JPS60114757A - Gas detecting bridge - Google Patents
Gas detecting bridgeInfo
- Publication number
- JPS60114757A JPS60114757A JP22347483A JP22347483A JPS60114757A JP S60114757 A JPS60114757 A JP S60114757A JP 22347483 A JP22347483 A JP 22347483A JP 22347483 A JP22347483 A JP 22347483A JP S60114757 A JPS60114757 A JP S60114757A
- Authority
- JP
- Japan
- Prior art keywords
- gas
- heater
- gas detection
- series
- detection element
- 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
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/02—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance
- G01N27/04—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance
- G01N27/14—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance of an electrically-heated body in dependence upon change of temperature
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
- G01N33/0004—Gaseous mixtures, e.g. polluted air
- G01N33/0009—General constructional details of gas analysers, e.g. portable test equipment
- G01N33/0011—Sample conditioning
- G01N33/0014—Sample conditioning by eliminating a gas
Landscapes
- Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Analytical Chemistry (AREA)
- General Health & Medical Sciences (AREA)
- Pathology (AREA)
- Immunology (AREA)
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Biochemistry (AREA)
- General Physics & Mathematics (AREA)
- Combustion & Propulsion (AREA)
- Medicinal Chemistry (AREA)
- Food Science & Technology (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Investigating Or Analyzing Materials By The Use Of Fluid Adsorption Or Reactions (AREA)
- Investigating Or Analyzing Materials By The Use Of Electric Means (AREA)
Abstract
Description
【発明の詳細な説明】
この発明は、ガスの濃度等を測定するガス検出器に使用
されるブリッジに関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a bridge used in a gas detector that measures gas concentration and the like.
従来、ガス検出用ブリッジとしては、ガス検出素子およ
び補償素子が直列接続された第１の直列２辺の両端と２
つの抵抗素子が直列に接続された第２の直列２辺の両端
とを接続し、該両接続点を入力端子とするとともに前記
、第１、第２の直列２辺の中間接続点を出力端子とする
ものが知られている。このものは、ガス検出素子を活性
化してガスに反応させるために入力端子を電源に接続し
てガス検出素子、補償素子に通電し、これらガス検出素
子二補償素子を自己発熱させ所定温度まで加熱するよう
にしている。したがって、これらガス検出素子、補償素
子の抵抗値は周囲の温度、入力電圧等の影響を受けるこ
とになる。このような周囲温度、入力電圧等に変動があ
った場合には、ガス検出素子と補償素子とがその利質、
構造等において異なっているため、ガス検出素子の抵抗
値の変化に補償素子の抵抗値の変化が追従できず、これ
によりブリッジのバランスが崩れて測定結果に誤差が発
生するという問題点がある。しかも、ガス検出素子と補
償素子とが比較的離れて設置されていたため、画素子の
周囲の環境が異なり、これにより測定結果に誤差が発生
するという問題点もある。Conventionally, as a gas detection bridge, a gas detection element and a compensation element are connected in series at both ends of two sides in series and at two sides.
Connect both ends of the second series two sides in which two resistive elements are connected in series, and use the two connection points as input terminals, and the intermediate connection point of the first and second series sides as the output terminal. It is known that In order to activate the gas detection element and make it react to gas, the input terminal is connected to a power source and electricity is applied to the gas detection element and compensation element, causing the gas detection element and compensation element to self-heat and heat up to a predetermined temperature. I try to do that. Therefore, the resistance values of these gas detection elements and compensation elements are affected by ambient temperature, input voltage, etc. When there are fluctuations in the ambient temperature, input voltage, etc., the gas detection element and compensation element
Since they are different in structure, etc., the change in the resistance value of the compensation element cannot follow the change in the resistance value of the gas detection element, which causes a problem in that the bridge becomes unbalanced and errors occur in the measurement results. Moreover, since the gas detection element and the compensation element are installed relatively apart, there is a problem that the environment around the pixel element is different, which causes errors in the measurement results.
