JPS5822947A - Gas sensor using sno2 group - Google Patents

Gas sensor using sno2 group

Info

Publication number
JPS5822947A
JPS5822947A JP12068481A JP12068481A JPS5822947A JP S5822947 A JPS5822947 A JP S5822947A JP 12068481 A JP12068481 A JP 12068481A JP 12068481 A JP12068481 A JP 12068481A JP S5822947 A JPS5822947 A JP S5822947A
Authority
JP
Japan
Prior art keywords
gas
sensor
alcohol
sno2
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.)
Pending
Application number
JP12068481A
Other languages
Japanese (ja)
Inventor
Hozumi Nita
二田 穂積
Kaoru Ogino
薫 荻野
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.)
Yazaki Corp
Original Assignee
Yazaki Corp
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 Yazaki Corp filed Critical Yazaki Corp
Priority to JP12068481A priority Critical patent/JPS5822947A/en
Publication of JPS5822947A publication Critical patent/JPS5822947A/en
Pending legal-status Critical Current

Links

Classifications

    • GPHYSICS
    • G01MEASURING; TESTING
    • G01NINVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N27/00Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
    • G01N27/02Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance
    • G01N27/04Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance
    • G01N27/12Investigating 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

Landscapes

  • 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

PURPOSE:To prevent an incorrect alarm due to gaseous alcohol on a sensor of combustible gas such as town gas etc., by forming Co3O4-alpha-Al2O3 film on the contact surface of a gas sensor using SnO2 group with the gas to be inspected and reduces the sensitivity for gaseous alcohol. CONSTITUTION:In a detection element of combustible gas such as town gas, propane gas etc., Co3O4-alpha-Al2O3 film is formed on the surface of a gas sensor using SnO2 group and the sensitivity for alcohol vapor is reduced so as not to give an incorrect alarm by the alcohol vapor produced at the time of cooking. After the alpha-Al2O3 powder is immersed in a solution of Co(NO3)3, then taken up, dried and calcined and a paste is made by adding water to the said powder and applied on the surface of the sensor and is dried. Then, Co3O4-alpha-Al2O3 film is formed by calcining said sensor. In this manner, only gaseous alcohol is treated before reaching to the SnO2 layer and is made not to be perceived.

Description

【発明の詳細な説明】 本発明は改良した5no2系ガスセンサーに係わる。さ
らに詳述すれば、本発明は、5noz系ガスセンサーの
表面にCo3o4−α−A12o3のガス弁別フィルタ
層を形成することにより、アルコールガスに対する感度
のみを低下せしめた5no2系ガスセンサーに係わる。
DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improved 5no2 gas sensor. More specifically, the present invention relates to a 5no2 gas sensor in which only the sensitivity to alcohol gas is reduced by forming a Co3o4-α-A12o3 gas discrimination filter layer on the surface of the 5noz gas sensor.

都市ガス用ガス警報器で使用されるガスセンサーでは、
天然ガス系のCH,、製造ガス系のH2およびブタンエ
アー系(LPG)のイン−c4H1゜の3種の被検ガス
について、爆発下限界(LEL)以下のできるだけ高感
度でバランスよく検知できることが理想である。
Gas sensors used in gas alarms for city gas,
Ideally, it would be possible to detect three types of gases: natural gas CH, manufactured gas H2, and butane air (LPG) IN-C4H1°, with as high a sensitivity as possible and in a well-balanced manner below the lower explosive limit (LEL). It is.

一般に、都市ガス用警報器の使用にあたっては、厨房の
天井附近か壁面上部に設置されるため、温度、湿度、雑
ガスなどの影響を受は易く、ガスセンサーの正常な作動
に関して環境が良いとは伝えない。
Generally, when using a city gas alarm, it is installed near the ceiling or on the top of the wall in the kitchen, so it is easily affected by temperature, humidity, miscellaneous gas, etc., and the environment must be favorable for the normal operation of the gas sensor. I can't tell you.

現在、凡用されている半導体ガスセンサーは、調理の際
使用される酒類から発生するアルコールガスに対しても
応答する性質をもつため、誤った警報を発する原因にな
っている。
Semiconductor gas sensors, which are commonly used at present, have the property of responding to alcohol gas emitted from alcoholic beverages used during cooking, which causes false alarms to be issued.

