JPH02114167A - Gas concentration sensor having deterioration diagnosing function and method for diagnosing its deterioration - Google Patents
Gas concentration sensor having deterioration diagnosing function and method for diagnosing its deteriorationInfo
- Publication number
- JPH02114167A JPH02114167A JP63267882A JP26788288A JPH02114167A JP H02114167 A JPH02114167 A JP H02114167A JP 63267882 A JP63267882 A JP 63267882A JP 26788288 A JP26788288 A JP 26788288A JP H02114167 A JPH02114167 A JP H02114167A
- Authority
- JP
- Japan
- Prior art keywords
- electrode
- current
- deterioration
- gas concentration
- voltage
- 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
- 230000006866 deterioration Effects 0.000 title claims abstract description 33
- 238000000034 method Methods 0.000 title claims description 10
- 230000007423 decrease Effects 0.000 claims abstract description 11
- 238000009792 diffusion process Methods 0.000 claims abstract description 8
- 238000003745 diagnosis Methods 0.000 claims description 13
- 238000012544 monitoring process Methods 0.000 claims description 12
- 239000007784 solid electrolyte Substances 0.000 claims description 4
- 238000005086 pumping Methods 0.000 abstract 1
- 239000007789 gas Substances 0.000 description 31
- 150000002500 ions Chemical class 0.000 description 13
- 239000010416 ion conductor Substances 0.000 description 7
- 238000010586 diagram Methods 0.000 description 4
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 3
- 239000001301 oxygen Substances 0.000 description 3
- 229910052760 oxygen Inorganic materials 0.000 description 3
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 description 2
- 230000003247 decreasing effect Effects 0.000 description 2
- 229910001882 dioxygen Inorganic materials 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000000737 periodic effect Effects 0.000 description 2
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 2
- 229910002076 stabilized zirconia Inorganic materials 0.000 description 2
- 239000000969 carrier Substances 0.000 description 1
- 229910052697 platinum Inorganic materials 0.000 description 1
Landscapes
- Measuring Oxygen Concentration In Cells (AREA)
Abstract
Description
【発明の詳細な説明】
［産業上の利用分野］
この発明は、固体電解質よりなるイオン伝導板の両面に
多孔質電極が形成され、その一方の面に、ガス拡散孔と
内部室とを有するキャップが、上記一方の而の多孔質電
極を覆って被せられたガス濃度センサの上記電極間にあ
る電圧を印加すると、ある電圧の範囲内では電圧を上昇
させても得られる出力電流は一定であり、その出力電流
はセンサの外部雰囲気の所定のガスの濃度とある対応関
係があることを利用して所定ガス濃度を検出する、いわ
ゆる限界電流式ガス濃度センサにおいて、固体電解質よ
りなるイオン伝導板の劣化の度合を常時検出することが
できる劣化診断機能を有するガス濃度センサとその劣化
診断方法に関するものである。[Detailed Description of the Invention] [Industrial Application Field] This invention provides an ion conductive plate made of a solid electrolyte, in which porous electrodes are formed on both sides, and one side thereof has gas diffusion holes and an internal chamber. When a certain voltage is applied between the electrodes of the gas concentration sensor with the cap covering one of the porous electrodes, the output current obtained is constant within a certain voltage range even if the voltage is increased. In a so-called limiting current type gas concentration sensor, which detects a predetermined gas concentration by utilizing the fact that its output current has a certain correspondence with the concentration of a predetermined gas in the external atmosphere of the sensor, an ion conductive plate made of a solid electrolyte is used. The present invention relates to a gas concentration sensor having a deterioration diagnosis function that can constantly detect the degree of deterioration of a gas concentration sensor, and a deterioration diagnosis method thereof.
［従来の技術］
限界電流式ガス濃度センサとしては、例えば固体電解質
のイオン伝導体として安定化ジルコニアを使用した酸素
センサが従来から知られている。[Prior Art] As a limiting current type gas concentration sensor, for example, an oxygen sensor using stabilized zirconia as an ion conductor in a solid electrolyte has been known.
