JPH04335149A - Gas sensor - Google Patents
Gas sensorInfo
- Publication number
- JPH04335149A JPH04335149A JP13567891A JP13567891A JPH04335149A JP H04335149 A JPH04335149 A JP H04335149A JP 13567891 A JP13567891 A JP 13567891A JP 13567891 A JP13567891 A JP 13567891A JP H04335149 A JPH04335149 A JP H04335149A
- Authority
- JP
- Japan
- Prior art keywords
- gas sensor
- metal oxide
- gas
- oxide semiconductor
- anatase
- 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.)
- Withdrawn
Links
- 229910044991 metal oxide Inorganic materials 0.000 claims abstract description 23
- 150000004706 metal oxides Chemical class 0.000 claims abstract description 23
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 claims abstract description 20
- 239000004065 semiconductor Substances 0.000 claims abstract description 18
- ZKATWMILCYLAPD-UHFFFAOYSA-N niobium pentoxide Chemical compound O=[Nb](=O)O[Nb](=O)=O ZKATWMILCYLAPD-UHFFFAOYSA-N 0.000 claims abstract description 12
- 238000003795 desorption Methods 0.000 claims description 2
- 238000001179 sorption measurement Methods 0.000 claims description 2
- 230000035945 sensitivity Effects 0.000 abstract description 11
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 abstract description 8
- 239000000758 substrate Substances 0.000 abstract description 6
- 238000001354 calcination Methods 0.000 abstract 2
- 239000007789 gas Substances 0.000 description 37
- RWSOTUBLDIXVET-UHFFFAOYSA-N Dihydrogen sulfide Chemical compound S RWSOTUBLDIXVET-UHFFFAOYSA-N 0.000 description 10
- 229910000037 hydrogen sulfide Inorganic materials 0.000 description 9
- XOLBLPGZBRYERU-UHFFFAOYSA-N tin dioxide Chemical compound O=[Sn]=O XOLBLPGZBRYERU-UHFFFAOYSA-N 0.000 description 6
- 238000011084 recovery Methods 0.000 description 4
- QTBSBXVTEAMEQO-UHFFFAOYSA-M Acetate Chemical compound CC([O-])=O QTBSBXVTEAMEQO-UHFFFAOYSA-M 0.000 description 2
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 239000000654 additive Substances 0.000 description 2
- 230000000996 additive effect Effects 0.000 description 2
- BYFGZMCJNACEKR-UHFFFAOYSA-N aluminium(i) oxide Chemical compound [Al]O[Al] BYFGZMCJNACEKR-UHFFFAOYSA-N 0.000 description 2
- QDOXWKRWXJOMAK-UHFFFAOYSA-N dichromium trioxide Chemical compound O=[Cr]O[Cr]=O QDOXWKRWXJOMAK-UHFFFAOYSA-N 0.000 description 2
- 238000010304 firing Methods 0.000 description 2
- PJXISJQVUVHSOJ-UHFFFAOYSA-N indium(III) oxide Inorganic materials [O-2].[O-2].[O-2].[In+3].[In+3] PJXISJQVUVHSOJ-UHFFFAOYSA-N 0.000 description 2
- 239000004570 mortar (masonry) Substances 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 229910020203 CeO Inorganic materials 0.000 description 1
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 1
- KOPBYBDAPCDYFK-UHFFFAOYSA-N Cs2O Inorganic materials [O-2].[Cs+].[Cs+] KOPBYBDAPCDYFK-UHFFFAOYSA-N 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- FUJCRWPEOMXPAD-UHFFFAOYSA-N Li2O Inorganic materials [Li+].[Li+].[O-2] FUJCRWPEOMXPAD-UHFFFAOYSA-N 0.000 description 1
- 229910019704 Nb2O Inorganic materials 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 1
- 150000001412 amines Chemical class 0.000 description 1
- 229910021529 ammonia Inorganic materials 0.000 description 1
- GHPGOEFPKIHBNM-UHFFFAOYSA-N antimony(3+);oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[Sb+3].[Sb+3] GHPGOEFPKIHBNM-UHFFFAOYSA-N 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- AKUNKIJLSDQFLS-UHFFFAOYSA-M dicesium;hydroxide Chemical compound [OH-].[Cs+].[Cs+] AKUNKIJLSDQFLS-UHFFFAOYSA-M 0.000 description 1
- XUCJHNOBJLKZNU-UHFFFAOYSA-M dilithium;hydroxide Chemical compound [Li+].[Li+].[OH-] XUCJHNOBJLKZNU-UHFFFAOYSA-M 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 238000005470 impregnation Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- GNRSAWUEBMWBQH-UHFFFAOYSA-N nickel(II) oxide Inorganic materials [Ni]=O GNRSAWUEBMWBQH-UHFFFAOYSA-N 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 229910000108 silver(I,III) oxide Inorganic materials 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- IATRAKWUXMZMIY-UHFFFAOYSA-N strontium oxide Inorganic materials [O-2].[Sr+2] IATRAKWUXMZMIY-UHFFFAOYSA-N 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
Abstract
Description
【０００１】0001
【産業上の利用分野】本発明はＨ２Ｓ（硫化水素ガス）
の検出に優れたガスセンサに関する。[Industrial Application Field] The present invention uses H2S (hydrogen sulfide gas)
This invention relates to a gas sensor that is excellent in detecting gas.
