JPH0648409Y2 - Low concentration gas analyzer - Google Patents
Low concentration gas analyzerInfo
- Publication number
- JPH0648409Y2 JPH0648409Y2 JP1988146333U JP14633388U JPH0648409Y2 JP H0648409 Y2 JPH0648409 Y2 JP H0648409Y2 JP 1988146333 U JP1988146333 U JP 1988146333U JP 14633388 U JP14633388 U JP 14633388U JP H0648409 Y2 JPH0648409 Y2 JP H0648409Y2
- Authority
- JP
- Japan
- Prior art keywords
- gas
- current
- concentration
- limiting
- circuit
- 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.)
- Expired - Lifetime
Links
Description
【考案の詳細な説明】 ［産業上の利用分野］ この考案は、限界電流式低濃度用ガスセンサにおいて、
これが高濃度のガス雰囲気に曝されると、センサエレメ
ントである固体電解質に大電流が流れることにより、そ
の劣化の進行が速くなるが、それを防止することができ
る低濃度用ガス分析計に関する。[Detailed Description of the Invention] [Industrial field of application] This invention relates to a limiting current type low concentration gas sensor,
When this is exposed to a high-concentration gas atmosphere, a large current flows through the solid electrolyte that is the sensor element, which accelerates the deterioration thereof, but relates to a low-concentration gas analyzer that can prevent this.
［従来の技術］ 限界電流式ガス濃度センサとしては、従来から例えば酸
素ガスのイオン伝導性を有する安定化ジルコニアをセン
サエレメントとしたものがよく知られている。これは安
定化ジルコニアの固体電解質板の両面に白金の多孔質電
極を形成し、その片面に、その面の電極を覆つてガス拡
散室を形成するように、ガス拡散制限孔を有するキヤツ
プを封着したものであつて、上記の２つの電極間に電圧
を印加すると、上記固体電解質板を通して酸素イオンが
移動し、そのイオンをキヤリアとして電流が流れる。そ
の電圧を次第に上昇して行くと、ある電圧の範囲では電
圧を上昇させても電流は増加しない領域が存在する。そ
の領域は限界電流領域と呼ばれ、その電流値はガス濃度
に対応する値である。[Prior Art] As a limiting current type gas concentration sensor, a sensor element in which a stabilized zirconia having an ionic conductivity of oxygen gas is used as a sensor element has been well known. This forms a porous electrode made of platinum on both sides of a solid electrolyte plate of stabilized zirconia, and seals a cap having gas diffusion limiting holes on one side so as to cover the electrode on that side and form a gas diffusion chamber. When a voltage is applied between the two electrodes, the oxygen ions move through the solid electrolyte plate, and a current flows through the ions as carriers. When the voltage is gradually increased, there is a region where the current does not increase even if the voltage is increased within a certain voltage range. The region is called the limiting current region, and the current value is a value corresponding to the gas concentration.
このようなガス濃度センサでは、測定すべき所定のガス
が低濃度であると、それにしたがつて限界電流値も低く
なるので、低濃度測定用としては、限界電流値を高めて
それを読み取り易くするために、すなわち測定装置の感
度をよくするために、高濃度測定用の場合に比してガス
拡散制限孔を大きくしている。In such a gas concentration sensor, if the concentration of a predetermined gas to be measured is low, the limiting current value is accordingly low, so for low concentration measurement, the limiting current value is increased to make it easier to read. In order to improve the sensitivity of the measuring device, the gas diffusion limiting hole is made larger than in the case of high concentration measurement.
