第7回 化学センサ研究発表会


September 25-26, 1988
Saitama University


プログラム


1
MediatorにHexacyanoferrate(III)を用いたディスポーザブルグルコースセンサ

南海史朗・河栗真理子・藤田真由美・飯島孝志

松下電器中研

DISPOSABLE GLUCOSE SENSOR USING HEXACYANOFERRATE (III) AS A MEDIATOR

Shiro NANKAI, Mariko KAWAGURI, Mayumi FUJITA and Takashi IIJIMA

Central Research Laboratories, Matsushita Electric Co., Ltd.
Moriguchi, Osaka 570, Japan

A disposable glucose sensor using hexacyanoferrate (III) (potassium ferricyanide) as a mediator was investigated. An enzyme reaction layer including mediator and water-soluble polymer was prepared on a carbon electrode produced by screen printing. A glucose concentration in whole blood was determined up to approximately 500 mg/dl without resorting to any procedures such dilution of a sample and stirring, and a coefficient of variation of 5% or lower was obtained. This sensor exhibited good storage characteristics at 35℃ on drying and the decrease in sensor response was as small as about 1%.


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2
メディエイター型グルコースセンサの応答解析

横山憲二*・早出広司**・民谷栄一* **・飴山 貫***・軽部征夫* **

東工大資源研*・東大先端研**・山口大農***

NUMERICAL ANALYSIS FOR THE RESPONSES OF THE MEDIATED GLUCOSE SENSOR

Kenji YOKOYAMA*, Koji SODE**, Eiichi YAMIYA* **, Minoru AMEYAMA*** and Isao KARUBE* **

*Research Laboratory of Resources Utilization, Tokyo Institute of Technology
4259 Nagatsuta-cho Midori-ku, Yokohama 227, Japan
**Research Center for Advanced Science and Technology, University of Tokyo
4-6-1 Komaba Meguro-ku, Tokyo 153, Japan
***Department of Agricultural Chemistry, Faculty of Agriculture, Yamaguchi University
Yamaguchi 753, Japan

A theoretical discussion based on enzyme electrode kinetics was carried out. Steady-state responses were calculated in the presence of mediators uniformly distributed in the bulk solution. In the case of excessive mediator concentration, the larger σs (ratio of the enzyme reaction rate to the substrate diffusion rate) was, the higher normalized response was obtained. In the case of excessive substrate concentration, the larger σM was, the higher response was indicated similarly. In addition, the normalized response has a good relationship with experimental data.


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3
有機複合膜を用いる新しいアンペロメトリックグルコースセンサ

水沼昌也・大坂武男・小山 昇・禿 康子*・中村節子*

東京農工大工・日本女子大*

AMPEROMETRIC GLUCOSE SENSOR USING ORGANIC COMPOSITE FILMS

Masaya MIZUNUMA, Takeo OHSAKA, Noboru OYAMA, Yasuko KAMURO* and Sadako NAKAMURA*

Department of Applied Chemistry for Resources, Tokyo University of Agriculture and Technology
Koganei, Tokyo 184, Japan
*Department of Chemistry, Japan Women's University
Bunkyo-ku, Tokyo 112, Japan

The electrode characteristics of the immobilized enzyme chemically modified electrode (IECME) based on bilayer-film coating for amperometric determination of glucose were examined. The electrode substrate was coated with two kinds of polymeric films in a bilayer state, that is, at first with cobalt tetra (ο-aminophenyl) porphyrin polymer (poly-CoTAPP) film, prepared by electro-oxidative polymerization of the monomer and then with the enzyme film consisting of bovine serum albumin and glucose oxidase that were held together by cross-linking with gultaraldehyde. In this sensor system for estimation of glucose concentration, O2 depletion was monitored by measuring the current for O2 reduction electrocatalyzed by the poly-CoTAPP film. It was found that by measuring the O2 reduction current obtained at the IECME based on the bilayer-film coating one can evaluate the concentration of glucose in solution.


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4
半導体技術を利用したアンペロメトリック型バイオセンサ

鈴木博章・小嶋尚美・菅間明夫・武井文雄・池上佳住・民谷栄一* **・軽部征夫* **

富士通研・東工大資源研*・東大先端研**

AMPEROMETRIC BIOSENSORS FABRICATED USING SEMICONDUCTOR TECHNOLOGY

Hiroaki SUZUKI, Naomi KOJIMA, Akio SUGAMA, Fumio TAKEI,Kasumi IKEGAMI, Eiichi TAMMIYA* ** and Isao KARUBE* **

FUJITSU LABORATORIES, LTD.,
Atsugi-shi, Kanagawa 243-01, Japan
*Research Center for Advanced Science and Technology, University of Tokyo
Meguro-ku, Tokyo 153, Japan
**Research Laboratory of Resources Utilization, Tokyo Institute of Technology
Yokohama, Kanagawa 227, Japan

An amperometric carbon dioxide (CO2) sensor was developed using a CO2-utilizing autotrophic bacterium (S-17) and the Clark-type micro-oxygen electrode. The bacterium was immobilized in a calcium alginate gel, which was covered with a gas-permeable membrane. The 90% response time was 2-3 min. A linear calibration curve was obtained for NaHCO3 concentrations between 0.5 mM and 3.5 mM at 30℃.


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5
酵素重合法によるバイオセンサのマイクロファブリケーション

相澤益男・王 麗莉・篠原寛明・碇山義人

東工大工

MICROFABRICATION OF BIOSENSORS BY ENZYMATIC POLYMERIZATION

Masuo AIZAWA, LiLi WANG, Hiroaki SHINOHARA and Yoshihito IKARIYAMA

Department of Bioengineering, Tokyo Institute of Technology
Ookayama Meguro-ku, Tokyo 152, Japan

An enzymatic polymerization process ahs been developed to fabricate micro-biosensors. Bilirubin oxidase (BOD), which was found to catalyze polymerization of aniline, was adsorbed on the sensor base surface and contacted with an aniline solution. A BOD entrapped polyaniline thin membrane was formed on the site. An micro-enzyme sensor was fabricated by the enzymatic polymerization process.