このようなアルコールの影響を回避し、理想的なガスセ
ンサーに改良するための方法として、各種の試みがなさ
れている。その1つの方法としては、半導体ガスセンサ
ーの材質の面からの改良である。しかしながら、この方
法では性能のバランスの面で困難なてとか多い。他の方
法としては、センサー表面を触媒的性能をもつフィルタ
ー材で覆い、特定なガスを感知しないようにするガス弁
別性を改良する方法がある。
Various attempts have been made to avoid such effects of alcohol and to improve the gas sensor into an ideal gas sensor. One method is to improve the material of the semiconductor gas sensor. However, there are many difficulties with this method in terms of performance balance. Another method is to improve gas discrimination by covering the sensor surface with a filter material that has catalytic properties to prevent detection of specific gases.

ところで、ガス警報器のガスセンサーとして最も多く使
用されているsn 02を主体とするガスセンサーも、
前述の如(、都市ガス、 LPGの成分でないアルコー
ルガスに対するある程度の感度を有している欠点があり
、しかも使用経年変化として、この感度が徐々に高感度
化して(る傾向があり、誤報の原因となっている。
By the way, gas sensors mainly based on sn 02, which is the most commonly used gas sensor for gas alarms, also
As mentioned above, they have the disadvantage of being sensitive to a certain degree to alcohol gas, which is not a component of city gas or LPG, and furthermore, as they age, this sensitivity tends to gradually increase, leading to false alarms. It is the cause.

この対策の1つとして、SnO□系ガスセンサーの表面
上に、金属酸化物および貴金属触媒などのガスフィルタ
ーを設けることが試みられているが、アルコールガスの
みを完全に弁別し、他の被検ガスに影響を与えないよう
にすることは困難であり、たとえばH2ガスも同時に弁
別されたり、また被検ガスの電圧特性の変化が大きくな
ることもある。
As one of the countermeasures against this problem, attempts have been made to provide a gas filter made of metal oxides and noble metal catalysts on the surface of the SnO□-based gas sensor. It is difficult to avoid affecting the gases; for example, H2 gas may also be discriminated at the same time, or the voltage characteristics of the gas to be detected may change significantly.

本発明は、このような欠点を解消し、不必要なアルコー
ルガスのみを完全に弁別できるようにしたSnO2系ガ
スセンサーを提供することを目的とする。
SUMMARY OF THE INVENTION An object of the present invention is to provide a SnO2-based gas sensor that can eliminate such drawbacks and completely discriminate only unnecessary alcohol gas.

したがって、本発明の目的は、5(102系ガスセンサ
ーの被検ガスと接触する面をCO3O4−α−A120
3  で塗膜してアルコールガスに対する感度を低下さ
せたことを特徴とする。  51102系ガスセンサー
を提供することにある。
Therefore, it is an object of the present invention to convert the surface of the 5 (102 series gas sensor that comes into contact with the gas to be detected) into CO3O4-α-A120.
3 to reduce sensitivity to alcohol gas. An object of the present invention is to provide a 51102 series gas sensor.

本発明の方法によれば、5n02系ガスセンサーの表面
上へのCo304−α−A1203膜の形成は次の如く
して行なう。
According to the method of the present invention, a Co304-α-A1203 film is formed on the surface of a 5n02 gas sensor as follows.

硝酸コバルト水溶液に微粉末状のα−A/zoaを浸漬
して含浸せしめ、最高750℃前後まで温度を上昇させ
て焼成し、Co ao4−α−A1203とする。
Finely powdered α-A/zoa is immersed in a cobalt nitrate aqueous solution to impregnate it, and then fired at a temperature of up to around 750°C to obtain Co ao4-α-A1203.

コレラアルコールガス弁別フィルタ材として使用する。Used as cholera alcohol gas discrimination filter material.

Co3O4/α−klho3の混合比は、塗布するセン
サーの特性に基いで決定されるが、Co3O4の量が5
〜30%(重量)となることが好ましい。
The mixing ratio of Co3O4/α-klho3 is determined based on the characteristics of the sensor to be coated, but if the amount of Co3O4 is 5
It is preferably 30% (by weight).