［考案が解決しようとする課題］ 低濃度測定用ガス分析計は、例えば半導体の製造や電子
部品の製造加工の際に、その製造加工雰囲気の酸素ガス
を窒素ガス雰囲気に置換する必要があり、雰囲気中の酸
素ガスの濃度を非常に低くした101〜102ppmオーダーの
濃度を精度よく測定する場合に使用されている。このよ
うな製造加工は、被加工品を加工室の中に搬入し、加工
完了後に加工室から取り出すが、その際の扉の開閉で外
部から大気が侵入し、上記の分析計は急に101〜102オー
ダーから2.1×105オーダーの酸素雰囲気に曝されること
になる。また、被加工品を加工室に搬入し、酸素含有雰
囲気を充分に窒素雰囲気を置換するまで分析計でそれを
監視する必要がある。[Problems to be Solved by the Invention] In a gas analyzer for low concentration measurement, it is necessary to replace the oxygen gas in the manufacturing / processing atmosphere with a nitrogen gas atmosphere, for example, in manufacturing semiconductors or manufacturing / processing electronic components. It is used when accurately measuring the concentration of the order of 10 1 to 10 2 ppm when the concentration of oxygen gas in the atmosphere is extremely low. In such manufacturing and processing, the work piece is carried into the processing chamber and taken out of the processing chamber after the processing is completed. It is exposed to an oxygen atmosphere of the order of 1 to 10 2 to the order of 2.1 × 10 5 . Further, it is necessary to bring the workpiece into the processing chamber and monitor it with an analyzer until the oxygen-containing atmosphere is sufficiently replaced with the nitrogen atmosphere.
このような状況で分析計を作動させておくと、大気が流
入した雰囲気では、監視電圧としてのある一定の電圧に
おける最高の電流が固体電解質板を流れ、これが繰り返
されて、固体電解質はしばしば大電流に曝されることに
なつて、その劣化が速められ、分析計としての寿命が損
なわれる。If the analyzer is operated in such a situation, the maximum current at a certain voltage as the monitoring voltage flows through the solid electrolyte plate in the atmosphere into which the air flows, and this is repeated, and the solid electrolyte often becomes large. When exposed to an electric current, its deterioration is accelerated and its life as an analyzer is impaired.
［課題を解決するための手段］ この考案の低濃度用ガス分析計は、低濃度ガスの測定用
であるにもかかわらず高濃度のガスにも曝されねばなら
ない使用の場合にも、上記のように固体電解質に大電流
が流れないようにしたものであつて、分析計の固体電解
質板の両面の電極間に印加する定電圧回路に、その間に
流れる電流がある電流値以下では電圧回路は閉じられて
いるが、ある電流値に達するとその回路は開かれるかま
たはそれ以上には電流が増加されないように、電流制限
回路を付加してなるものである。[Means for Solving the Problems] The low-concentration gas analyzer according to the present invention is used for measuring low-concentration gas, but also in the case of use in which it must be exposed to high-concentration gas, In this way, a large current is prevented from flowing in the solid electrolyte, and in the constant voltage circuit applied between the electrodes on both sides of the solid electrolyte plate of the analyzer, the voltage circuit is It is closed, but it is provided with a current limiting circuit so that the circuit is opened or the current is not further increased when a certain current value is reached.
［作用］ この考案の低濃度用ガス分析計は、上記のような構成で
あるので、101〜102ppmオーダーの酸素ガス雰囲気で作
動していた分析計のセンサエレメントが大気のような10
5ppmオーダーの高濃度の酸素ガス雰囲気に曝されるよう
になつても、それに応じた出力電流かまたは監視電圧に
おける最高の出力電流にまで増加することなく、それ以
下のある電流値に達すると電圧回路は開かれて電流は流
れなくなるか、またはそのある電流値以上には増加され
なくなる。[Operation] Since the low-concentration gas analyzer of the present invention is configured as described above, the sensor element of the analyzer operating in an oxygen gas atmosphere of the order of 10 1 to 10 2 ppm has a sensor like the atmosphere.
When exposed to a high-concentration oxygen gas atmosphere of the order of 5 ppm, when it reaches a certain current value below it, it does not increase to the corresponding output current or the maximum output current at the monitoring voltage. The voltage circuit is opened so that no current flows, or it does not increase above some current value.