【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。[Prior Art] Semiconductor gas sensors, which detect the presence or absence of gas by connecting electrodes to a metal oxide semiconductor whose resistance value changes due to adsorption and desorption of gas, have been used as gas leak alarms to measure the resistance value. It is used as such.
【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、硫化水素
、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, there has recently been a demand for the development of a gas sensor for autoventilating rooms such as toilets and kitchens in residences. In other words,
The main odor components in toilets, kitchens, etc. are hydrogen sulfide, ammonia, amines, and mercaptans, and to maintain a comfortable living environment, the concentration of these gases must be kept at several ppb.
A sensor that can detect in the range of ~ several ppm is required. However, the detectable concentration using conventional metal oxide semiconductor gas sensors is several hundred ppm or more.
【０００４】そこで、特開昭５８−７９１４９号及び特
開昭６３−３１３０４８号には、金属酸化物半導体とし
てのＳｎＯ２に更に別の金属（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-58-79149 and JP-A-63-313048, another metal (usually in the form of an oxide) is added to SnO2 as a metal oxide semiconductor. , proposals have been made to increase gas detection sensitivity.
【０００５】ここで、特開昭５８−７９１４９号には添
加金属酸化物として、Ｓｂ２Ｏ３、ＴｉＯ２、Ａｌ２Ｏ
３、Ｌｉ２Ｏ及びＣｒ２Ｏ３が、特開昭６３−３１３０
４８号には添加金属酸化物として、ＰｂＯ、ＰｄＯ及び
ＺｎＯがそれぞれ開示されている。Here, in JP-A-58-79149, as additive metal oxides, Sb2O3, TiO2, Al2O
3. Li2O and Cr2O3 are disclosed in JP-A-63-3130
No. 48 discloses PbO, PdO, and ZnO as additive metal oxides.
【０００６】[0006]
【発明が解決しようとする課題】図６はＳｎＯ２からな
るガスセンサの応答曲線を示すグラフであり、縦軸はガ
ス感度の逆数を対数目盛で表示している。これより２０
０℃及び３００℃の応答曲線を見ると、ガス感度は比較
的良好であるが雰囲気をＨ２Ｓから空気に切り替えた時
の回復応答性が悪いことが分る。一方センサ温度を４０
０℃まで高めれば回復応答性は良くなるが、図７及び（
表１）にも示すようにＳｎＯ２及びＩｎ２Ｏ３は急激に
ガス感度が低下する。尚、図７中、低温側の素子温度で
ガス感度の表示のないものは素子抵抗が測定限界である
ことを示す。FIG. 6 is a graph showing the response curve of a gas sensor made of SnO2, in which the vertical axis represents the reciprocal of gas sensitivity on a logarithmic scale. 20 from this
Looking at the response curves at 0°C and 300°C, it can be seen that the gas sensitivity is relatively good, but the recovery response when the atmosphere is switched from H2S to air is poor. Meanwhile, set the sensor temperature to 40
If the temperature is raised to 0°C, the recovery response improves, but as shown in Figures 7 and (
As shown in Table 1), the gas sensitivity of SnO2 and In2O3 decreases rapidly. Note that in FIG. 7, when the element temperature is on the low temperature side and no gas sensitivity is displayed, the element resistance is at the measurement limit.