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6
金黒を用いる微少酵素電極とその基本特性

片山明秀**・碇山義人*・山内 繁・矢尾板仁・吉田泰彦**・島田直樹**・行足智明***

国立リハビリ研・東工大工*・東洋大工**・住友セメント中研***

FABRICATION AND CHARACTERIZATION OF GOLD-BLACK MICRO ENZYME ELECTRODE

Akihide KATAYAMA**, Yoshihito IKARIYAMA*, Shigeru YAMAUCHI, Masashi YAOITA, Yasuhiko YOSHIDA**, Naoki SHIMADA** and Tomoaki YUKIASHI***

Research Institute of National Rehabilitation Center
4-1 Namiki Tokorozawa, Saitama 359, Japan
*Dept. of Bioengineering, Tokyo Institute of Technology
2-12-1 O-okayama Meguro-ku, Tokyo 152, Japan
**Dept. of Applied Chemistry, Faculty of Engineering, Toyo University
2100 Kujirai, Kawagoe, Saitama 350, Japan
***Central Research Laboratory, Sumitomo Cement Co., Ltd.
5-8-5 Toyotomi Funabashi, Chiba 274, Japan

We have already reported a new micro biosensing device, in which enzyme is immobilized on platinum black surface. In order to demonstrate that the electrode material is not limited to platinum, we have used gold black electrolytically deposited on gold wire of 50 μm diameter as substrate of immobilization of GOD.
Potentiostatic anodic current of hydrogen peroxide oxidation showed a good linear dependence upon glucose concentration in phosphate buffer solution from 10 μM to 10 mM, although the oxidation current is smaller than that observed on the platinum black substrate.
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7
ポーラロ方式酵素センサのアノード分極処理による選択性の向上

行足智明・潮田博夫・矢尾板仁*・山内 繁*・碇山義人**

住友セメント中研・国立リハビリ研*・東工大工**

ANODIC POLARIZATION FOR THE SURFACE CONTROL OF PLATINIZED PLATINUM AS A TRANSDUCER MATRIX FOR MICRO-ENZYME SENSOR

Tomoaki YUKIASHI, Hiroo USHIODA, Masashi YAOITA*, Shigeru YAMAUCHI* and Yoshihito IKARIYAMA**

Central Research Laboratory, Sumitomo Cement Co., Ltd.
5-8-5 Toyotomi Funabashi, Chiba 359, Japan
*Research Institute, National Rehabilitation Center
4-1 Namiki Tokorozawa, Saitama 359, Japan
**Department of Bioengineering, Tokyo Institute of Technology
Ookayama Meguro, Tokyo 152, Japan

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8
微少酵素電極による植物中の糖のin vivo測定

村上 隆・竹川征弘・松岡英明

東京農工大工

in vivo DETERMINATION OF SUGAR IN PLANT WITH MICROENZYME ELECTRODE

Takashi MURAKAMI, Yukihiro TAKEKAWA and Hideaki MATSUOKA

Department of Industrial Chemistry, Faculty of Technology, Tokyo University of Agriculture and Technology
2-24-16 Nakamachi Koganei, Tokyo 184, Japan

A dual type microelectrode was developed for the in vivo measurement of sugar in plant stem. Initially Safranin T was injected into the stem from one of the two capillaries. Then microscopic observation and VTR recording were performed for its cross sections. A potential profile along the depth was also measured to detect the electrode tip position. Microenzyme electrodes for sucrose and glucose were prepared. Glucose could be measured was one type of electrode, which was prepared by immobilizing glucose oxidase on the surface of a capillary tip. Sucrose could be detected with another type of enzyme electrode, which was prepared by immobilizing three enzymes (glucose oxidase, invertase, mutarotase) in calcium alginate gel matrix.


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9
固体電解質(フッ化ランタン)センサのグルコースセンサへの適用

又吉直子・三浦則雄・山添 昇

九大総合理工

APPLICATION OF SOLID ELECTROLYTE (LaF3) SENSOR TO GLUCOSE SENSOR

Naoko MATAYOSHI, Norio MIURA and Noboru YAMAZOE

Department of Materials Science and Technology, Graduate School of Engineering Science, Kyushu University
Kasuga-shi, Fukuoka 816, Japan

A new type of solid-state biosensor using LaF3 solid electrolyte was developed for detecting glucose. The sensor element was composed of the following electrochemical cell: (reference electrode) Sn, SnF2 | LaF3 | Pt-GOD (sensing electrode). Glucose oxidase was incorporated into an electrochemically deposited porous platinum black electrode. The e.m.f. of the sensor cell was found to vary logarithmically with a change in glucose concentration in the range from 1×10-5 to 1×10-2 M in a phosphate buffer solution of pH 7.0, following Nernst's equation. The 90% response time to 3×10-2 M glucose was about 15 s at 30℃. The sensitivity of the sensor to glucose was almost stable for about 30 days.


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10
酸化チタン酸素電極を用いたグルコースセンサの特性

木村正美・池田章一郎・伊藤 要・大倉國利*・中尾昭公*・高木 弘*・近藤達平*

名工大・名大医*

DEVELOPMENT OF A NEEDLE-TYPE GLUCOSE SENSOR BASED ON TITANIUM DIOXIDE OXYGEN ELECTRODES

Shoichiro IKEDA, Masami KIMURA, Kaname ITO, Kunitoshi OHKURA*, Akimasa NAKAO*, Hiroshi TAKAGI* and Tatsuhei KONDO*

Department of Applied Chemistry, Nagoya Institute of Technology
Gokiso-cho Showa-ku, Nagaya 466, Japan
*Second Department of Surgery, Nagoya University School of Medicine
65 Tsurumai-cho Showa-ku, Nagoya 466, Japan

A new needle-type glucose sensor has been developed using an oxygen electrode based on a new concept which is composed of a Ti wire whose surface was anodically oxidized to form a thin oxide layer, and works well as an oxygen sensor with an applied potential of -0.8 V vs. a Ag/AgCl reference/counter electrode. Glucose oxidase was immobilized on the oxide layer treated with 3-aminopropyltriethoxysilane using glutaraldehyde and bovine serum albumin. Several surface analyses were employed to investigate the surface characteristics of the sensor. This sensor responds glucose up to 30 mg/dl without a semipermeable membrane. By 5 times dip-coating of cellulose acetate, the sensor responds up to 700 mg/dl. In vivo test using a normal dog, the sensor responds the blood glucose levels, although improvements in the response time and stability are still required.


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11
I S F E T型バイオセンサを用いたヒトの経皮的血糖値連続測定

伊藤成史・木村 純・斉藤 敦・栗山敏秀・兼吉昭雄・菊池 眞*・荒井恒憲*・根岸直樹*・萱嶋信介*

日本電気・防衛医大*

AN ISFET BIOSENSOR APPLICATION TO NON-INVASIVE MONITORING OF GLUCOSE CONCENTRATION IN HUMAN

Narushi ITO, Jun KIMURA, Atsushi SAITO, Toshihide KURIYAMA, Akio KANEYOSHI, Makoto KIKUCHI*, Tsunenori ARAI*, Naoki NEGISHI*, Shinsuke KAYASHIMA*

NEC Corporation
Kawasaki, Kanagawa 213, Japan
*National Defense Medical College Tokorozawa, Saitama 359, Japan

Quasi continuous human blood glucose monitoring has been achieved by applying an ISFET biosensor to transcutaneous effusion fluid. The effusion fluid, collected through the skin by evacuation without harm, contains the same glucose and urea concentration as that in the serum1). The main advantage of using the ISFET biosensoris its application to small volume samples; for example, only about 0.4 ul/min effusion fluid, under 400 torr suction, is extracted from 1 cm skin surface in human experiment. Glucose concentration for every 5 ul/10min sampling fluid were emeasued by the ISFET biosensor. By 75 g oral glucose torerance test, an artificial high glucose concentration was induced. A good correlation between effusion fluid glucose concentration and blood glucose concentration was obtained by an ISFET biosensor.