その１例を第４図を参照して説明すると、４Ｉは安定化
ジルコニアよりなるイオン伝導板、４２、４３はイオン
伝導板４１０両面に形成された例えば白金よりなる多孔
質電極、４６はイオン伝導板４１の片面に、その面の電
極４２を覆って被せられたキャップで、それには内部室
４７と、キャップ４６の外部と前記内部室４７とを連通
ずるガス拡散孔４８とが設けられたものである。なお、
図中Ｅは電極４２．４３間にある一定の監視電圧を与え
る定電圧源、Ｖ、Ａは電極４２．４３間に印加される電
圧を測定する電圧計およびそれらの間を流れる電流を測
定する電流計である。One example will be explained with reference to FIG. 4. 4I is an ion-conducting plate made of stabilized zirconia, 42 and 43 are porous electrodes made of platinum, for example, formed on both sides of the ion-conducting plate 410, and 46 is an ion-conducting plate. A cap that is placed on one side of a plate 41, covering the electrode 42 on that side, and is provided with an internal chamber 47 and a gas diffusion hole 48 that communicates the outside of the cap 46 with the internal chamber 47. It is. In addition,
In the figure, E is a constant voltage source that provides a certain monitoring voltage between electrodes 42 and 43, V and A are voltmeters that measure the voltage applied between electrodes 42 and 43, and the current that flows between them. It is an ammeter.
いまキャップ４６内の内部室４７の雰囲気をガス拡散孔
４８を通して外部雰囲気例えば酸素ガスを含む雰囲気と
同じ状態に置き、多孔質電極４２．４３間に電圧Ｖをか
けると、イオン伝導板４Ｉを通して酸素イオンが移動し
、このイオンをキャリアとする電流■が流れる （第５
図参照）。その電圧Ｖを次第に上昇させていくと、それ
にほぼ比例して電流ｒも増加する （第５図の曲線Ｃ）
が、さらに電圧Ｖを上昇させていくと、ある電圧の範囲
内では電圧を上昇させても電流は増加しない領域（第５
図の曲ＩｊｌＢ）か存在する。この領域の電流を限界電
流と呼んでおり、その電流の大きさはガス濃度と対応関
係があることから、その電流値を測定すればガス濃度を
求めることができる。第５図は種々の酸素ガス濃度にお
ける限界電流特性を示している。Now, when the atmosphere in the internal chamber 47 in the cap 46 is made to be the same as the external atmosphere, for example, an atmosphere containing oxygen gas, through the gas diffusion hole 48, and a voltage V is applied between the porous electrodes 42 and 43, oxygen is introduced through the ion conductive plate 4I. Ions move, and a current ■ flows with these ions as carriers (Chapter 5)
(see figure). When the voltage V is gradually increased, the current r also increases almost in proportion to it (curve C in Figure 5).
However, as the voltage V is further increased, the current does not increase even if the voltage is increased within a certain voltage range (fifth
The song IjlB) in the figure exists. The current in this region is called a limiting current, and since the magnitude of the current has a correspondence with the gas concentration, the gas concentration can be determined by measuring the current value. FIG. 5 shows the limiting current characteristics at various oxygen gas concentrations.
第５図において、測定すべきガス濃度範囲の各限界電流
領域に共通するある一定の電圧を選び、これを監視電圧
Ｖｓとしてガス濃度センサに印加している。ところがイ
オン伝導体である安定化ノルコニアが劣化してくると、
曲線Ｃの傾斜が寝てきて破線で示される曲線ＣＩとなっ
て、限界電流領域が狭くなり、監視電圧Ｖｓがいままで
は限界電流領域に懸かっていたにもかかわらずその領域
に懸からなくなって、曲線ＣＩに交叉するようになり、
所定のガス濃度が対応する限界電流値よりも小さい電流
値が測定されるようになる。もしイオン伝導体が劣化し
ているこ七に気付かなければ、その電流値を限界電流値
として読み取り、誤ったガスａ変を求めてしまうことに
なる。In FIG. 5, a certain voltage common to each limiting current region of the gas concentration range to be measured is selected and applied to the gas concentration sensor as the monitoring voltage Vs. However, as stabilized norconia, an ionic conductor, deteriorates,
The slope of the curve C has decreased and it becomes the curve CI shown by the broken line, and the critical current region has become narrower, and although the monitoring voltage Vs used to be in the critical current region, it no longer hangs in that region. , now intersects the curve CI,
A current value smaller than the limiting current value to which a given gas concentration corresponds will be measured. If one does not notice that the ionic conductor has deteriorated, the current value will be read as the limiting current value and the gas a change will be determined incorrectly.