このようにして調製したフィルタ材にアルミナ系の結合
剤を少量加え、これに水を加えてペーストとする。次に
各種の方法により、このペーストをS。02系ガスセン
サーの表面に塗布し、自然乾燥する。乾燥後、約500
℃で加熱焼成する。
A small amount of alumina-based binder is added to the filter material thus prepared, and water is added to this to form a paste. Next, this paste is made into S by various methods. Apply it to the surface of the 02 series gas sensor and let it dry naturally. After drying, about 500
Heat and bake at ℃.

このガス弁別フィルタ膜の膜厚は所望の効果に応じて任
意に決定されるが、一般には約Oa51mである。
The thickness of this gas discrimination filter membrane is arbitrarily determined depending on the desired effect, but is generally approximately Oa51m.

このようにして調製された8102系ガスセンサーは、
被検ガスに対しては、従来のガス弁別フィルタをもたな
いSyl 02系ガスセンサーと全く同じ挙動を示すが
、誤った警報の原因となるアルコールガスに対してはC
O304−α−A/20gガス弁別フィルタの作用によ
り感度が低下されている。
The 8102 series gas sensor prepared in this way is
It behaves exactly the same as the Syl 02 series gas sensor, which does not have a conventional gas discrimination filter, with respect to the test gas, but with respect to alcohol gas, which can cause false alarms, C
The sensitivity is reduced by the action of the O304-α-A/20g gas discrimination filter.

Co304−α−A/20gフィルタの作用は、CO3
O4がアルコールガスに対して触媒作用を発揮し、00
304  表面でアルコールを処理してガス感知部まで
到達させないことにあり、したかって、現象的にはSm
og系ガスセンサーのアルコールガスに対する感度の低
下となって現われる。また、他の被検ガス、H2、CH
イC1H1oに対してはCO3O4の触媒作用がきわめ
て小さいため、感度の低下には至らないものと考えられ
る。
The action of Co304-α-A/20g filter is CO3
O4 exerts a catalytic effect on alcohol gas, and 00
304 The reason is that the alcohol is treated on the surface to prevent it from reaching the gas sensing part, so the phenomenon is that Sm
This appears as a decrease in the sensitivity of the OG gas sensor to alcohol gas. In addition, other test gases, H2, CH
Since the catalytic effect of CO3O4 on aiC1H1o is extremely small, it is thought that this does not lead to a decrease in sensitivity.

本発明の好適な具体例を参照して、本発明についてさら
に詳述する。
The present invention will be described in further detail with reference to preferred embodiments of the present invention.

のち、温度約750℃で焼成して、最終混合比Co3O
4/ (1−k120s = 3/7のCO304−α
−A1203でなるガス弁別フィルタ材を調製した。こ
れをアルミナ系結合剤とともに水で混練してペーストと
し、自己発熱型5noz系ガスセンサーの表面に塗布し
た。その後、自然乾燥し焼成した。
Afterwards, it is fired at a temperature of about 750°C to obtain a final mixing ratio of Co3O.
4/ (1-k120s = 3/7 CO304-α
-A gas discrimination filter material made of A1203 was prepared. This was kneaded with water together with an alumina binder to form a paste, which was applied to the surface of a self-heating type 5noz gas sensor. Then, it was naturally dried and fired.

得られたガスフィルタ式8102系センサーの特性を第
1図に示す。
The characteristics of the gas filter type 8102 sensor obtained are shown in FIG.

このような特性を有するガスセンサーを使用して都市ガ
ス警報器を作成する際には、H2、CH4、C4H1O
の警報濃度を0.1−〜0.3チの範囲に設定でき、こ
れに対してアルコールガスについては1チでも警報しな
いものとすることができる。
When creating a city gas alarm using a gas sensor with such characteristics, H2, CH4, C4H1O
The alarm concentration for alcohol gas can be set in the range of 0.1 to 0.3, whereas the alarm concentration for alcohol gas can be set so as not to alarm even at 1.

