gas sensitivity of the logarithmic value and the element of H2S concentration from the figure, according to the present invention WO 3 -0.
It was found that the 5Au element can detect a thin H 2 S concentration of about 1/50 as compared with the WO 3 single element with the same sensitivity.
【００１５】図７は本発明に基づくＷＯ3−０．５Ａu素
子について、素子温度３００℃で、メチルメルカプタン
濃度（ppb）とガス感度との関係を調べたものである。
同図から明らかなように、メチルメルカプタン濃度の対
数値と素子のガス感度の対数値とはＨ2Ｓの場合と同じ
く直線関係にあり、Ｈ2Ｓとほとんど変らない高いガス
感度を示した。FIG. 7 shows the relationship between the methyl mercaptan concentration (ppb) and the gas sensitivity at a device temperature of 300 ° C. for the WO 3 -0.5Au device according to the present invention.
As apparent from the figure, the logarithmic value of the gas sensitivity of the logarithmic value and the element of methyl mercaptan concentration is in the same linear relationship as in the H 2 S, it exhibited a high gas sensitivity unchanged almost the H 2 S.
【００１６】図８はＨ2Ｓ濃度０．１ppmに対する本発明
に基づくＷＯ3−０．５Ａu素子の応答曲線であり、縦軸
は素子抵抗の変化率（Ｒ／Ｒ0）の対数値で表してあ
る。同図から、この素子は臭気発生から僅か１分程度で
臭気を感知することができ、また回復速度も、ヒートク
リーニングを用いなくても４分程度で完全に回復するこ
とのできる優秀なものであることが分かった。FIG. 8 is a response curve of the WO 3 -0.5Au element according to the present invention with respect to the H 2 S concentration of 0.1 ppm, and the vertical axis is expressed by the logarithmic value of the change rate (R / R 0) of the element resistance. is there. From the figure, this element is capable of detecting an odor in about 1 minute from the generation of odor, and has an excellent recovery speed that it can completely recover in about 4 minutes without using heat cleaning. I knew it was.
【００１７】[0017]
【発明の効果】以上に説明した如く本発明によれば、金
属酸化物半導体ガスセンサを構成する主体となる金属酸
化物としてＷＯ3を選定し、これにＰt、Ｒu、Ａu、Ａ
g、Ｒh及びＰdのうちの少なくとも１種を添加したこと
で、Ｈ2Ｓ、メルカプタン等の硫黄系ガスに対するセン
サの感度を大幅に高めることができ、更に応答速度及び
回復速度の双方に優れたガスセンサとすることができ
る。As described above, according to the present invention, WO 3 is selected as the main metal oxide constituting the metal oxide semiconductor gas sensor, and Pt, Ru, Au, A
By adding at least one of g, Rh, and Pd, the sensitivity of the sensor to sulfur-based gas such as H 2 S and mercaptan can be significantly improved, and both the response speed and the recovery speed are excellent. It can be a gas sensor.
【図１】本発明に係るガスセンサの一例を示す斜視図FIG. 1 is a perspective view showing an example of a gas sensor according to the present invention.
【図２】同ガスセンサの一部拡大断面図FIG. 2 is a partially enlarged sectional view of the gas sensor.
【図３】同ガスセンサの他の例を示す斜視図FIG. 3 is a perspective view showing another example of the gas sensor.
【図４】同ガスセンサのＨ2Ｓに対する素子温度とガス
感度との関係を示すグラフFIG. 4 is a graph showing a relationship between element temperature and gas sensitivity with respect to H 2 S of the gas sensor.
【図５】同ガスセンサのＨ2Ｓに対するＡu添加量とガス
感度との関係を示すグラフFIG. 5 is a graph showing the relationship between the amount of Au added to H 2 S and the gas sensitivity of the gas sensor.
【図６】同ガスセンサのＨ2Ｓ濃度とガス感度との関係
を示すグラフFIG. 6 is a graph showing the relationship between H 2 S concentration and gas sensitivity of the gas sensor.
【図７】同ガスセンサのメチルメルカプタン濃度とガス
感度との関係を示すグラフFIG. 7 is a graph showing the relationship between the methyl mercaptan concentration and gas sensitivity of the gas sensor.
【図８】同ガスセンサのＨ2Ｓに対する応答曲線を示す
グラフFIG. 8 is a graph showing a response curve of the gas sensor to H 2 S.