【０００７】[0007]
【表１】[Table 1]
【０００８】[0008]
【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、ガスセンサを構成する金属酸化物半導体として
、Ｎｂ２Ｏ５またはアナターゼ型のＴｉＯ２とした。[Means for Solving the Problems] In order to solve the above problems, the present invention uses Nb2O5 or anatase-type TiO2 as a metal oxide semiconductor constituting a gas sensor.
【０００９】[0009]
【作用】ガスセンサを構成する金属酸化物半導体として
Ｎｂ２Ｏ５またはアナターゼ型のＴｉＯ２を選定するこ
とで、Ｈ２Ｓに対する応答速度とガス感度に優れたガス
センサが得られる。[Operation] By selecting Nb2O5 or anatase-type TiO2 as the metal oxide semiconductor constituting the gas sensor, a gas sensor with excellent response speed to H2S and gas sensitivity can be obtained.
【００１０】0010
【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及び図２は本発明に係るガスセ
ンサの一例を示す斜視図である。DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described below with reference to the accompanying drawings. Here, FIGS. 1 and 2 are perspective views showing an example of a gas sensor according to the present invention.
【００１１】図１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４を同じく
焼成によりアルミナ基板２表面に形成している。尚、ア
ルミナ等の基板に金属酸化物半導体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に直接電極を埋設
してもよい。また図２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Ｐ
ｔ線１３，１３を包むように金属酸化物半導体１４の層
を形成している。ここで、金属酸化物半導体４は多孔質
焼結体となっている。A gas sensor 1 shown in FIG. 1 has an alumina substrate 2.
A pair of comb-shaped Au electrodes 3, 3 are formed by firing, and a metal oxide semiconductor 4 to which these Au electrodes 3, 3 are connected is also formed on the surface of the alumina substrate 2 by firing. Note that, instead of forming the metal oxide semiconductor in the form of a thin film on a substrate such as alumina, the electrode may be directly buried in the metal oxide semiconductor having a certain thickness. Further, the gas sensor 11 shown in FIG. 2 has a pair of Pt wires 13, 13 wound around a cylindrical alumina tube 12.
A layer of metal oxide semiconductor 14 is formed so as to surround the t-lines 13, 13. Here, the metal oxide semiconductor 4 is a porous sintered body.
【００１２】ここで上記金属酸化物半導体４はＮｂ２Ｏ
５またはアナターゼ型のＴｉＯ２或いは必要に応じてこ
れらに特定の金属酸化物を添加したものとし、その製法
の一例を以下に述べる。尚、Ｎｂ２Ｏ５またはアナター
ゼ型のＴｉＯ２としては市販の高純度のものをそのまま
用い、また添加する金属酸化物は酢酸塩または硫酸塩の
形態のものを用い、添加量は酸化物換算で１〜１０重量
％、本実施例では５重量％とし、含浸法により行った。Here, the metal oxide semiconductor 4 is Nb2O
5 or anatase type TiO2, or a specific metal oxide added thereto as necessary, and an example of the manufacturing method will be described below. In addition, commercially available high-purity Nb2O5 or anatase-type TiO2 is used as is, and the metal oxide to be added is in the form of acetate or sulfate, and the amount added is 1 to 10% by weight in terms of oxide. %, and in this example, it was 5% by weight, and the impregnation method was used.
【００１３】先ず、各々の塩を純水に所定量溶解させた
後、純水に懸濁した高純度酸化物と混合し、ホットスタ
ーラで加熱攪拌する。次いで蒸発せしめて乾燥固化させ
た後、残った固形分を乾燥器中で乾燥させ、この粉末を
メノウ乳鉢で粉砕した後、６００℃で１時間加熱し、添
加した塩化物または酢酸塩を分解する。この粉末を再び
メノウ乳鉢で粉砕し、この粉末をビヒクルとともに混練
してペースト状にしてアルミナ基板上にプリントし、こ
の後６００℃〜９５０℃で焼成する。First, a predetermined amount of each salt is dissolved in pure water, then mixed with a high purity oxide suspended in pure water, and heated and stirred with a hot stirrer. After drying and solidifying by evaporation, the remaining solid content is dried in a dryer, and this powder is ground in an agate mortar and heated at 600°C for 1 hour to decompose the added chloride or acetate. . This powder is again ground in an agate mortar, kneaded with a vehicle to form a paste, printed on an alumina substrate, and then fired at 600°C to 950°C.