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特別講演1
半導体バイオセンサとその開発動向

綾木和雄

日本電気

ISFET BIOSENSORS AND THEIR DEVELOPMENT TREND

Kazuo AYAKI

NEC Corporation
Kawasaki-shi, Kanagawa 213, Japan

Ion sensitive field effect transistors (ISFETs) capable of measuring ion concentration in solution have recently drawn much attention, as biosensor transducers. Since the ISFET is manufactured by an IC (integrated circuit) technology, it has several advantages over the conventional ion-selective electrodes, including the following; mass prodection, small size, low cost, multifunction, electric circuit integration. In this article, their features, performance, applications and future trend are described.


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12
シリコン基板上に集積化したマイクロポンプによる微量液体制御システム

庄子習一・江刺正喜

東北大工

A MICROLIQUID FLOW CONTROL SYSTEM USING A MICRO-PUMP INTEGRATED ON A SILICON WAFER

Shuichi SHOJI and Masayoshi ESASHI

Department of Electronic Engineering, Faculty of Engineering, Tohoku University
Aoba Aramaki, Sendai 980, Japan

A new type micro-pump for a micro liquid flow control system is developped. The pump is a diaphragm type pump, formed on a silicon substrate, using two one-way micro-valve and a piezoelectric actuator. Very small flow of the order of μl/min can be controlled accurately with this pump. In order to achieve more precise control of liquid flow, a protopype of a micro liquid flow sensor, made on a silicon wafer, for monitoring the output flow of the micro pump is also fabricated.


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13
ゲル状電解質を用いたL B膜免疫センサ

内田秀和・原 正史・勝部昭明

埼玉大工

LB FILM IMMUNO-SENSOR WITH A SEMI-SOLID GEL ELECTROLYTE

Hidekazu UCHIDA, Masashi HARA and Teruaki KATSUBE

Department of Electronics, Saitama University
Shimo-Okubo, Urawa 338, Japan

A semi-solid electrolyte was applied to construct a high sensitive immuno-sensor of a potentiometric detection type. A thin film ager gel was used as the semi-solid electrolyte for the detection of surface potential variation of an IgG sensor which was composed of IgG antigen electrolyte and high sensitive semiconductor amplifier. The antigen was immobilized with a LB technique.
It was shown that a semi-solid electrolyte makes it possible to enhance the output response as well as to improve the noise level. The optimum conditions to achieve a high signal to noise ratio and the mechanism of sensitivity improvement were also discussed.


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14
アポ酵素センサを用いる銅イオンの微量計測

佐藤生男・五井直人・青木保之

神奈川工科大学

MICROANALYSIS FOR COPPER(II) IONS USING AN APOENZYME SENSOR

Ikuo SATOH, Naoto GOI and Yasuyuki AOKI

Department of Chemical Technology, Faculty of Engineering, Kanagawa Institute of Technology
1030 Shimo-Ogino, Atsugi-shi, Kanagawa 243-02, Japan

A novel electrochemical biosensing with use of an apoenzyme sensor is proposed for microdetermination of copper(II) ions. The biosensing system was assembled with the immobilized galactose oxidase reactor and a flow-through oxygen electrode. Copper(II) ions were amperometrically determined in the range from 1 μM to 10 mM through its activation of the immobilized metal-free enzyme (apoenzyme) reactor. The activity was assessed by injecting 40 mM D-galactose solution and then the consumption of dissolved oxygen by the oxidative reaction was measured. Regeneration of the reactor was made by pumping 10 mM N,N-diethyldithiocarbamate solution (pH 8.0).


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15
フローセル型電気化学ルミネッセンスセンサ

相澤益男・田中 俊*・篠原寛明・碇山義人

T D K開研*・東工大工

FLOW CELL TYPE SENSOR FOR ELECTROCHEMILUMINESCENCE

Masuo AIZAWA, Masaru TANAKA*, Hiroaki SHINOHARA and Yoshihito IKARIYAMA

Department of Bioengineering, Tokyo Institute of Technology
Meguro-ku, Tokyo 152, Japan
*R&D center, TDK Co.,
Ichikawa-shi, Chiba 272, Japan

A new detecting system for electrochemiluminescence has been developed for the sensitive assay of biochemical substances. The sensing device is a two electrode system combined with a photomultiplier. When the sensing device is applied to the flow through detector of electrochemiluminescence of luminol. Luminol can be detected as low as 10-9 mol・dm-3. The new device is feasible as a flow cell type detecting system of enzyme assay and immunoassays. The detailed fabrication procedure and fundamental characteristics of the luminescence sensing system are described.


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16
ポリエステル系可塑剤を用いたK+-ISFET

田口敏行・伊藤 忠・稲垣 大・五十嵐伊勢美

豊田中研

K+-ISFETs CONTAINING POLYESTER PLASTICIZERS

Toshiyuki TAGUCHI, Tadashi ITO, Hajime INAGAKI and Isemi IGARASHI

Toyota Central Research & Development Laboratories, Inc.
Nagakute, Aichi 480-11, Japan

K+-ISFET with polyvinylchloride/polyester plasticizer/valinomycin membranes have been investigated. The K+ sensitivity and selectivity, response time, thermal characteristics, and long-term stability were evaluated. The ISFETs indicated linear responses to K+ ions in the range of 0.1-100 mM in the presence of 100 mM NaCl, and the sensitivities were 52-56 mV/decade. There was no marked change in the sensitivity and the response time during 60 days in aqueous storage. The improved long-term stability of the ISFETs is attributed to the high viscosity and the high molecular weight (1500-8000) of the plasticizers.


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17
膜被覆イオンセンサを用いた生体関連物質溶液中におけるイオン濃度測定

牛沢典彦・曽根 厚・滝浪雅夫・山口秀一郎・下村 猛

テルモ

MESUREMENT OF ION CONCENTRATIONS IN BODY FLUIDS USING BY ION SELECTIVE ELECTRODE COATED WITH BILAYER POLYMER FILMS

Norihiko USHIZAWA, Atsuhi SONE, Masao TAKINAMI, Shuichiro YAMAGUCHI and Takeshi SHIMOMURA

Technical R&D Devision, Terumo Corporation
Fuji-shi, Shizuoka 417, Japan

Electrode characteristics of ion (pH, Na+, K+, Ca2+) selective electrodes based on bilayer film coating, where the inner films are electroactive electropolymerized ones and the outer layer films are composed of conventional ion selective materials, are described. The ion selective coefficients and the response linearity range were almost comparable to those of conventional liquid membrane electrodes. In body fluids, responses are attributed to amino acid end group, hydroxy, amino and other polarizable species.


