JPS5832156A - Sensor for concentration of specific substance - Google Patents
Sensor for concentration of specific substanceInfo
- Publication number
- JPS5832156A JPS5832156A JP56131100A JP13110081A JPS5832156A JP S5832156 A JPS5832156 A JP S5832156A JP 56131100 A JP56131100 A JP 56131100A JP 13110081 A JP13110081 A JP 13110081A JP S5832156 A JPS5832156 A JP S5832156A
- Authority
- JP
- Japan
- Prior art keywords
- concentration
- solid electrolyte
- oxygen
- film
- specific substance
- Prior art date
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Classifications
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- 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
- G01N27/26—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating electrochemical variables; by using electrolysis or electrophoresis
- G01N27/416—Systems
- G01N27/417—Systems using cells, i.e. more than one cell and probes with solid electrolytes
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- Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Health & Medical Sciences (AREA)
- Physics & Mathematics (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Molecular Biology (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Measuring Oxygen Concentration In Cells (AREA)
Abstract
Description
【発明の詳細な説明】 この発明は特定物質の濃度センサーに関する。[Detailed description of the invention] The present invention relates to a concentration sensor for a specific substance.
更に詳しくは固体電解質を利用した流体状の特定物質の
濃度センサーであって、標準ガスを必要とせず、高精度
、高正確度でかつ広い測寓範囲を有し、長寿会である特
定物質の濃度センサーに関する。More specifically, it is a fluid concentration sensor for specific substances that uses a solid electrolyte, does not require standard gas, has high precision, high accuracy, and has a wide measuring range. Regarding concentration sensors.
近年、ある種の固体電解質が高温雰囲気下において特定
物質を選択的にイオンとして伝導又は透過させる性質を
示すことが見出され、この性質を利用した種々の分析機
器、燃料電池等が知られている。ことに酸化ジルコニウ
ムに異原子価の酸化物を固溶した安定化ジルコニアを固
体電解質として用いた酸素の濃度センサーや酸素ポンプ
が実用化されている。これらのうち酸素濃度センサーは
、安定化ジルコニア膜の両面に白金や銀の多孔性電極を
設け、５００〜１０００℃の高温下で両面をそれぞれ異
なる酸素濃度（ＰＯ，とＰＯ２）の酸素を含む気体に接
触させると両電極間に
（式中、又は気体定数、Ｆはファラデ一定数、Ｔは測定
温度をそれぞれ示す）
からなる電位差Ｅが生じ、従っていずれかの濃度を一定
にしておけば酸素濃度の計測ができるという原理に基づ
いている。また、酸素ポンプ等は、上記電極間に電流を
外部から強制的に流せば電解により酸素を一方の面から
他力の面に移動できかつ移動量が電量に比例するという
原理に基づいている。他の固体電解質を用いた特定物質
の濃度センサーやポンプも同様な原理に基づいている。In recent years, it has been discovered that certain solid electrolytes exhibit the property of selectively conducting or permeating specific substances as ions in high-temperature atmospheres, and various analytical instruments, fuel cells, etc. that utilize this property have become known. There is. In particular, oxygen concentration sensors and oxygen pumps using stabilized zirconia, which is a solid solution of oxides of different valences in zirconium oxide, as solid electrolytes have been put into practical use. Among these, the oxygen concentration sensor has porous electrodes of platinum or silver on both sides of a stabilized zirconia membrane, and at high temperatures of 500 to 1000°C, each side is exposed to gas containing oxygen with different oxygen concentrations (PO, and PO2). When brought into contact with It is based on the principle that it is possible to measure Further, oxygen pumps and the like are based on the principle that if a current is forced to flow between the electrodes from the outside, oxygen can be moved from one side to the other side by electrolysis, and the amount of movement is proportional to the amount of electricity. Concentration sensors and pumps for specific substances that use other solid electrolytes are based on similar principles.