【００１４】図３乃至図５はそれぞれセンサ温度を４０
０℃とし、Ｈ２Ｓの濃度を５ｐｐｍとした場合のＮｂ２
Ｏ５ガスセンサ、ＢａＯ−ＴｉＯ２（Ａ）ガスセンサ及
びＣａＯ−ＴｉＯ２（Ａ）ガスセンサの応答曲線を示す
グラフである。尚、Ａはアナターゼ型、Ｒはリチル型で
あることを示す。また以下の（表２）は各種金属酸化物
を５重量％添加した場合のガス感度を示すものである。FIGS. 3 to 5 each show the sensor temperature at 40°C.
Nb2 when the temperature is 0°C and the concentration of H2S is 5 ppm
It is a graph which shows the response curve of an O5 gas sensor, a BaO-TiO2 (A) gas sensor, and a CaO-TiO2 (A) gas sensor. In addition, A indicates anatase type and R indicates lythyl type. Table 2 below shows the gas sensitivity when 5% by weight of various metal oxides were added.
【００１５】[0015]
【表２】[Table 2]
【００１６】[0016]
【発明の効果】図３、図７及び表１からはアナターゼ型
のＴｉＯ２及びＮｂ２Ｏ５単味でガスセンサを構成した
場合に、４００℃以上の高温でＨ２Ｓに対するガス感度
が高く、しかも雰囲気をＨ２Ｓから空気に切り替えた時
の回復が速いことが分る。また図４、図５及び表２から
Ｃｓ２Ｏ、ＺｎＯ、ＰｂＯ、ＢａＯ、ＣｕＯ、ＣａＯ、
ＣｅＯ、ＳｒＯ、ＮｉＯ、Ｉｎ２Ｏ３またはＡｇ２Ｏの
うちの少なくとも１種を適宜選択して添加することによ
り、ガス感度及び回復時間が更に向上することが分る。[Effects of the Invention] Figures 3, 7, and Table 1 show that when a gas sensor is composed of anatase-type TiO2 and Nb2O5 alone, the gas sensitivity to H2S is high at high temperatures of 400°C or higher, and the atmosphere is changed from H2S to air. It can be seen that recovery is fast when switching to Moreover, from FIG. 4, FIG. 5, and Table 2, Cs2O, ZnO, PbO, BaO, CuO, CaO,
It can be seen that the gas sensitivity and recovery time are further improved by appropriately selecting and adding at least one of CeO, SrO, NiO, In2O3, and Ag2O.
【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】本発明に係るガスセンサの一例を示す斜視図[
FIG. 2 is a perspective view showing an example of a gas sensor according to the present invention
【図
３】本発明に係るガスセンサの応答曲線を示すグラフ[Fig. 3] Graph showing the response curve of the gas sensor according to the present invention
【図４】本発明に係るガスセンサの応答曲線を示すグラ
フFIG. 4 is a graph showing the response curve of the gas sensor according to the present invention.
【図５】本発明に係るガスセンサの応答曲線を示すグラ
フFIG. 5 is a graph showing the response curve of the gas sensor according to the present invention.
【図６】従来のガスセンサの応答曲線を示すグラフ[Figure 6] Graph showing the response curve of a conventional gas sensor
【図
７】各種金属酸化物半導体のＨ２Ｓ感度と温度との関係
を示すグラフ[Figure 7] Graph showing the relationship between H2S sensitivity and temperature of various metal oxide semiconductors
１，１１…ガスセンサ、２，１２…アルミナ、３，１３
…電極、４，１４…金属酸化物半導体。1,11...Gas sensor, 2,12...Alumina, 3,13
...electrode, 4,14...metal oxide semiconductor.