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18
フロンガスの検知

小宮弘隆・木村伸一

バイオニクス機器

FREON DETECTION BY AN ELECTROCHEMICAL SENSOR

Hirotaka KOMIYA and Shinichi KIMURA

Bionics Instrument Co., Ltd.
6-1254-2 Shimizu Higashiyamato, Tokyo 189, Japan

There are several instruments on the market today for detecting halogenated hydrocarbons like freons. A new method has been developed by combining an electrochemical sensor and a hot filament. Halogenated hydrocarbons such as CHClF2, CCl2F2 etc, which are non-electroactive gases can be detected by a HCl sensor after pylolysis over a heated filament. It was hard to detect freons like CF4 and CF3Br which don't contain chlorine atoms and are chemically and thermally very stable. It was confirmed that this system can be detect TLV level of carbon tetrachloride (CCl4).


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19
ヨウ素の還元を利用したフッ化水素ガスセンサ

石地 徹・高橋勝緒*

理研計器・理化学研究所*

HYDROGEN FLUORIDE GAS SENSOR USING ELECTROREDUCTION OF IODINE

Toru ISHIJI and Katsuo TAKAHASHI*

RIKEN KEIKI CO., LTD
2-7-6 Azusawa Itabashi-ku, Tokyo 174, Japan

*RIKEN Institute of Physical and Chemical Research
2-1 Hirosawa Wako-shi, Saitama 351-01, Japan

Reaction properties of 6H+ + 5I- + IO3-→3I2 + 3H2O and I2 + 2e-→2I- were investigated for development of a HF-gas sensor. A base (KOH or K2CO3) is added to the solution of KI + KIO3 to stabilize the solution. Effect of the additional base on the liberation of I2 induced by added H+ was examined by means of a polarography and a visible spectroscopy. Good linier relationship between reduction current of the iodine and the added acid amount was obtained, and little influence of the base was observed on its relationship. This reaction system will be effective for the detection of acidic gases.


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20
架橋・4級化ポリビニルピリジンを用いた湿度センサ

松口正信・酒井義郎・定岡芳彦・橋本州生・樋口有理香

愛媛大工

A HUMIDITY SENSOR USING CROSSLINKED QUATERNIZED POLYVINYLPYRIDINE

Masanobu MATSUGUCHI, Yoshiro SAKAI, Yosihiko SADAOKA, Kunio HASHIMOTO, Yurika HIGUCHI

Department of Industrial Chemistry, Faculty of Engineering, Ehime University
Matsuyama-shi, Ehime 790, Japan

Poly(4-vinylpyridine) was simultaneously crosslinked and quaternized with α,ω-dichloroalkane to prepare water resistive but highly humidity sensitive materials. The effect of crosslinking reagent and reaction conditions on the properties for humidity sensors was examined. The sensitivity, hysteresis and response were determined by the percentage of quaternization while the resistivity to water was determined by the chain length of crosslinking reagent.


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21
加熱型湿度センサ

鈴木隆之・二田穂積

矢崎計器

HOT STATE HUMIDITY SENSOR

Takayuki SUZUKI and Hozumi FUTATA

Yazaki Meter Co., Ltd. Gas Appliance Laboratory
23 Minamikashima Futamata Tenryushi, Shizuoka 431-33, Japan

A prototype of hot state humidity sensor is fabricated out of a kind of zeolite that is known as widely-used industrial desiccating agents or adsorbents. Experiments on a carbon-dioxide sensor developed from zeolite show that this sensor is capable of sensing water-vapor, besides carbon-dioxide gas, in the atmosphere and even in relatively higher temperature as it is heated up, and hence it enables us to make up a new type sensor. The sensitivity of this type of humidity sensor is, for example, about 3 mV (as output voltage) under the absolute humidity of 10 g/m3, i.e. in the atmosphere contains 10 grams of water-vapor per m3 (equivalent to 60% R.H. at 20℃), and about 8 mV under the absolute humidity of 50 g/m3 (equivalent to 60% R.H. at 50℃).


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22
無孔性ナトリウムイオン導電体の作製とその特性

松口正信・定岡芳彦・酒井義郎

愛媛大工

PREPARATION OF NON-POROUS SODIUM IONIC CONDUCTOR AND ITS ELECTRICAL BEHAVIOR

Masanobu MATSUGUCHI, Yoshihiko SADAOKA and Yoshiro SAKAI

Department of Industrial Chemistry, Faculty of Engineering, Ehime University
Matsuyama-shi, Ehime 790, Japan

To make sodium super ionic conductor for solid-electrolyte gas sensors, the Na3Zr2Si2PO12 crystal-sodium aluminosilicate particles were filled without any deformations of Na3Zr2Si2PO12. The activation energy in conduction for these composites were lowered to ca. 0.3 eV and the conductivity was enhanced by adding a lower contents of the glass.


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23
カルコゲナイドガラスを用いた銅イオンセンサ

村松正浩・喜多尾道火児・山本達夫

静岡大電工研

Ag ION SENSOR USING CHALCOGENIDE GLASS

Masahiro MURAMATSU, Michihiko KITAO and Tatsuo YAMAMOTO

Research Institute of Electronics, Shizuoka University
3-5-1 Johoku, Hamamatsu 432, Japan

Chalcogenide glasses are promising membrane materials for ion-selective electrochemical sensors. It is said that chalcogenide glass sensor for Ag+ ion is more selective and more stable in strong acid, oxidizing and corrosive media compared to conventional crystalline cation-selective electrodes. It has been established that the ionic sensitivity of chalcogenide glass sensors is governed by the direct exchange of ions (Ag+) between solution and intrinsic or induced exchange sites in the modified surface layer of the vitreous membrane. As an ion-selective electrode membrane, we have used chalcogenide glasses of the silver-arsenic-selenium system, which have bulk and thin film structures.