限界電流式酸素センサではある年限、例えば３年という
寿命を設定しているが、なんらかの原因でそれよりも早
く劣化か進んでしまうことがあるため、つぎのような劣
化診断方法が考えられている。すなわち、監視電圧ＶＳ
をあるガス濃度範囲で共通する限界電流領域内で周期的
にＶｓ”Ｖｓ間で変化させる方法である。このようにし
ておけば、もしイオン伝導体の劣化が進んで、曲線Ｃ１
の部分が周期的に変化させている監視電圧Ｖｓ、に交わ
るようになると、電流値の低下が検出されるので、それ
によって劣化の度合を知ることができる。Limiting current type oxygen sensors are set to have a lifespan of a certain year, for example 3 years, but for some reason they may deteriorate or progress faster than that, so the following deterioration diagnosis method has been considered. . That is, the monitoring voltage VS
This is a method in which the ion conductor is periodically changed between Vs and Vs within a common limiting current region within a certain gas concentration range.If this is done, if the deterioration of the ionic conductor progresses and the curve C1
When the portion intersects the periodically changing monitoring voltage Vs, a decrease in the current value is detected, and the degree of deterioration can be determined from this.
［発明が解決しようとする課題］
上記の方法によれば、低下した電流値が測定されれば劣
化の進んでいることを知ることができるが、電圧の変化
に対する電流の変化の応答に時間が掛かり、電圧０．Ｉ
Ｖの変化に対応する変化された電流を得るのに例えば５
分を要し、したがって周期的な電圧の変化量をＩＶとす
ると、それに対応する電流値に落ち着かせるまでにはか
なりの時間を要することとなる。そのような電流値に落
ち着く前に監視電圧は周期的に変化されてしまうと、電
流値も劣化に対応する電流値に低下する而にある電流値
に引き戻されることになり、正しい劣化の度合を知るこ
とは困難となる。かかることから正確に劣化の度合を知
るため？こは、電圧変化のサイクルに長時ｎ１を掛ける
必要があり、なんらかの原因で急速に劣化が進行しても
、それを早急に知ることはできない。[Problems to be Solved by the Invention] According to the above method, it is possible to know that deterioration is proceeding by measuring a decreased current value, but it takes time to respond to a change in current to a change in voltage. applied, voltage 0. I
For example, 5 to obtain a changed current corresponding to a change in V.
Therefore, if the amount of periodic voltage change is IV, it will take a considerable amount of time to settle down to the corresponding current value. If the monitoring voltage is changed periodically before it settles to such a current value, the current value will also drop to the current value corresponding to the deterioration, but will be pulled back to a certain current value, making it difficult to determine the correct degree of deterioration. It becomes difficult to know. Is it possible to accurately determine the degree of deterioration from this? In this case, it is necessary to multiply the voltage change cycle by n1 for a long time, and even if deterioration progresses rapidly for some reason, it cannot be known immediately.
［課題を解決するための手段］
この発明は、上記の方法の応答に長時間を要する問題を
排除して、イオン伝導体に急激な劣化が生じても直ちに
それを検出することができるようにしたものであって、
イオン伝導板の両面に形成された多孔質電極のいずれか
一方の電極を主電極と補助電極とからなるものとし、主
電極には監視電圧を印加し、補助電極にはそれより低い
電圧を印加して、補助電極回路の出力電流の低下により
センサの劣化の度合を検出するようにしたものである。[Means for Solving the Problems] The present invention eliminates the problem of the above-mentioned method requiring a long response time, and makes it possible to immediately detect rapid deterioration in an ion conductor. was made,
Either one of the porous electrodes formed on both sides of the ion conductive plate is made up of a main electrode and an auxiliary electrode, and a monitoring voltage is applied to the main electrode, and a lower voltage is applied to the auxiliary electrode. In this way, the degree of deterioration of the sensor is detected based on a decrease in the output current of the auxiliary electrode circuit.