この発明は前述の問題点に着目してなされたもので、周
囲の温度変化等に対して安定し、補償効率、すなわちガ
ス検出素子への追従性、の高いガス検出用ブリッジを提
供することを目的としている。This invention has been made in view of the above-mentioned problems, and aims to provide a gas detection bridge that is stable against changes in ambient temperature, etc., and has high compensation efficiency, that is, followability to the gas detection element. The purpose is
このような目的は、ガス検出素子および補償素子が直列
に接続された第１の直列２辺の両端と２つの抵抗素子が
直列に接続された第２の直列２辺の両端とを接続し、該
両接続点を入力端子とするとともに前記第１、第２の直
列２辺の中間接続点を出力端子とするガス検出用ブリッ
ジにおいて、前記ガス検出素子および補償素子をヒータ
内に近接して配置してガス検出素子および補償素子を同
一温度に加熱するようにすることにより達成することが
できる。Such a purpose is to connect both ends of the first two series sides in which the gas detection element and the compensation element are connected in series, and both ends of the second series two sides in which the two resistance elements are connected in series, In a gas detection bridge in which both the connection points serve as input terminals and the middle connection point between the first and second series sides serves as an output terminal, the gas detection element and the compensation element are arranged close to each other within the heater. This can be achieved by heating the gas detection element and the compensation element to the same temperature.
以下、この発明の一実施例の構成を図面に基づいて説明
する。Hereinafter, the configuration of an embodiment of the present invention will be described based on the drawings.
第１図はこの発明を半導体式ガス検出器に使用されるブ
リッジに適用したものであり、同図において、（１）は
半導体式のガス検出素子（２）および温度さらには湿度
も補償する補償素子（３）が直列接続されて構成された
第１の直列２辺である。前記ガス検出素子（２）は例え
ば白金等の細線からなる熱 。Figure 1 shows the application of the present invention to a bridge used in a semiconductor gas detector. These are two first series sides configured by connecting elements (3) in series. The gas detection element (2) is made of a thin wire made of platinum or the like.
線条（４）を有し、この熱線条（４）の中央部に形成さ
牙またコイル部（５）には酸化錫、酸化亜鉛、酸化チタ
ン等のｎ型半導体からなる金属酸化物半導体（６）が塗
布焼結により付着されている。一方、補償素子（３）は
、前記ガス検出素子（２）と同様の熱線条（７）、金属
酸化物半導体（８）で構成された素子の表面に、ガスを
吸着せず水蒸気のみを吸着する透湿層（９）を伺着した
もので、この透湿層（９）は例えば粒子径が０．１〜３
ミクロンの酸化第ニクロム等からなる。ｆｌｕ）（ＩＩ
）は直列に接続された固定および可変抵抗素子であり、
これら固定、可変抵抗素子ｆｌＯ）（Ｉ １）は全体と
して第２の直列２辺（Ｉ２）を構成する。前記第１、第
２の直列２辺ｍ（１２１の両端は互に接続されて入力端
子（１３）α４）となる。従来においては、熱線条（４
）（刀の自己発熱によってガス検出、補償素子（２）（
３）を高温に加熱するために、この人力端子（１３）ｆ
１４１に高電圧を印加したが、この発明においては、ガ
ス濃度等に対応する検出出力電圧を得ることができる程
度の低電圧が印加される。また、前記第１、第２の直列
２辺（１１（１２の中間接続点はそハぞれ出力端子（１
５１αｅとなり、これらの出力端子（１５Ｈ１ｆｉｌに
は例えば電圧計が接続されている。前記ガス検出素子（
２）および補償素子（３）は、第、２図に示すように、
互に近接して配置され、画素子（２）（３）の環境条件
は近似している。また、ａ′７）はヒータであり、この
ヒータａηはセラミックからなる円筒体（１８）と、円
筒体（１８１の外周に厚膜印刷等により付着された抵抗
体（１偵と、から構成され、この抵抗体（１９）の両端
はリード線（２０Ｊ（２１＋を介して図示していない直
流又は交流の電源に接続される。ヒータ（１７）の円筒
体（１８１内には前記ガス検出、補償画素子（２）（３
）が配置され、これらのガス検出、補償画素子（２）（
３）はヒータ（１７）により同一の測定温度例えば、２
００℃から５００℃までの一定温度、に加熱される。A metal oxide semiconductor (made of an n-type semiconductor such as tin oxide, zinc oxide, titanium oxide, etc.) is formed in the central part of the hot wire (4), and the coil part (5) is formed in the central part of the hot wire (4). 6) is attached by coating and sintering. On the other hand, the compensation element (3) does not adsorb gas but only absorbs water vapor on the surface of the element, which is made up of a hot wire (7) and a metal oxide semiconductor (8) similar to the gas detection element (2). The moisture permeable layer (9) has a particle size of, for example, 0.1 to 3.