Claims (1)
着による抵抗値の変化を利用したガスセンサにおいて、
前記金属酸化物半導体はＮｂ２Ｏ５またはアナターゼ型
のＴｉＯ２を用いたことを特徴とするガスセンサ。[Claim 1] A gas sensor that utilizes changes in resistance due to adsorption and desorption of gas to a metal oxide semiconductor,
A gas sensor characterized in that the metal oxide semiconductor is Nb2O5 or anatase-type TiO2.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13567891A JPH04335149A (en) | 1991-05-10 | 1991-05-10 | Gas sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13567891A JPH04335149A (en) | 1991-05-10 | 1991-05-10 | Gas sensor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH04335149A true JPH04335149A (en) | 1992-11-24 |
Family
ID=15157373
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP13567891A Withdrawn JPH04335149A (en) | 1991-05-10 | 1991-05-10 | Gas sensor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH04335149A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6672137B1 (en) * | 1999-10-27 | 2004-01-06 | Ngk Spark Plug Co., Ltd. | Oxygen sensor and manufacturing method of sensor element |
| CN109107358A (en) * | 2018-09-20 | 2019-01-01 | 国网河北省电力有限公司电力科学研究院 | A kind of cerium oxide/copper oxide hetero-junctions composite oxides and its preparation method and application |
-
1991
- 1991-05-10 JP JP13567891A patent/JPH04335149A/en not_active Withdrawn
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6672137B1 (en) * | 1999-10-27 | 2004-01-06 | Ngk Spark Plug Co., Ltd. | Oxygen sensor and manufacturing method of sensor element |
| US7254985B2 (en) | 1999-10-27 | 2007-08-14 | Ngk Spark Plug Co., Ltd. | Oxygen sensor and a manufacturing method of the sensor device |
| CN109107358A (en) * | 2018-09-20 | 2019-01-01 | 国网河北省电力有限公司电力科学研究院 | A kind of cerium oxide/copper oxide hetero-junctions composite oxides and its preparation method and application |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Ishihara et al. | Improved sensitivity of CuO BaTiO3 capacitive-type CO2 sensor by additives | |
| Maekawa et al. | Development of SnO2-based ethanol gas sensor | |
| Shimizu et al. | Improvement of SO2 sensing properties of WO3 by noble metal loading | |
| JPS6054259B2 (en) | Moisture sensitive ceramic | |
| EP0197629B1 (en) | Alcohol selective gas sensor | |
| EP0114310B1 (en) | Carbon monoxide sensing element and process for manufacturing it | |
| JPH0587760A (en) | Gas sensor and production thereof | |
| JP2921032B2 (en) | Ammonia gas sensor | |
| KR20190136437A (en) | Gas Detection Complex, Method for Manufacturing the Complex, Gas Sensor Including the Complex and Method for Manufacturing the Sensor | |
| Ishihara et al. | Capacitive-type gas sensor for the selective detection of carbon dioxide | |
| JPS6349181B2 (en) | ||
| JPH04335149A (en) | Gas sensor | |
| JP2921033B2 (en) | Hydrogen sulfide gas sensor | |
| JPS63298149A (en) | Thin film type ozone sensor | |
| JP3756156B2 (en) | Carbon dioxide sensor | |
| Ishihara et al. | Improvement of Sensing Characteristics of the Capacitive Type CO2 Sensor, CuO-BaTiO3, by Addition of Metal or Metal Oxide. | |
| JP2004239832A (en) | Carbon dioxide sensor | |
| JPS6344703A (en) | Moisture-sensitive device compound | |
| JP3527948B2 (en) | Sulfur oxide sensor | |
| Kajale et al. | Effect of Surface Modification on SrTiO^ sub 3^ Thick films: Room Temperature H^ sub 2^ S Gas Sensor | |
| JPH0551096B2 (en) | ||
| JP2005172630A (en) | Carbon dioxide sensor | |
| JPS5871446A (en) | Gas sensor for oxygen and carbon monoxide | |
| JPS608459B2 (en) | gas detection element | |
| JP2002031614A (en) | Nitrous oxide gas sensor |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A300 | Application deemed to be withdrawn because no request for examination was validly filed |
Free format text: JAPANESE INTERMEDIATE CODE: A300 Effective date: 19980806 |