［作用］
上記の構成において、補助電極に印加される電圧も主電
極に印加される電圧と同様に限界電流領域にあるとすれ
ば、その各電極に流れる電流は各電極の面積に比例した
大きさとなり、それらの電流の和が所定のガス濃度に対
応する限界電流値となる。ここでガス濃度センサのイオ
ン伝導板の劣化か進行してくると、まず補助電極の印加
電圧が限界電流領域から外れ、したがって補助電極の出
力電流は減少する。この場合でも、イオン伝導板を通し
てイオン化された所定のガスが移行するボンピング作用
はセンサのガス拡散孔の大きさによって決定されるので
、補助電極の電流の減少があっても、その分、主電極の
電流が増加して、それらの電流の和は変化しない。[Function] In the above configuration, if the voltage applied to the auxiliary electrode is also in the limiting current region like the voltage applied to the main electrode, the current flowing through each electrode will be large in proportion to the area of each electrode. The sum of these currents becomes the limiting current value corresponding to a predetermined gas concentration. As the ion conductive plate of the gas concentration sensor progresses, the voltage applied to the auxiliary electrode first deviates from the limiting current range, and the output current of the auxiliary electrode decreases. Even in this case, the bombing effect in which a predetermined ionized gas moves through the ion-conducting plate is determined by the size of the gas diffusion hole in the sensor, so even if there is a decrease in the current in the auxiliary electrode, the main electrode increases, and the sum of those currents remains unchanged.
［実施例］
第１図および第２図はこの発明のガス濃度センサの異な
る実施例を示している。第１図において、１はイオン伝
導板、２および３はイオン伝導板ｉの両面Ｉこ形成され
た多孔質電極であって、その−方の電極２は主電極４お
よび補助電極５からなっている。６は上記の一方の電極
２を覆ってイオン伝導板ｌの片面に被せられたキャップ
で、これには内部室７およびこの内部室７とキャップ６
の外部とを連通ずるガス拡散孔８が設けられている。[Embodiments] FIGS. 1 and 2 show different embodiments of the gas concentration sensor of the present invention. In FIG. 1, 1 is an ion-conducting plate, 2 and 3 are porous electrodes formed on both sides of the ion-conducting plate i, and the negative electrode 2 consists of a main electrode 4 and an auxiliary electrode 5. There is. Reference numeral 6 denotes a cap that is placed on one side of the ion conductive plate l, covering one of the electrodes 2, and includes an internal chamber 7 and an internal chamber 7 and the cap 6.
A gas diffusion hole 8 communicating with the outside is provided.
Ｅｌは一方の電極２の主電極４と他方の電極３との間に
ある電圧を印加する定電圧源、Ｅ、は一方の電極２の補
助電極５と他方の電極３との間にある一定の電圧を印加
する定電圧源、Ｖｌ、■２はそれらの間の電圧を測定す
る電圧計、ＡＩ Ａｔはそれらの間の電流を測定する電
流計、Ａ、は上記電流の和を測定する電流計である。El is a constant voltage source that applies a voltage between the main electrode 4 of one electrode 2 and the other electrode 3, and E is a constant voltage source that applies a voltage between the auxiliary electrode 5 of one electrode 2 and the other electrode 3. 2 is a voltmeter that measures the voltage between them, AI At is an ammeter that measures the current between them, and A is the current that measures the sum of the above currents. It is a total.
つぎに第３図に示すように、主電極４と他方の電極３と
の間に監視電圧Ｖｓを印加し、補助電極５と他方の電極
３との間に低い電圧Ｖｔ （劣化診断電圧）を印加す
ると、電流計Ａ、では電流■が、電流計Ａｖでは電流■
、が測定され、それらの電流の和！。か電流計Ａ。で測
定される。なお第３図において、曲線Ｆ。Ｇｏはこの実
施例の限界電流特性曲線であって、Ｆｏはその限界電流
領域、Ｇ、はその領域に達する前の電圧電流特性である
。また曲線Ｆ、Ｇ、および曲線ＰｔＧｔは上記と同じく
主電極４と他方の電極３との間のおよび補助電極５と他
方の電極３との間の限界電流特性を示す曲線である。Next, as shown in FIG. 3, a monitoring voltage Vs is applied between the main electrode 4 and the other electrode 3, and a low voltage Vt (deterioration diagnosis voltage) is applied between the auxiliary electrode 5 and the other electrode 3. When voltage is applied, ammeter A produces a current ■, and ammeter Av produces a current ■
, is measured and the sum of their currents! . Or ammeter A. It is measured in In addition, in FIG. 3, curve F. Go is the limiting current characteristic curve of this embodiment, Fo is its limiting current region, and G is the voltage-current characteristic before reaching that region. Further, curves F, G, and curve PtGt are curves showing the limiting current characteristics between the main electrode 4 and the other electrode 3 and between the auxiliary electrode 5 and the other electrode 3, as described above.