さらに、このガスフィルタ式5n02系センサーの経時
特性を第2図に示す。H2、CH4、C4H□0および
アルコールについていずれもほぼ変化がなく、しかも他
の性能についてはガスフィルタをもたない5n02単味
の場合と同じである。
Furthermore, the aging characteristics of this gas filter type 5n02 sensor are shown in FIG. There is almost no change in H2, CH4, C4H□0, and alcohol, and other performances are the same as in the case of 5n02 monomer without a gas filter.

以上本発明をその具体例について詳述したが、本発明は
この特定の実施例に限定されるものではなく、本発明の
精神を逸脱しないで幾多の変化変形がなし得ることはも
ちろんである。
Although the present invention has been described above in detail with reference to specific examples, the present invention is not limited to these specific examples, and it goes without saying that many changes and modifications can be made without departing from the spirit of the invention.

【図面の簡単な説明】[Brief explanation of the drawing]

第1図は本発明によるガスフィルタ式5(102系ガス
センラ葛各ガスに対する特性を示すグラフであり、 第
2図はこのガスセンサーの経時特性を示すグラフである
。 第1図 が7−1覆(X)
Fig. 1 is a graph showing the characteristics of the gas filter type 5 (102 series gas sensor) according to the present invention for each gas, and Fig. 2 is a graph showing the temporal characteristics of this gas sensor. (X)

Claims (1)

【特許請求の範囲】[Claims] 800x系ガスセンサーの被検ガスと接触する面をCo
 304−α−”’20Bで塗膜してアルコールガスに
対する感度を低下させたことを特徴とする、5n02系
ガスセンサー。
The surface of the 800x gas sensor that comes into contact with the test gas is
A 5n02-based gas sensor characterized in that it is coated with 304-α-''20B to reduce its sensitivity to alcohol gas.
JP12068481A 1981-08-03 1981-08-03 Gas sensor using sno2 group Pending JPS5822947A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP12068481A JPS5822947A (en) 1981-08-03 1981-08-03 Gas sensor using sno2 group

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP12068481A JPS5822947A (en) 1981-08-03 1981-08-03 Gas sensor using sno2 group

Publications (1)

Publication Number Publication Date
JPS5822947A true JPS5822947A (en) 1983-02-10

Family

ID=14792385

Family Applications (1)

Application Number Title Priority Date Filing Date
JP12068481A Pending JPS5822947A (en) 1981-08-03 1981-08-03 Gas sensor using sno2 group

Country Status (1)

Country Link
JP (1) JPS5822947A (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59126015U (en) * 1983-02-16 1984-08-24 株式会社不動テクニカル Formwork for concrete floor slabs
JPS59126014U (en) * 1983-02-16 1984-08-24 株式会社不動テクニカル Formwork for concrete floor slabs
JPS6165151A (en) * 1984-09-07 1986-04-03 Shinkosumosu Denki Kk Gas detecting element
DE3604594A1 (en) * 1986-02-14 1987-08-20 Schott Glaswerke Thin-film gas sensors having high measuring sensitivity as multilayer systems based on dipped indium oxide layers for detection of gas traces in carrier gases
JPH0493499U (en) * 1990-12-21 1992-08-13
KR100767347B1 (en) 2005-07-29 2007-10-17 최우성 P-type Co3O4-SnO2 composite having superior selectivity to CO over H2, and thick film and gas sensor prepared therefrom

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59126015U (en) * 1983-02-16 1984-08-24 株式会社不動テクニカル Formwork for concrete floor slabs
JPS59126014U (en) * 1983-02-16 1984-08-24 株式会社不動テクニカル Formwork for concrete floor slabs
JPS6165151A (en) * 1984-09-07 1986-04-03 Shinkosumosu Denki Kk Gas detecting element
JPH053897B2 (en) * 1984-09-07 1993-01-18 New Cosmos Electric Co
DE3604594A1 (en) * 1986-02-14 1987-08-20 Schott Glaswerke Thin-film gas sensors having high measuring sensitivity as multilayer systems based on dipped indium oxide layers for detection of gas traces in carrier gases
JPH0493499U (en) * 1990-12-21 1992-08-13
KR100767347B1 (en) 2005-07-29 2007-10-17 최우성 P-type Co3O4-SnO2 composite having superior selectivity to CO over H2, and thick film and gas sensor prepared therefrom

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