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24
希土類―銀―β―アルミナの各種ガス共存下での高感応特性

西岡康隆・荒川 剛・足立吟也

阪大工

PHOTOSENSITIVE PROPERTIES OF (Ln3+, Ag+)-β-ALUMINA UNDER VARIOUS GASEOUS ATMOSPHERES

Yasutaka NISHIOKA, Tsuyoshi ARAKAWA and Gin-ya ADACHI

Department of Applied Chemistry, Faculty of Engineering, Osaka University
2-1 Yamadaoka Suita, Osaka 565, Japan

The photosensitive properties of (Ln3+, Ag+)-β-alumina (Ln=Eu, Ce) were studied under various gaseous atmospheres. The deposition of Ag from Ag+-β-alumina under photoirradiation was easily occurred without adsorption of various gases. The deposition of Ag from (Ln3+, Ag+)-β-alumina was caused under adsorption of amine compounds and revealed drastic change between Ce3+ and Eu3+. When the degassed (Ce3+, Ag+)-β-alumina was exposed to ammonia, methylamine and so on, the deposition of Ag was observed although in the case of alcohol, water or CHCl3, Ag almost never deposited. The deposition of Ag for (Eu3+, Ag+)-β-alumina was not caused except for ethylenediamine. Further, from the measurement of ESCA and XMA, the mechanism of the deposition of Ag was briefly discussed.


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25
プロトン導電体厚膜を用いた電流検出型水素センサ

原田達朗・清水陽一・三浦則雄・山添 昇

九大総理工

AMPEROMETRIC HYDROGEN SENSOR USING PROTON-CONDUCTOR THICK-FILM

Tatsuro HARADA, Youichi SHIMIZU, Norio MIURA and Noboru YAMAZOE

Department of Materials Sciences and Technology, Graduate School of Engineering Sciences, Kyushu University
Kasuga-shi, Fukuoka 816, Japan

An amperometric solid-state sensor using a proton-conductor (antimonic acid) thick film (ca. 20 μm) was developed for detecting small amount of hydrogen in air at room temperature. The thick film was formed on an alumina substrate by a spin-coating method. The sensor element had a laminated-type structure in which the thick film was sandwiched by sputtered Pt electrodes. The short-circuit current of the sensor was in direct proportion to the concentration of hydrogen. The 90% response time was as short as ca. 10 s at 30℃. Large humidity dependence of the current response was found to be attenuated by connecting an appropriate external-resistance to the sensor element in series.


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26
BaCeO3系焼結体を用いた中、高温作動型水素センサ

内田裕之・長門秀樹・岩原弘育

鳥取大工

HIGH AND MEDIUM TEMPERATURE-TYPE HYDROGEN SENSOR USING BaCeO3-BASED SINTERS

Hiroyuki UCHIDA, Hideki NAGATO and Hiroyasu IWAHARA

Department of Environmental Chemistry and Technology, Faculty of Engineering, Tottori University
Koyama-cho, Tottori 680, Japan

A hydrogen concentration cell was constructed by using high temperature-type proton conducting oxide sinters based on BaCeO3 for the purpose of applying it to a hydrogen sensor. The concentration cell gave rise to a stable electromotive force in correspondence to hydrogen partial pressure. The emfs were in good agreement with the theoretical values and the response speed was fast. Due to its high protonic conductivity, working temperature range of the sensor was very wide from 200 to 900℃.


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27
限界電流式酸素センサ - 酸素分圧測定における拡散律速体細孔径の影響

近藤春義・佐治啓市・山田 靖・高橋英昭・五十嵐伊勢美

豊田中研

LIMITING CURRENT-TYPE OXYGEN SENSOR
INFLUENCE OF THE PORE DIAMETER OF A DIFFUSION LIMITING SUBSTRATE FOR MEASUREMENT OF OXYGEN PARTIAL PRESSURE

Haruyoshi KONDO, Keiichi SAJI, Yasushi YAMADA, Hideaki TAKAHASHI and Isemi IGARASHI

Toyota Central Research and Development Laboratories, Inc.
Nagakute-cho Aichi-gun, Aichi 480-11, Japan

The sensor output vs. oxygen partial pressure characteristics of a thin film limiting current-type oxygen sensor were studied. In experiments, the porous alumina substrates having pore diameters of 800Å and 2000Å were employed as the diffusion limiting layer of the sensor. The sensor characteristics were measured at 750℃ in the pressure range of 0.05-2 atm of O2-N2 mixtures. In the results, the output current for the sensor with the substrate having a diameter of 800Å was more linear to oxygen partial pressure than that for another sensor. The pressure dependence of these sensor outputs was in good agreement with calculated results from the pore diameter measured by a porosimeter.


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28
防水型ジルコニア酸素センサの特性と応用

浅田昭良・石橋功成・中沢光博

藤倉電線

SOME PROPERTIES AND APPLICATIONS OF WATER PROOF TYPE OF ZIRCONIA OXYGEN SENSOR

Akiyoshi ASADA, Kohsei ISHIBASHI and Mitsuhiro NAKAZAWA

Tokyo Laboratory, FUJIKURA Ltd.
1-5-1 Kiba Koto-ku, Tokyo 135, Japan

A limiting current type of zirconia oxygen sensor having water proof property has been developed. The water proof property was realized by employing porous TEFLON membrane in the sensor. Structure and characteristics of the sensor are introduced. A response time is not affected by existance of TEFLON membrane. Practical application of the water proof type of oxygen sensor is reported. Continuous measurement of oxygen concentration in soil is possible by using this oxygen sensor.


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29
H2-H2Oガス雰囲気におけるジルコニア酸素センサの電極反応速度

水崎純一郎・田川博章・磯部健介*・平野克比古*・笛木和雄**

横浜国大環境研セ・芝浦工大工*・東理大理工**

RESPONSE AND ELECTRODE REACTION OF ZIRCONIA OXYGEN GAS SENSOR IN H2-H2O ATMOSPHERES

Junichiro MIZUSAKI, Hiroaki TAGAWA, Kensuke ISOBE*, Katsuhiko HIRANO *and Kazuo FUEKI**

Institute of Environmental Science and Technology, Yokohama National University
Yokohama-shi 240, Japan
*Department of Industrial Chemistry, Shibaura Institute of Technology
Minato-ku, Tokyo 108, Japan
**Department of Industrial Chemistry, Faculty fo Science and Engineering, Tokyo University of Science
Noda-shi, Chiba 278, Japan

Using the electrochemical cell [sample gas, Pt/YSZ/Pt, air], with H2-H2O as the sample gas, the complex impedance of the H2-H2O, Pt/YSZ electrode and the steady-state EMF were measured. The results were compared with those of the cells with CO-CO2 and O2-Ar gases. It was found that the rate of electrode reaction with H2-H2O gas is about 100 times larger than that with CO-CO2. At temperatures below 500℃, the reaction rate in H2-H2O gas is faster than that in O2 atmospheres. The high reaction rate of H2-H2O, Pt/YSZ electrode results in the good response of zirconia oxygen sensors to H2-H2O gas at temperatures as low as 300℃.