イオン伝導板１が劣化してくると、補助電極回路の曲線
Ｇｔの部分が次第に寝てきて、その曲線部分が劣化診断
電圧Ｖｔと交叉するようになる。As the ion conductive plate 1 deteriorates, the portion of the curve Gt of the auxiliary electrode circuit gradually declines, and the curve portion comes to intersect with the deterioration diagnosis voltage Vt.
そうすると、電流計Ａ、に現れる電流は■、より小さく
なる。その小さくなった分だけ電流計ＡＩに現れる電流
は最初の電流ｒｌより増加し、電流計Ａ。に現れる電流
はＩ。で最初の電流値と変わらず、所定ガス濃度に対応
する値が示されたままである。かくして電流値■、の低
下からセンサのイオン伝導体１の劣化を知ることができ
る。Then, the current appearing on ammeter A becomes smaller than ■. The current appearing on the ammeter AI increases by the amount that it becomes smaller than the initial current rl, and the current appears on the ammeter A. The current appearing at is I. The value corresponding to the predetermined gas concentration remains unchanged from the initial current value. Thus, the deterioration of the ion conductor 1 of the sensor can be detected from the decrease in the current value (2).
第２図はこの発明のもう１つの実施例を示し、第１図の
場合と反対に、他方の電極３を主電極４および補助電極
５からなるものとしている。この場合の劣化診断方法も
第１図の場合と同様であるので、その説明を省略する。FIG. 2 shows another embodiment of the invention, in which, contrary to the case in FIG. 1, the other electrode 3 consists of a main electrode 4 and an auxiliary electrode 5. The deterioration diagnosis method in this case is also the same as in the case of FIG. 1, so its explanation will be omitted.
なお第１図、第２図の実施例では、イオン伝導板１のい
ずれか一方の多孔質電極２または３を主電極４および補
助電極５からなるものとした場合を示したが、両方の電
極をそのようにしてもよいことは勿論である。In the embodiments shown in FIGS. 1 and 2, the porous electrode 2 or 3 on one of the ion conductive plates 1 is composed of the main electrode 4 and the auxiliary electrode 5. Of course, it is also possible to do so.
さらに補助電極５の大きさとしては、片面の全電極面積
の５〜６０％程度とすることが望ましい。Further, the size of the auxiliary electrode 5 is preferably about 5 to 60% of the total electrode area on one side.
５％よりも小さい電極とすると、補助電極回路に流れる
電流■、が小さくなり過ぎて、劣化による電流の減少が
読み取りにくくなるためであり、その反対に６０％以上
となると、劣化が進んできて補助電極回路の電流の減少
分が大きくなると、その分だけ増加すべき電流を主電極
の面積では負担しきれなくなって、電流１．、ｒ、の和
は■。とならなくなり、所定ガス濃度との対応関係がな
くなるからである。If the electrode is smaller than 5%, the current flowing through the auxiliary electrode circuit becomes too small, making it difficult to read the decrease in current due to deterioration.On the other hand, if it is 60% or more, the deterioration has progressed. When the amount of decrease in current in the auxiliary electrode circuit increases, the area of the main electrode can no longer bear the increased current by that amount, and the current 1. The sum of , r, is ■. This is because there is no correspondence with the predetermined gas concentration.