［実施例］ この考案の低濃度用ガス分析計の構成の実施例を図面を
参照して説明する。１はイオン伝導性を有する固体電解
質板、例えば酸素ガスのイオン伝導性を有する安定化ジ
ルコニアよりなるもの、2A、2Bは固体電解質板１の両面
に形成された白金よなる多孔質電極、３は固体電解質１
の片面に、その面の電極2Aを覆つてガス拡散室４を形成
するように、封着されたガス拡散制限孔５を有するキヤ
ツプ、Ｅは上記の２つの電極2A、2B間にある一定の電圧
を印加する定電圧源、６はその定電圧回路、７は定電圧
回路６に付加された電流制限回路である。図示の電流制
限回路７はその１例であつて、Q1は増幅器、Q2は判定回
路、R2、R3、R4、R5は増幅用抵抗、R1は電流検出抵抗、
SWはスイツチ素子であつて、この電流制限回路７は、電
流検出回路R1およびスイツチ素子SWが上記定電圧回路６
に直列に挿入されることによつて、付加されている。[Embodiment] An embodiment of the configuration of the low concentration gas analyzer of the present invention will be described with reference to the drawings. 1 is a solid electrolyte plate having ion conductivity, for example, made of stabilized zirconia having ion conductivity of oxygen gas, 2A and 2B are porous electrodes made of platinum formed on both surfaces of the solid electrolyte plate 1, and 3 is Solid electrolyte 1
A cap having a gas diffusion limiting hole 5 sealed on one side thereof so as to cover the electrode 2A on that side and form a gas diffusion chamber 4, E is a fixed gap between the two electrodes 2A and 2B. A constant voltage source for applying a voltage, 6 is a constant voltage circuit thereof, and 7 is a current limiting circuit added to the constant voltage circuit 6. The illustrated current limiting circuit 7 is one example thereof. Q 1 is an amplifier, Q 2 is a determination circuit, R 2 , R 3 , R 4 and R 5 are amplification resistors, R 1 is a current detection resistor,
SW is a switch element. In the current limiting circuit 7, the current detection circuit R 1 and the switch element SW are the constant voltage circuit 6 described above.
Are added by being inserted in series.
いま、酸素を排除した雰囲気で行つていた部品の加工が
完了し、その部品を加工室から搬出すると、加工室には
大気が侵入し、その中に設置されている低濃度用ガスセ
ンサは高濃度の酸素に触れることとなつて、センサの出
力電流は印加している監視電圧における最高の電流値ま
で増加しようとするが、電流制限回路７が付加されてい
るこにより、それよりもかなり低い電流値、例えば104p
pm酸素濃度に対応する電流値に達すると、スイツチ素子
SWは開となり、ガスセンサへの給電は停止される。こう
して、固体電解質板１に、酸素の高濃度雰囲気に曝され
たときに流れるであろう大電流が流れることは回避され
る。Now, when the processing of a part that had been carried out in an atmosphere where oxygen is excluded is completed and the part is taken out of the processing room, the atmosphere enters the processing room and the low concentration gas sensor installed in it By touching the concentration of oxygen, the output current of the sensor tries to increase to the maximum current value of the applied monitoring voltage, but it is considerably lower than that due to the addition of the current limiting circuit 7. Current value, for example 10 4 p
When the current value corresponding to the pm oxygen concentration is reached, the switch element
SW is opened and power supply to the gas sensor is stopped. In this way, it is possible to prevent a large current from flowing through the solid electrolyte plate 1 that would flow when exposed to an atmosphere of high oxygen concentration.
上記の電流制限回路７の実施例としては、ガスセンサの
出力電流値がある値に達すると、給電が停止される場合
を示したが、給電を停止することなく、上記のある値に
達するとそれ以上には電流が増加しないような回路とし
てもよい。As an example of the current limiting circuit 7 described above, the case where the power supply is stopped when the output current value of the gas sensor reaches a certain value has been shown, but when the certain value is reached without stopping the power supply, The circuit may be such that the current does not increase.
なお、上記の例の製造加工において、被加工部品を加工
室内にセツトし、加工室内が窒素ガスで充分に置換され
るまでの監視を必要とする場合には、この考案の低濃度
用ガス分析計とともに高濃度用の分析計をも併設してお
くとよい。In the manufacturing process of the above example, when it is necessary to set the parts to be processed in the processing chamber and monitor the processing chamber until it is sufficiently replaced with nitrogen gas, the low concentration gas analysis of the present invention It is advisable to install an analyzer for high concentration together with the meter.