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30
ISFETによるポテンシオメトリック酸素センシング

伊藤善孝・堤 和夫・平井 実

親電元工業

POTENTIOMETRIC OXYGEN SENSOR WITH ISFET

Yohitaka ITOH, Kazuo TSUTSUMI and Minoru HIRAI

Research & Development Division, Shindengen
Hanno-shi, Saitama 357, Japan

In this paper a potentiometric sensor with ISFET is reported and discussed the possibilities of a new type of oxygen sensor at room temperature. ISFET can be used as an impedance transformation device and an insulator electrode. Whose potential voltage is kept the constant value under the pH of an electrolyte is constant. The oxygen sensor consists of a working electrode, platinum or gold, and an ISFET and coated with a polymeric geland covered with a gas permeable membrane. Output sensitivity of about 60 mV/decade is obtained with gold electrode and oxygen partial pressure from 0.01 to 1.0 are measured with linearity. The response time of the sensor upon an increase and a decrease in oxygen partial pressure is approximately 2 min and 3 min, respectively.


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31
透過膜、電極、電解質を一体化させた酸素センサ(3)
酸素の検出に及ぼす環境因子の影響

片倉勝巳・小久見善八*・竹原善一郎*

奈良高専・京大工*

AN OXYGEN SENSOR STRUCTURED WITH TIGHTLY STACKED MEMBRANE/ELECTRODE/ELECTROLYTE (3)
INFLUENCE OF THE CIRCUMSTANCE FACTORS ON OXYGEN DETECTION

Katsumi KATAKURA, Zempachi OGUMI* and Zen-ichirou TAKEHARA*

Department of Chemical Engineering, Nara National College of Technology
Yata-cho Yamatokouriyama-shi, Nara 639-11, Japan
*Department of Industrial Chemistry, Kyoto University
Sakyo-ku, Kyoto 606, Japan

An amperometric oxygen sensor operating at room temperature is constructed from Nafion, porous platinum and a polyethylene film. A porous platinum cathode is directly deposited on Solid Polymer Electrolyte (Nafion) and it is covered with polyethylene film, which acts as an oxygen permiative membrane, by a hot press method. A limiting reduction current which is decided by oxygen diffusion rate through the permiative membrane is observed and the value changes in proportion to oxygen concentration of gas up to 100%. The sensor is stable more than 100 days in air and the response time is less than 20 s.


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32
長寿命ガルバニ電池式酸素センサの開発

工藤寿士・藤田雄耕

日本電池

DEVELOPMENT OF LONG-LIFE GALVANIC-TYPE OXYGEN SENSOR

Hisashi KUDO and Yuko FUJITA

Japan Storage Battery Co., Ltd.
Nishinosho Kisshoin Minami-ku, Kyoto 601, Japan

A very long-life Galvanic-type oxygen sensor has been developed. The electrolyte of the sensor is weak acid buffer solution consisting 5 M/L AcOH-4 M/L AcOK-0.1 M/L (AcO)2Pb(pH=6.1). The cathode is porous Au Spattered on a surface of FEP membrane and current collector of the cathode is carbon paper. This sensor has not only very stable out-put voltage, but also 10 to 20 times longer life than that of KOH electrolyte, and is not affected by acidic gas such as CO2 at all.


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33
マイクロマシーニングによる磁気式酸素センサ

仲野 陽・江刺正喜・大見宏弘・桂 正樹*

東北大工・東芝総研*

MAGNETIC OXYGEN SENSOR FABRICATED BY MICROMACHINING

Akira NAKANO, Masayoshi ESASHI, Tadahiro OHMI and Masaki KATSURA*

Department of Electronic Engineering, Tohoku University
Aoba Aramaki, Sendai, Japan
*Research and Development Center, Toshiba Corporation
Komukai Toshiba-cho Saiwai-ku, Kawasaki, Japan

Miniature magnetic oxygen sensor was fabricated on a silicon wafer by micromachining techniques. It has flow channels and nickel micro heaters in a silicon wafer anodically bonded to a pyrex glass. This has linear sensitivity in the range of 20-70% oxygen concentration.


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34
固定化液膜型CO2ガスセンサ用の溶媒の探索

呉 霞琴・清水康博・江頭 誠

長崎大工

INVESTIGATION OF AN ADEQUATE SOLVENT FOR A CO2 GAS SENSOR BASED ON IMMOBILIZED LIQUID MEMBRANE

Xia-Qin WU, Yasuhiro SHIMIZU, Makoto EGASHIRA

Department of Materials Science and Engineering, Faculty of Engineering, Nagasaki University
1-14 Bunkyo-machi, Nagasaki 852, Japan

To find an adequate solvent for a sensor element based on immobilized liquid membrane, cyclic voltammograms of several anhydrous solutions dissolving K2CO3 have been measured after bubbling mixed gases of CO2 and air through the solutions. The current-potential curves on the negative scan obtained with a Au working electrode were sensitive to concentration changes of CO2 in the mixed gases, but the behavior was strongly dependent upon the kind of solutions. A cathodic peak corresponding to electrochemical reduction of dissolved CO2 increased and became sharp with a decrease in molecular weight of the solvent at the same CO2 concentration. As a result, the ratio of the current after bubbling air vs. CO2-containing gases (Iair/ICO2) under the same potential varied markedly with the concentration of CO2. Among the solvents studied, ethylene glycol was most promising to realize higher CO2 sensitivity of the sensor element.


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特別講演2
THE PRESENT STATUS OF CHEMICAL SENSOR TECHNOLOGY IN KOREA

Kyung-Sul Yun

Korea Advanced Institute of Science and Technology
Seoul, Korea

An interest in chemical sensors has greatly grown up in recent years in Korea. Because the chemical sensors provide essential components for monitoring and autornatic control systems, they have been recognized as a new high-tech area in modern applied science. Recently a feasibility study on the sensor development has been done by KAIST and KSRI under governmental support. They surveyed the status of sensor application, production and R & D activities including researchers, organizations and research trends in home and abroad. Refered to this report the present status of chemical sensor technology in Korea will by summarized.


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35
SnO2系H2Sガスセンサ

兼房慎二・新田正義・原留美吉

日大生産工

SnO2-BASED H2S GAS SENSORS

Shinji KANEFUSA, Masayoshi NITTA and Miyoshi HARADOME

Physical Science Laboratories, College of Industrial Technology, Nihon University
Narashino-shi, Chiba 275, Japan

H2S gas sensors, made of SnO2 mixed with hydrophobic silica, hydrophilic silica or ZrO2, have been prepared. Differences between their sensitivities to H2S in air and in N2 atmosphere, temperature dependence of their resistivities, and thermal analysis of sensors have been investigated. Sensitivities of SnO2-based sensors to H2S in air and in N2 are almost the same above 200℃ of sensor temperature. A 10 ppm concentration of H2S gas in air changes the resistivity of ZrO2-doped SnO2 sensors to a value 300 times lower than that for air around 180℃.