［発明の効果］
以上のように、この発明のガス濃度センサおよびその劣
化診断方法によれば、イオン伝導板のいずれか一方の面
の多孔質電極を主電極と補助電極とからなる乙のとし、
これに常時監視電圧とそれよりも低い劣化診断電圧をそ
れぞれ印加しておき、かつそれらは一定の電圧としてお
くので、センサのイオン伝導板の劣化の進行は補助電極
回路の出力電流の減少となって、常に即時に検出するこ
とができ、従来のような電圧を周期的に変化させるため
の出力電流の応答の遅れはなく、さらに劣化診断電圧が
限界電流領域から外れると否とにかかわらず、所定のガ
ス濃度に対応したセンサの出力電流を常時読み取ること
ができる。[Effects of the Invention] As described above, according to the gas concentration sensor and its deterioration diagnosis method of the present invention, the porous electrode on either side of the ion conductive plate can be used as the main electrode and the auxiliary electrode. ,
Since a constant monitoring voltage and a lower deterioration diagnosis voltage are applied to this, and these voltages are kept constant, the progress of deterioration of the ion conductive plate of the sensor will cause a decrease in the output current of the auxiliary electrode circuit. Therefore, it can always be detected immediately, there is no delay in output current response due to periodic changes in voltage, and even if the deterioration diagnosis voltage goes out of the limit current range, The output current of the sensor corresponding to a predetermined gas concentration can be read at all times.
第１図および第２図はこの発明の劣化診断機能を有する
ガス濃度センサの異なる実施例を示す回路図を含む側面
断面図、第３図は萌記センサを使用して、この発明の劣
化診断方法を説明するための限界電流特性曲線図、第４
図および第５図は従来のガス濃度センサの実施例を示す
回路図を含む側面断面図および限界電流特性曲線図であ
る。
１．４１．イオン伝導板、２．３．４２．４３；多孔質
電極、４：主電極、５：補助電極、６．４６；キャップ
、７．４７；内部室、８．４８：ガス拡散孔、Ｅ、Ｅ、
Ｅ、、定電圧源、Ｖ、Ｖ、。
■、；電圧計、Ａ、Ａｎ 、Ａ、 、Ａｔ ；電流計、
Ｖｓ：監視電圧、ｖＬ：劣化診断電圧、曲線Ｆ。
Ｇｏ；ガス濃度センサの限界電流特性曲線、曲線Ｆ、Ｇ
、、主電極回路のセンサ部分の限界電流特性曲線、曲線
Ｆ、ｃｔ ；補助電極回路のセンサ部分の限界電流特性
曲線、Ｐ、、Ｆ、、Ｆ、；上記曲線のそれぞれの限界電
流領域、Ｇ、、Ｇ、Ｇ２：上記曲線のそれぞれの限界電
流領域に達する前の電圧電流特性曲線、Ｉｏ、Ｉｔ、Ｉ
ｔ：上記曲線のそれぞれの限界電流値、曲線ＢＣ，限界
電流特性曲線、Ｂ：限界電流領域、ＣＩ：劣化が進行し
た限界電流特性曲線、Ｖｓ、；周期的に変化された監視
電圧。1 and 2 are side sectional views including circuit diagrams showing different embodiments of the gas concentration sensor having a deterioration diagnosis function of the present invention, and FIG. 3 is a deterioration diagnosis of the present invention using the Moeki sensor. Limiting current characteristic curve diagram for explaining the method, 4th
5 and 5 are a side sectional view including a circuit diagram and a limiting current characteristic curve diagram showing an example of a conventional gas concentration sensor. 1.41. Ion conductive plate, 2.3.42.43; Porous electrode, 4: Main electrode, 5: Auxiliary electrode, 6.46; Cap, 7.47; Internal chamber, 8.48: Gas diffusion hole, E, E ,
E, , constant voltage source, V, V,. ■、; Voltmeter, A, An, A, , At; Ammeter,
Vs: monitoring voltage, vL: deterioration diagnosis voltage, curve F. Go: Limiting current characteristic curve of gas concentration sensor, curves F and G
,,Limiting current characteristic curve of the sensor part of the main electrode circuit, curve F, ct;Limiting current characteristic curve of the sensor part of the auxiliary electrode circuit, P,,F,,F,;Limiting current area of each of the above curves, G , , G, G2: voltage-current characteristic curves before reaching the respective limiting current regions of the above curves, Io, It, I
t: limit current value of each of the above curves, curve BC, limit current characteristic curve, B: limit current region, CI: limit current characteristic curve with advanced deterioration, Vs: periodically changed monitoring voltage.
Claims (2)
電極が形成され、その一方の面に、ガス拡散孔と内部室
とを有するキャップが、上記一方の面の多孔質電極を覆
つて被せられているガス濃度センサにおいて、いずれか
一方の面の多孔質電極は主電極と補助電極とからなるこ
とを特徴とする劣化診断機能を有するガス濃度センサ。(1) Porous electrodes are formed on both sides of an ion conductive plate made of a solid electrolyte, and a cap having gas diffusion holes and an internal chamber is placed on one side to cover the porous electrode on one side. 1. A gas concentration sensor having a deterioration diagnosis function, characterized in that the porous electrode on either side consists of a main electrode and an auxiliary electrode.