［考案の効果］ この考案の低濃度用ガス分析計によれば、ガスセンサの
定電圧回路に電流制限回路を付加したことにより、ガス
センサがその使用範囲以上の高濃度雰囲気に曝されて
も、出力電流値はその高濃度に対応する大電流値に達す
る前にセンサへの給電が停止されるか、またはある電流
値までに制限されるので、固体電解質に大電流が流れる
ことから回避され、それの劣化が速められることを防止
することができる。[Advantages of the Invention] According to the low concentration gas analyzer of the present invention, by adding the current limiting circuit to the constant voltage circuit of the gas sensor, even if the gas sensor is exposed to a high concentration atmosphere beyond its use range, the output The current value is either de-energized before reaching the high current value corresponding to its high concentration, or is limited to a certain current value, so that it is avoided from the high current flowing through the solid electrolyte, Can be prevented from being accelerated.
図面はこの考案の低濃度用ガス分析計の実施例を示す回
路図を含む側面断面図である。 1;固体電解質板、2A、2B;多孔質電極、3;キヤツプ、4;
ガス拡散室、5;ガス拡散制限孔、6;定電圧回路、7;電流
制限回路、E;定電圧源、R1；電流検出抵抗、R2、R3、
R4、R5；増幅用抵抗、Q1；増幅器、Q2；判定回路、SW;
スイツチ素子。The drawing is a side sectional view including a circuit diagram showing an embodiment of the low concentration gas analyzer of the present invention. 1; solid electrolyte plate, 2A, 2B; porous electrode, 3; cap, 4;
Gas diffusion chamber, 5; Gas diffusion limiting hole, 6; Constant voltage circuit, 7; Current limiting circuit, E; Constant voltage source, R 1 ; Current detection resistor, R 2 , R 3 ,
R 4 , R 5 ; Amplification resistor, Q 1 ; Amplifier, Q 2 ; Judgment circuit, SW;
Switch element.
Claims (1)
質板の両面に多孔質電極を形成し、その片面に、その面
の電極を覆つてガス拡散室を形成するように、ガス拡散
制限孔を有するキヤツプを封着してなる限界電流式低濃
度用ガスセンサにおいて、上記電極間に電圧を印加する
定電圧回路に、出力電流をある電流値までに制限する電
流制限回路を付加してなる低濃度用ガス分析計。1. A gas diffusion limiting hole such that a porous electrode is formed on both surfaces of a solid electrolyte plate having ion conductivity of a predetermined gas, and a gas diffusion chamber is formed on one surface of the solid electrode plate by covering the electrode on that surface. In a limiting current type low concentration gas sensor having a cap sealed with a cap, a constant voltage circuit for applying a voltage between the electrodes is added with a current limiting circuit for limiting an output current to a certain current value. Gas analyzer for concentration.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1988146333U JPH0648409Y2 (en) | 1988-11-09 | 1988-11-09 | Low concentration gas analyzer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1988146333U JPH0648409Y2 (en) | 1988-11-09 | 1988-11-09 | Low concentration gas analyzer |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0295855U JPH0295855U (en) | 1990-07-31 |
| JPH0648409Y2 true JPH0648409Y2 (en) | 1994-12-12 |
Family
ID=31415721
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1988146333U Expired - Lifetime JPH0648409Y2 (en) | 1988-11-09 | 1988-11-09 | Low concentration gas analyzer |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0648409Y2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4643459B2 (en) * | 2006-01-26 | 2011-03-02 | 日本特殊陶業株式会社 | Sensor control device, sensor unit |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60219547A (en) * | 1984-04-16 | 1985-11-02 | Nissan Motor Co Ltd | Oxygen concentration detection apparatus |
| JPS61213664A (en) * | 1985-03-19 | 1986-09-22 | Honda Motor Co Ltd | Oxygen concentration detector |
| JPS61280560A (en) * | 1985-06-06 | 1986-12-11 | Fujikura Ltd | Method for measuring concentration of oxygen |
| JPS62115243A (en) * | 1985-11-13 | 1987-05-26 | Q P Corp | Packed spherical jelly food and production thereof |
| JPS62140502A (en) * | 1985-12-14 | 1987-06-24 | Nec Corp | Drop-in isolator |
| JPH0672863B2 (en) * | 1986-02-25 | 1994-09-14 | 本田技研工業株式会社 | Oxygen concentration detector |
| JPS62278443A (en) * | 1986-05-28 | 1987-12-03 | Nissan Motor Co Ltd | Air/fuel ratio measuring apparatus |
-
1988
- 1988-11-09 JP JP1988146333U patent/JPH0648409Y2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0295855U (en) | 1990-07-31 |
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