Consists of micron dichromium oxide, etc. flu) (II
) are fixed and variable resistance elements connected in series,
These fixed and variable resistance elements flO) (I1) constitute the second series two sides (I2) as a whole. The first and second series two sides m (both ends of 121 are connected to each other to form an input terminal (13) α4). Conventionally, hot streaks (4
) (Gas detection and compensation element (2) (by the self-heating of the sword)
3) This manual terminal (13)f is used to heat the
Although a high voltage was applied to 141, in the present invention, a low voltage is applied to the extent that a detection output voltage corresponding to the gas concentration etc. can be obtained. In addition, the intermediate connection points of the first and second series sides (11 (12) are respectively output terminals (1
51αe, for example, a voltmeter is connected to these output terminals (15H1fil).The gas detection element (
2) and the compensation element (3), as shown in FIG.
They are arranged close to each other, and the environmental conditions of the pixel elements (2) and (3) are similar. Further, a'7) is a heater, and this heater aη is composed of a cylindrical body (18) made of ceramic and a resistor (18) attached to the outer periphery of the cylindrical body (181) by thick film printing or the like. , both ends of this resistor (19) are connected to a DC or AC power source (not shown) via a lead wire (20J (21+). Pixel element (2) (3
) are arranged, and these gas detection and compensation pixel elements (2) (
3) is the same measured temperature by the heater (17), for example, 2
It is heated to a constant temperature from 00°C to 500°C.
前記円筒体（１８）の内面には、特定のガスを除去する
触媒層（２２）が付着されている。この触媒層シ２）と
しては、白金属触媒、例えば白金、パラジウム、ロジウ
ム、前記元素の酸化物またはこれらの混合物、合金、あ
るいはホブカライド触媒が使用され、白金属触媒の場合
には水素ガス、ブタンガス等が、ホブカライド触媒の場
合には一酸化炭素ガスが酸化除去される。この結果、ガ
スの選択性が向上し、三フッ化窒素ガス、メタンガス等
のｅｌｆを測定する場合に好適である。A catalyst layer (22) for removing specific gases is attached to the inner surface of the cylinder (18). As this catalyst layer 2), platinum metal catalysts such as platinum, palladium, rhodium, oxides of the above elements, mixtures and alloys thereof, or hobcalide catalysts are used, and in the case of platinum metal catalysts, hydrogen gas, butane gas is used. In the case of a fobcalide catalyst, carbon monoxide gas is oxidized and removed. As a result, gas selectivity is improved, which is suitable for measuring elf such as nitrogen trifluoride gas and methane gas.
次に、この発明の一実施例の作用について説明する。Next, the operation of one embodiment of the present invention will be explained.
まず、入力端子（１３）（１４）を通じて第１、第２の
直列２辺に低電圧を印加するとともに、リード線（：２
０）（２１＋を介して抵抗体（１１に通電する。これに
より、抵抗体（１ｇＩが発熱し、円筒体（１８１を介し
てガス検出素子（２）、補償素子（３）が同一の測定温
度に加熱される。First, a low voltage is applied to the first and second series sides through the input terminals (13) and (14), and the lead wires (:2
0) (Power is applied to the resistor (11) via 21+. As a result, the resistor (1 gI) generates heat, and the gas detection element (2) and compensation element (3) are heated to the same measurement temperature via the cylindrical body (181). heated to.