しかしながら上記のごとき特定物質の濃度センサーにお
いては、式（Ｉ）から明らかなように 出力電圧信号が
特定物質の濃度に対して対数目盛となり測定のダイナミ
ックレンジを広くできないのみならず濃度の大きい部分
で精度が悪いという欠点があった。さらに固体電解質の
片面には標準ガスを測定中連続して流しておく必要があ
り、例えば−素濃度を測定する際標準ガスとして空気を
用いると信頼性が乏しく、信頼できる標準ガスは測定中
多量に消費されるという欠点があった。However, in the above concentration sensor for a specific substance, as is clear from equation (I), the output voltage signal is on a logarithmic scale with respect to the concentration of the specific substance, which not only makes it impossible to widen the dynamic range of measurement, but also makes it impossible to widen the dynamic range of measurement. It had the disadvantage of poor accuracy. Furthermore, it is necessary to continuously flow a standard gas through one side of the solid electrolyte during measurement. The disadvantage was that it was consumed by
これに対し、酸化パラジウムを濃度センサー内に詰めて
標準ガスの代わりに用いた酸素濃度センサーが提案され
ている（米国特許第４０４５１１９号明細書）。しかし
この場合は確かに標準ガスは不要であるが、標準酸素濃
度を変化させることができず測定可能範囲が限定され、
酸化パラジウム自体の寿命にも問題がある。そしてやは
り出力信号が濃度に対して対数目盛となる欠点を有して
いる。On the other hand, an oxygen concentration sensor has been proposed in which palladium oxide is packed inside the sensor and used instead of the standard gas (US Pat. No. 4,045,119). However, in this case, although the standard gas is certainly unnecessary, the measurable range is limited because the standard oxygen concentration cannot be changed.
There is also a problem with the lifespan of palladium oxide itself. Again, this method has the disadvantage that the output signal is on a logarithmic scale with respect to concentration.
一方、これらの問題点に鑑み、細孔を有する２枚の固体
電解質を対向させて閉鎖空間を設け、一方の固体電解的
で内外面の電位差を検出し、この電位差に対抗する負帰
還電流を他方の固体電解質に供給して電解移動させ該負
帰還電流を測定して閉鎖室外面の特定物質（酸素）の濃
度を測定するセンサーが提案されている（ Ａｐｐｌ、
Ｐｈｙｓ 、 Ｌｅｔｔ、。On the other hand, in view of these problems, a closed space is created by placing two solid electrolytes with pores facing each other, and the potential difference between the inner and outer surfaces of one solid electrolyte is detected, and a negative feedback current is generated to counter this potential difference. A sensor has been proposed that measures the concentration of a specific substance (oxygen) on the outer surface of a closed chamber by supplying it to the other solid electrolyte and electrolytically moving it to measure the negative feedback current (Appl.
Phys, Lett.
ｐ、ｐ、 ８９←８９２． Ｖｏｊ、 ８ｇ、ｔｌｈ
６ 、 Ｉ Ｍａｒｃｈ（１９８１）１この提案によれ
ば、出力信号が特定物質の濃度に直線的に比例するため
測定範囲が広くとれ、さらに標準ガスを必裂としない利
点がある。しかし閉鎖空間から細孔を通して酸素と共存
ガスとを拡散によって排出しているため、共存するガス
の種類、ｍ成によって拡散速度が異なり」存ガスによる
酸素濃度測定値への影響が大で高精度、高正確度の測定
は困難である。そして、閉鎖空間は密閉されていないた
め汚染されかつそれによる誤差を生じる恐れがある。さ
らに、固定電解質に設けられた細孔の孔径は厳密を要し
、燃焼排ガス中等の酸素濃度測定において該細孔を詰め
てしまう恐れがあり賽用上の難点を有している。p, p, 89←892. Voj, 8g, tlh
6, I March (1981) 1 According to this proposal, since the output signal is linearly proportional to the concentration of the specific substance, the measurement range can be widened, and there is also the advantage that the standard gas is not necessarily required. However, since oxygen and coexisting gases are exhausted from a closed space through pores by diffusion, the diffusion rate varies depending on the type and composition of coexisting gases. , measurement with high accuracy is difficult. Furthermore, since the closed space is not sealed, there is a risk of contamination and resulting errors. Furthermore, the diameter of the pores provided in the fixed electrolyte must be exact, and there is a risk that the pores will be clogged when measuring the oxygen concentration of combustion exhaust gas, etc., which poses a practical problem.