１、１１…ガスセンサ、２、１２…アルミナ基板、３、
１３…電極、４、１４…金属酸化物半導体層、５…ヒー
タ。1, 11 ... Gas sensor, 2, 12 ... Alumina substrate, 3,
13 ... Electrodes, 4 and 14 ... Metal oxide semiconductor layers, 5 ... Heaters.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 三浦 則雄 福岡県福岡市中央区平尾３−17−５−301 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Norio Miura 3-17-5-301 Hirao, Chuo-ku, Fukuoka-shi, Fukuoka
Claims (1)
金属酸化物半導体に対するガスの吸脱着による抵抗値の
変化を利用したガスセンサにおいて、前記ガスは硫黄系
ガスであり、更に前記主体となる金属酸化物をＷＯ3と
し、添加物をＰt、Ｒu、Ａu、Ａg、Ｒh及びＰdのうちの
少なくとも１種としたことを特徴とするガスセンサ。1. A gas sensor utilizing a change in resistance value due to adsorption and desorption of a gas with respect to a metal oxide semiconductor obtained by adding an additive to a main metal oxide, wherein the gas is a sulfur-based gas, and The gas sensor, wherein the metal oxide is WO 3 , and the additive is at least one of Pt, Ru, Au, Ag, Rh, and Pd.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19608592A JP3191420B2 (en) | 1992-06-30 | 1992-06-30 | Gas sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19608592A JP3191420B2 (en) | 1992-06-30 | 1992-06-30 | Gas sensor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0618467A true JPH0618467A (en) | 1994-01-25 |
| JP3191420B2 JP3191420B2 (en) | 2001-07-23 |
Family
ID=16351963
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP19608592A Expired - Fee Related JP3191420B2 (en) | 1992-06-30 | 1992-06-30 | Gas sensor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3191420B2 (en) |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2003029801A1 (en) * | 2001-09-28 | 2003-04-10 | Shinko Electric Industries Co., Ltd. | Sulfur component sensor and sulfur component detector |
| JP2003130832A (en) * | 2001-10-23 | 2003-05-08 | Shinko Electric Ind Co Ltd | Sensor and detector for detecting sulfur |
| KR100477422B1 (en) * | 2002-01-11 | 2005-03-23 | 동양물산기업 주식회사 | Method for semiconductor thin film gas sensor in order to detecting an ammonia gas and its device |
| WO2006007802A1 (en) * | 2004-07-20 | 2006-01-26 | T.E.M.. Technologische Entwicklungen Und Management Gmbh | Sensor for detecting airborne gases or fumes, which comprises a metal oxide, gas-sensitive active layer |
| JP2009519470A (en) * | 2005-12-12 | 2009-05-14 | ネクステック、マテリアルズ、リミテッド | Ceramic H2S sensor |
| JP2010043905A (en) * | 2008-08-11 | 2010-02-25 | Sumitomo Electric Ind Ltd | Gas sensor |
| KR101104215B1 (en) * | 2009-06-30 | 2012-01-10 | 한국이엔에쓰 주식회사 | manufacturing method of Gas sensor for sensing sulfuration compound |
| JP2016145810A (en) * | 2015-01-30 | 2016-08-12 | Toto株式会社 | Biological information measurement system |
| JP2021012110A (en) * | 2019-07-08 | 2021-02-04 | フィガロ技研株式会社 | Reforming method of wo3-based gas sensor |
-
1992
- 1992-06-30 JP JP19608592A patent/JP3191420B2/en not_active Expired - Fee Related
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2003029801A1 (en) * | 2001-09-28 | 2003-04-10 | Shinko Electric Industries Co., Ltd. | Sulfur component sensor and sulfur component detector |
| JP2003130832A (en) * | 2001-10-23 | 2003-05-08 | Shinko Electric Ind Co Ltd | Sensor and detector for detecting sulfur |
| KR100477422B1 (en) * | 2002-01-11 | 2005-03-23 | 동양물산기업 주식회사 | Method for semiconductor thin film gas sensor in order to detecting an ammonia gas and its device |
| WO2006007802A1 (en) * | 2004-07-20 | 2006-01-26 | T.E.M.. Technologische Entwicklungen Und Management Gmbh | Sensor for detecting airborne gases or fumes, which comprises a metal oxide, gas-sensitive active layer |
| JP2009519470A (en) * | 2005-12-12 | 2009-05-14 | ネクステック、マテリアルズ、リミテッド | Ceramic H2S sensor |
| JP2010043905A (en) * | 2008-08-11 | 2010-02-25 | Sumitomo Electric Ind Ltd | Gas sensor |
| KR101104215B1 (en) * | 2009-06-30 | 2012-01-10 | 한국이엔에쓰 주식회사 | manufacturing method of Gas sensor for sensing sulfuration compound |
| JP2016145810A (en) * | 2015-01-30 | 2016-08-12 | Toto株式会社 | Biological information measurement system |
| JP2021012110A (en) * | 2019-07-08 | 2021-02-04 | フィガロ技研株式会社 | Reforming method of wo3-based gas sensor |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3191420B2 (en) | 2001-07-23 |
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