このような状態において、ガスを円筒体（］８１に導び
くと、ガス中の水素ガス、ブタンガス又は−酸化炭素ガ
スが高温に加熱され活性化した触媒層！２２１に接触し
て酸化除去される。次に、ガスはガス検出素子（２）、
補償素子（３）に接触する。このとき、ガス検出素子（
２）は、熱線条（４）の抵抗と、熱線条（４）のコイル
部（５）にＶ（まれた金属酸化物半導体（６）の抵抗と
が並列接続された回路と等価であるが、一方の金属酸化
物半導体（６）の抵抗値は、ガスの吸着によりガス濃度
に応じて増減し、他方の熱線条（４）の抵抗値は、ガス
検出素子（２）の温度に比例するため、従来においては
周囲温度の影響（放散熱駄が変動するため）を受けたが
、この発明では、ガス検出素子（２）がヒータ０７）に
よって周囲から加熱されているので、周囲温度が変動し
ても温度に変化はなく、常に一定値を維持する。この結
果、ガス検出素子（２）は周囲温度の影響を受けること
なくガスの濃度のみに応じてその合成抵抗値が変動する
。一方、補償素子（３）は透湿層（９）によってガス吸
着が阻止されるので、金属酸化物半導体（８）の抵抗値
は変動せず、また、熱線条（力の抵抗値も、補償素子（
３）がヒータ（１７）によってガス検出素子（２）と同
一温度に加熱されているので、構造等がガス検出素子（
２）と異なっていても周囲温度の影響を受けることなく
常に一定値を維持する。この結果、補償素子（３）の合
成抵抗値は一定となる。このように、ガスの濃度なガス
検出素子（２）の電気型導度の変化のみで測定している
ので、周囲の温１αの採響を受けることはない。このと
き、補償素子（３）は水蒸気のみを透過吸着できるので
、湿度補償が行なわれる。前述のように、ガス検出素子
（２）の合成抵抗値がガス濃度に応じて変動すると、ブ
リッジのバランスが崩Ｊ１て出力端子（１５）（１６）
にガス濃度に対応した出力が現われる。In such a state, when gas is introduced into the cylinder (]81, hydrogen gas, butane gas, or -carbon oxide gas in the gas is heated to a high temperature and comes into contact with the activated catalyst layer!221, where it is oxidized and removed. .Next, the gas is detected by the gas detection element (2),
Contact the compensation element (3). At this time, the gas detection element (
2) is equivalent to a circuit in which the resistance of the hot wire (4) and the resistance of the metal oxide semiconductor (6) connected in parallel to the coil part (5) of the hot wire (4) are connected in parallel. , the resistance value of one metal oxide semiconductor (6) increases or decreases depending on the gas concentration due to gas adsorption, and the resistance value of the other hot wire (4) is proportional to the temperature of the gas detection element (2). Therefore, in the past, it was affected by the ambient temperature (because the heat dissipation temperature fluctuated), but in this invention, the gas detection element (2) is heated from the surroundings by the heater 07), so the ambient temperature does not fluctuate. However, the temperature does not change and always maintains a constant value. As a result, the combined resistance value of the gas detection element (2) varies only according to the gas concentration without being affected by the ambient temperature. On the other hand, since the gas adsorption of the compensation element (3) is prevented by the moisture permeable layer (9), the resistance value of the metal oxide semiconductor (8) does not change, and the resistance value of the thermal wire (force) is also compensated. element(
3) is heated to the same temperature as the gas detection element (2) by the heater (17), so the structure etc. is similar to that of the gas detection element (2).
Even if it differs from 2), it always maintains a constant value without being affected by the ambient temperature. As a result, the combined resistance value of the compensation element (3) becomes constant. In this way, since the measurement is performed only based on the change in the electrical conductivity of the gas detection element (2) due to the gas concentration, the measurement is not affected by the ambient temperature 1α. At this time, since the compensation element (3) can permeate and adsorb only water vapor, humidity compensation is performed. As mentioned above, when the combined resistance value of the gas detection element (2) changes depending on the gas concentration, the balance of the bridge is lost and the output terminals (15) and (16)
An output corresponding to the gas concentration appears.
第３図はこの発明の他の実施例を示す図である。この実
施例においては、ヒータ（２５）をニクロム線からなる
コイル（２６）で構成し、このコイルレ６）内にガス検
出素子（２）、補償素子（３）を配置している。FIG. 3 is a diagram showing another embodiment of the invention. In this embodiment, the heater (25) is constituted by a coil (26) made of nichrome wire, and a gas detection element (2) and a compensation element (3) are arranged within this coil array (6).
他の構成、作用については前記実施例と同様である。The other configurations and functions are the same as those in the previous embodiment.
なお、前記実施例においては、ガス検出素子（２）が半
導体型の検出素子であったが、このガス検出素子は接触
燃焼型の検出素子であってもよい。In the above embodiment, the gas detection element (2) is a semiconductor type detection element, but this gas detection element may be a catalytic combustion type detection element.