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36
SnO2-COセンサの温度サイクル効果

守家浩二・中村裕司・山添 昇*

大阪ガス総研・九大総理工*

TEMPERATURE SWING EFFECT ON SnO2-CO SENSOR CHARACTERISTICS

Koji MORIYA, Yuji NAKAMURA and Noboru YAMAZOE*

Osaka Gas Research Center
Osaka-shi, Osaka 554, Japan
*Department of Materials Science and Technology, Graduate School of Engineering Science, Kyushu University
Kasuga-shi, Fukuoka 816, Japan

A stannic oxide semiconductor sensor capable of detecting carbon monoxide in a gas mixture containing water and hydrogen etc. has been developed. It was found that the response time of the sensor, using a temperature swing method (High-Low method), was 30 times shorter compared to the conventional method. The temperature dependence of the resistance was also smaller.


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37
SnO2系ガスセンサにおけるRe及びVの添加効果

岩切豊志・床田裕美・八尋秀典・岩本正和・松浦吉展*・高畠 敬*

宮崎大工・フィガロ技研*

EFFECT OF THE ADDITION OF Re AND V TO SnO2 GAS SENSOR

Toyoshi IWAKIRI, Hiromi TOKODA, Hidenori YAHIRO, Masakazu IWAMOTO, Yohinobu MATSUURA* and Kei TAKAHATA*

Faculty of Engineering, Miyazaki University
Miyazaki-shi, Miyazaki889-21, Japan
*Figaro Engineering Inc.,
Minoo-shi, Osaka 562, Japan

The characterization of adsorbed oxygen and lattice oxygen on SnO2 gas sensors has been studied by means of temperature programmed desorption (TPD) and reduction (TPR) techniques. Here SnO2 alone, SnO2+Pd, SnO2+Pd+SiO2 and SnO2+Pd+SiO2+Re/v were used as sensor samples. It was found that addition of Re and V into the SnO2 sample results in the increment of adsorbed oxygen. In addition, TPD and TPR curves (R.T. -500℃) of all samples have changed with the repetition of the experiments; the change of SnO2+Pd+SiO2+Re/V was most gradual among the samples. These phenomena have been discussed in the connection with the lattice defects in SnO2.


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38
酸化スズスパッタ膜のガス感度特性

辻本浩章・吉川修一・白江公輔

阪大基礎工

GAS SENSITIVITY OF SPUTTERED TIN OXIDE FILM

Hiroaki TSUJIMOTO, Shuichi YOSHIKAWA and Kimisuke SHIRAE

Department of Control Engineering, Faculty of Engineering Science, Osaka University
Toyonaka-shi, Osaka 560, Japan

Tin oxide films had been prepared by reactive sputtering and the relation between sensitivity and inner structure of tin oxide film was investigated. The sensitivity had not been related to the cristalinity of tin oxide film. On the other hand, it was changed remarkable by the O2 concentration or pressure during sputtering. It was shown by XPS that the ratio of O to Sn in film was changed by the preparation conditions and its ratio caused the difference of gas sensitivity. It was confirmed that when the ratio of O to Sn of sputtered tin oxide film was a medium state between SnO and SnO2, its film had a high sensitivity.


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39
ガス識別用SnOx薄膜マルチセンサ

若林淳右・越智久晃・白江公輔

阪大基礎工

SnOx THIN FILM MULTI-SENSOR FOR GAS RECOGNITION

Kiyosuke WAKABAYASHI, Hisaaki OCHI and Kimisuke SHIRAE

Department of Control Engineering, Faculty of Engineering Sciences, Osaka University
Toyonaka-shi, Osaka 560, Japan

This paper reports a new multi-sensor for gas recognition. The tin oxide (SnOx) thin film multi-sensor with five different gas detection properties was integrated on a quartz substrate. The thin film of tin oxide are deposited by reaction RF-sputtering method. When the tin is sputtered, a substrate was heated, such as produce temperature gradient from 250 to 300℃ at both ends of substrate. As a results, the composition gradient of tin oxide are get on a substrate. Finally, the sensor was made by fitting five electrode. The pattern of multi-output for the sensor depend on kind of gas.


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40
ガスセンサによる火災検知の可能性の検討

天本太郎・田中克之・松浦俊二

フィガロ技研

THE POSSIBILITY OF FIRE DETECTION BY SEMICONDUCTOR GAS SENSORS

Taro AMAMOTO, Katsuyuki TANAKA and Shunji MATSUURA

Figaro Engineering Inc.,
Minoo-city, Osaka 562, Japan

We have studied the possibility of fire detection by semiconductor gas sensors through a simulated test fire in a three-story house. Four types of gas sensors whose objective gases are different and an oxygen sensor were evaluated and compared to commercial fire detectors. The testing probe is consisted of an oxygen sensor and the four types of gas sensors. 11 test sets were installed in 11 different locations in the house. The test result shows that the hydrogen sensors detect a fire in the shortest time and they can detect a fire early enough even in a location apart from the origin where the fire starts or in a door closed room as compared to the commercialized fire detectors.


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41
Air Quality Sensor

松本 隆・安永 進・松浦俊二

フィガロ技研

AIR QUALITY SENSOR

Takashi MATSUMOTO, Susumu YASUNAGA and Shunji MATSUURA

Figaro Engineering Inc.
Minoo-shi, Osaka 562, Japan

Recently, people have become more concerned with air contamination in a room, especially with cigarette smoke because of its smell and injury to health. Which led us to become actively engaged in developing a sensor sensitive to cigarette smoke and air contamination. Thus, the Air Quality Sensor was developed. The sensor is easily operated with our newly developed microcomputer, and this unit is applied to an air cleaner. This report describes the summary of the Air Quality Sensor and its microcomputer, and its future.


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42
オート調理用センサ

小野靖典・亀井佐芸子・瀬戸口泰弘・安永 進・松浦俊二

フィガロ技研

SENSORS FOR AUTOMATIC COOKING

Kiyonori ONO, Sakiko KAMEI, Yasuhiro SETOGUCHI, Susumu YASUNAGA and Shunji MATSUURA

Figaro Engineering Inc.
Minoo-city, Osaka 562, Japan

A sensor is the most important device to control cooking automatically in a microwave oven. However, conventional sensors with a wide application in various fields needed some improvements for microwave oven use. Therefore, three kinds of sensors have been developed; a sensor for setting the heating time of food, a sensor for controlling the grilling of food and a sensor for detecting alcohol generated when cooking food. This report describes these three sensors.