には監視電圧を印加し、補助電圧にはそれより低い電圧
を印加して、補助電極回路の出力電流の低下によりセン
サの劣化の度合を検出することを特徴とするガス濃度セ
ンサの劣化診断方法。(2) In the gas concentration sensor according to claim 1, a monitoring voltage is applied to the main electrode, and a lower voltage is applied to the auxiliary voltage, so that the degree of deterioration of the sensor is reduced due to a decrease in the output current of the auxiliary electrode circuit. A method for diagnosing deterioration of a gas concentration sensor, characterized by detecting.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63267882A JPH02114167A (en) | 1988-10-24 | 1988-10-24 | Gas concentration sensor having deterioration diagnosing function and method for diagnosing its deterioration |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63267882A JPH02114167A (en) | 1988-10-24 | 1988-10-24 | Gas concentration sensor having deterioration diagnosing function and method for diagnosing its deterioration |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH02114167A true JPH02114167A (en) | 1990-04-26 |
Family
ID=17450941
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63267882A Pending JPH02114167A (en) | 1988-10-24 | 1988-10-24 | Gas concentration sensor having deterioration diagnosing function and method for diagnosing its deterioration |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH02114167A (en) |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS57192850A (en) * | 1981-05-25 | 1982-11-27 | Toyota Central Res & Dev Lab Inc | Detecting device for limit current system oxygen concentration performing internal resistance compensation |
| JPS60218058A (en) * | 1984-04-14 | 1985-10-31 | Fujikura Ltd | Self-diagnosing method of oxygen sensor |
-
1988
- 1988-10-24 JP JP63267882A patent/JPH02114167A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS57192850A (en) * | 1981-05-25 | 1982-11-27 | Toyota Central Res & Dev Lab Inc | Detecting device for limit current system oxygen concentration performing internal resistance compensation |
| JPS60218058A (en) * | 1984-04-14 | 1985-10-31 | Fujikura Ltd | Self-diagnosing method of oxygen sensor |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US3691023A (en) | Method for polarographic measurement of oxygen partial pressure | |
| EP0152942B1 (en) | Device for detecting air-fuel ratio of mixture over wide range from below to above stoichiometric ratio | |
| US4490678A (en) | Method of and an apparatus for measuring ion concentrations in solutions | |
| EP0580206B1 (en) | Wide-range oxygen sensor | |
| EP0987546B1 (en) | Gas concentration sensing apparatus | |
| JPS5562349A (en) | Measuring method for air fuel ratio | |
| JPS634660B2 (en) | ||
| JPS6325300B2 (en) | ||
| US10036721B2 (en) | Method for operating a solid electrolyte sensor element containing a pump cell | |
| JPH09318594A (en) | Gas sensor and method for measuring quantity of specific component in gas to be measured | |
| JP3849678B2 (en) | Gas concentration measuring device | |
| US6312585B1 (en) | Method for determining oxidizable constituents in a gaseous mixture | |
| US5972200A (en) | Method for driving a wide range air to fuel ratio sensor | |
| JPH02114167A (en) | Gas concentration sensor having deterioration diagnosing function and method for diagnosing its deterioration | |
| US6214209B1 (en) | Method of measuring oxygen | |
| JP2001174436A (en) | Method and apparatus for measuring ion concentration | |
| CA1114018A (en) | Method for detecting the fouling of a membrane covered electrochemical cell | |
| JPS60218058A (en) | Self-diagnosing method of oxygen sensor | |
| US6084414A (en) | Testing for leakage currents in planar lambda probes | |
| JPH053909B2 (en) | ||
| JP3487990B2 (en) | Self-calibration type oxygen analysis method and device | |
| JPH01262460A (en) | Self-diagnosis method for deterioration of oxygen sensor | |
| Iasinski et al. | with Cyclic Voltammetry | |
| JPS57192850A (en) | Detecting device for limit current system oxygen concentration performing internal resistance compensation | |
| JP3561149B2 (en) | NOx gas concentration measurement method |