この場合には、ヒータａ７ｃａ（ト）上において可燃性
ガスが燃焼しないようにヒータＱ７）ｔ２５＋表面に、
ガスに対して不活性の金属酸化物、例えば酸化クロム、
四三酸化鉄、酸化金を付着するとよい。In this case, on the surface of heater Q7) t25+, to prevent combustible gas from burning on heater a7ca(g),
Metal oxides that are inert to gases, such as chromium oxide,
It is best to attach triiron tetroxide or gold oxide.
以上説明したように、この発明によれば、周囲の温度変
化等に対して安定し、補償効率の高いブリッジにするこ
とができる。As described above, according to the present invention, it is possible to provide a bridge that is stable against changes in ambient temperature and has high compensation efficiency.
第１図はこの発明の一実施例を示すその回路図、第２図
はヒータ近傍の断面図、第３図はこの発明の他の実施例
を示すヒータ近傍の斜面図である。
（１）・・・・・・第１の直列２辺 （２）・・・ガス
検出素子（３）・・・・・・補償素子 （ＩＯ＋（１１
）・・・抵抗素子（１２）・・・・・・第２の直列２辺
（１３）（１４）・・・入力端子（１５１（１（ｉｌ
・・・出力端子 （１７）・・・・・ヒータ特許出願人
理研計器株式会社
代理人 弁理士 多 １）敏 雄
第１図
第２図
第３図FIG. 1 is a circuit diagram showing one embodiment of the invention, FIG. 2 is a sectional view of the vicinity of the heater, and FIG. 3 is a perspective view of the vicinity of the heater, showing another embodiment of the invention. (1)...First series two sides (2)...Gas detection element (3)...Compensation element (IO+(11)
)...Resistance element (12)...Second series two sides (13)(14)...Input terminal (151(1(il)
... Output terminal (17) ... Heater patent applicant Riken Keiki Co., Ltd. agent Patent attorney Ta 1) Toshio Figure 1 Figure 2 Figure 3
Claims (1)
直列２辺の両端と２つの抵抗素子が直列に接続された第
２の直列２辺の両端とを接続し、該両接続点を入力端子
とするとともに前記第１、第２の直列２辺の中間接続点
を出力端子とするガス検出用ブリッジにおいて、前記ガ
ス検出素子および補償素子をヒータ内に近接して配置す
ることにより、ガス検出素子および補償素子を同一温度
に加熱するようにしたことを特徴とするガス検出用ブリ
ッジ。Connect both ends of the first two series sides in which the gas detection element and the compensation element are connected in series and both ends of the second series two sides in which the two resistance elements are connected in series, and input the two connection points. In a gas detection bridge having a terminal and an intermediate connecting point between the first and second series sides as an output terminal, the gas detection element and the compensation element are disposed close to each other in the heater. A gas detection bridge characterized in that an element and a compensation element are heated to the same temperature.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22347483A JPS60114757A (en) | 1983-11-28 | 1983-11-28 | Gas detecting bridge |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22347483A JPS60114757A (en) | 1983-11-28 | 1983-11-28 | Gas detecting bridge |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS60114757A true JPS60114757A (en) | 1985-06-21 |
Family
ID=16798701
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP22347483A Pending JPS60114757A (en) | 1983-11-28 | 1983-11-28 | Gas detecting bridge |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS60114757A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010008248A (en) * | 2008-06-27 | 2010-01-14 | Honda Motor Co Ltd | Gas sensor |
| EP3901623A4 (en) * | 2018-12-17 | 2022-08-24 | TDK Corporation | Gas sensor |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS52101097A (en) * | 1976-02-20 | 1977-08-24 | Hitachi Ltd | Gas sensor element |
-
1983
- 1983-11-28 JP JP22347483A patent/JPS60114757A/en active Pending
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS52101097A (en) * | 1976-02-20 | 1977-08-24 | Hitachi Ltd | Gas sensor element |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010008248A (en) * | 2008-06-27 | 2010-01-14 | Honda Motor Co Ltd | Gas sensor |
| EP3901623A4 (en) * | 2018-12-17 | 2022-08-24 | TDK Corporation | Gas sensor |
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