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43
半導体ガスセンサを用いた多成分ガス分析法

越智久晃・若林淳右・白江公輔

阪大基礎工

THE ANALYSIS METHOD OF GAS MIXTURE USING SnO2 GAS SENSORS

Hisaaki OCHI, Kiyosuke WAKABAYASHI and Kimisuke SHIRAE

Department of Control Engineering, Faculty of Engineering Science, Osaka University
Toyonaka, Osaka 560, Japan

This paper reports an analysis method of gas mixture by signal processing of some SnO2 gas sensors. The model of the structure of SnO2 gas sensor is supposed with the simple equivalent circuit. On this model, the resistance of sensor can be obtained as the parallel summation of each imaginary resistance, which represented with a function of concentration of each gas in gas mixture. So, if the sorts of SnO2 gas sensors are enough for number of composition gases, we can get concentration of each gas in gas mixture as the solution of simultaneous equations of these sensors.


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44
酸化物半導体による低濃度のPH3の検出

江口浩一・J.S.Cauhape*・F.Menil*・C.Lucat*・J.Portier*

九大総理工・ボルドー大学*

DETECTION OF PHOSPHINE WITH SEMICONDUCTIVE OXIDE THICK FILMS

Koichi EGUCHI*, J. S. CAUHAPE***, F. MENIL**, C. LUCAT*** and J. PORTIER**

*Department of Materials Science and Technology, Graduate School of Engineering Sciences, Kyushu University
Kasuga-shi, Fukuoka 816, Japan
**Laboratoire de Chimie du Solide du C. N. R. S. and ***Laboratoire d'Electronique-E. S. E. L., Universite de Bordeaux I, 351 cours de la Liberation
33405 Talence Cedex, FRANCE

Thick films of n-type iron oxide α-Fe2O3 have been shown to exhibit extremely high sensitivity to phosphine in a concentration range of 1 to 1000 ppm in air. A pretreatment under 2000 ppm of PH3 at 360℃ during 3 h greatly enhanced the sensitivity. Pretreated thick films were selective to PH3, i.e., the resisitance change was negligible for a few percents of CO or CH4 and was about one order of magnitude lower for H2 than for PH3 at 360℃. During the pretreatment of the thick films with 2000 ppm of PH3, iron phosphate layers are likely formed on the surface of the Fe2O3 particles. Iron plays a major role and, for this reason, other binary oxides of Cr, Co, Ni, Zn, and Sn gave much weaker responses or no response at all. Sticking of Fe2O3 thick films on the alumina substrate can be improved by addition of a mineral binder.


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45
鉄酸化物薄膜のガス検知特性の熱処理効果

吉川修一・辻本浩章・白江公輔

阪大基礎工

ANNEALING EFFECT TO GAS DETECTION PROPERTIES OF FexOy THIN FILM

Shuichi YOSHIKAWA, Hiroaki TSUJIMOTO , Kimisuke SHIRAE

Department of Control Engineering, Faculty of Engineering Science, Osaka University
Toyonaka-shi, Osaka 560, Japan

The iron oxides have various compositions and structures, and they are also presented as gas sensors. This paper is concerned with the relation between gas sensitive properties and compositions-and-structures of iron oxide thin films by RF reactive sputtering. The film of 6.25% oxygen ratio suitably annealed in hydrogen atmosphere had a higher sensitivity to propane gas, and after annealing the Xray diffraction pattern showed that this film contained Fe3O4. It is estimated that Fe3O4 changes to γ-Fe2O3 by oxidation at operation temperature, and that the more crystallized γ-Fe2O3 is, the higher the sensitivity to propane gas is.


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46
触媒燃焼式ガスセンサ用Au/Co3O4薄膜触媒の調整とCO酸化活性

小林哲彦・高見健児*・春田正毅・坪田 年・佐野 寛

大工試・大阪電通大*

PREPARATION AND CO OXIDATION ACTIVITIES OF Au/Co3O4 THIN FILM CATALYSTS FOR USE OF CATALYTIC COMBUSTION-TYPE GAS SENSORS

Tetsuhiko KOBAYASHI, Kenji TAKAMI*, Masatake HARUTA, Susumu TSUBOTA and Hiroshi SANO

Government Industrial Research Institute of Osaka
Ikeda, Osaka 563, Japan
*Osaka Electorcommunication University
Neyegawa, Osaka 572, Japan

Thin film catalysts composed of Au and Co3O4 have been prepared by a variety of deposition techniques of gold in an attempt to develop catalytic combustion-type gas sensors. Only the co-sputtering deposition of Au and Co3O4 gave thin films more active than simple Co3O4 film in the catalytic oxidation of CO. The co-sputtered Au/Co3O4 thin films were active at around 150℃ for CO oxidation, which seems to be due to the presence of smaller particles of gold.


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47
Pt/TiO2粒状金属膜の酸素応答特性(III)

小野 洋・堀池彰夫・森崎 弘・矢澤一彦

電通大

Pt/TiO2 GRANULAR METAL FILMS AS AN OXYGEN SENSOR (III)

Hiroshi ONO, Akio HORIIKE, Hiroshi MORISAKI, Kazuhiko YAZAWA

The University of Electro-Communications
Chofu-shi, Tokyo 182, Japan

The electrical resistance of a granular metal film composed of fine Pt particles dispersed in a TiO2 matrix was found to be influenced by ambient atmosphere conditions. The resistance increased up to about 30 percent in high humidity as well as in O2 atmosphere. The sensitivity to humidity appeared at about 100℃, which was about 50℃ lower than the threshold temperature for O2 gas. The effect of humidity on the resistance was discussed with respect to the sensing mechanism of oxygen gas.


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48
3d元素を添加した希土類元素複合酸化物LuMxCo1-xO3(Ln=La,Nd,Sm)の界面状態とセンサ活性

馬場英幸・荒川 剛・足立吟也

阪大工

THE SURFACE STATES AND THE ACTIVITY FOR GAS SENSING OF RARE-EARTH PEROVSKITE OXIDES LuMxCo1-xO3 (Ln: La, Nd and Sm; M: 3d Transition Elements)

Hideyuki BABA, Tsuyoshi ARAKAWA and Gin-ya ADACHI

Department of Applied Chemistry, Faculty of Engineering, Osaka University
Suita-shi, Osaka 565, Japan

The surface states of the semiconductive (p-type) perovskite oxides SmMxCo1-xO3+δ (M: 3d transition metals) as gas sensor material were studied by DLTS (Deep Level Transient Spectroscopy) method. In every perovskite oxide, a single DLTS spectrum with a maximum at a certain temperature Tm was obtained. The activation energy (Et) for Sm M0.2Co0.8O3+δ, where M=Ti, Cr, Mn and Fe, were greater than 0.14 eV for SmCoO3.02 and ranged from 0.2 eV to 0.5 eV above the valence band. Moreover, the correlation between the activity for gas sensing and Et was briefly discussed.


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