この発明はこのような従来の濃度センサーの多くの欠点
を解消すべくなされたものであり、高精度、高正確度で
実用に適する特定物質の濃度セン量−を提供するもので
ある。この発明の発明者は鋭意研究の結果、二枚の固体
電解質膜と絶縁層により、特定物質の流動可能な密閉空
間を形成し、これら固体電解質Ｈｔｉ従来と異なる特定
の機能を与えることにより所望の濃度センサーを得、こ
の発明に到達した。The present invention has been made in order to eliminate many of the drawbacks of such conventional concentration sensors, and provides a highly accurate and highly accurate concentration sensor of a specific substance suitable for practical use. As a result of intensive research, the inventor of this invention formed a sealed space in which a specific substance can flow using two solid electrolyte membranes and an insulating layer, and by giving these solid electrolytes Hti specific functions different from conventional ones, the desired effect can be achieved. We obtained a concentration sensor and arrived at this invention.
かくしてこの発明によれば、対向する第１及び第２の固
体電解質膜と絶縁層により密閉された特定物質の流動可
能な空間を形成する本体、第１の固体電解質膜に設けら
れた特定物質を該ｉ！解質膜を通して継続的に電解移動
させる手段、第２の固体電解質膜に設けられた該固体電
解質膜の内外両面に接触する特定物質の濃度差に対応す
る電位差を検出し該電位差が一定の設定値となるように
負帰還電流を流して特定物質を電解移動させる制御手段
、及び上記負帰還電流の測定手段を備え、負帰還電流に
基づいて密閉された空間外の特定物質の濃度を測定でき
るよう構成してなる特定物質の濃度センサーが提供され
る。Thus, according to the present invention, the main body forms a space in which a specific substance can flow, which is sealed by the first and second solid electrolyte membranes facing each other and an insulating layer, and the specific substance provided in the first solid electrolyte membrane. That i! A means for continuously electrolytically moving through the electrolyte membrane, a means for detecting a potential difference corresponding to a concentration difference of a specific substance provided in a second solid electrolyte membrane that contacts both the inner and outer surfaces of the solid electrolyte membrane, and setting the potential difference to be constant. A control means for electrolytically moving a specific substance by flowing a negative feedback current so as to reach a certain value, and a means for measuring the negative feedback current, and the concentration of the specific substance outside the sealed space can be measured based on the negative feedback current. A concentration sensor for a specific substance configured as described above is provided.
この発明の濃度センサーは出力信号が測定対象の特定物
質の濃度に直線的に比例するため高精度、高正確度であ
り、測定範囲が大きくとれ有利である。そして標準ガス
を全く必要としない。さらに密閉空間内には純粋な酸素
のみが固体電解質を通して出入りするため共存ガスの影
響がなく、燃焼ガス中の酸素計測のように粉粒や煤煙に
よる汚染条件下に右いてもその影響をほとんど無視でき
畏寿命である。従って特定物質の連続モニターに好′適
である。The concentration sensor of the present invention has high precision and accuracy because the output signal is linearly proportional to the concentration of the specific substance to be measured, and is advantageous in that it has a wide measurement range. And no standard gas is required. Furthermore, since only pure oxygen enters and exits the sealed space through the solid electrolyte, there is no effect of coexisting gases, and even if the oxygen is measured in combustion gas under conditions of contamination with particles or soot, the effects are almost ignored. It has a long lifespan. Therefore, it is suitable for continuous monitoring of specific substances.
以下、添付の図面に従いこの発明の詳細な説明する。第
１図は、この発明の特定物質の濃度センサーの一具体例
である酸素濃度センサーの断面図を含む機能説明図であ
る。第１図において、＠１の固体電解質膜である安定化
ジルコニア膜（１）と第２の固体電解質膜である安定化
ジルコニア膜（２）は間隔（（至）で対向して位置して
おり、濃度センサ一本体はこれらと絶縁層（３）および
紙面の手前と奥に位置する絶縁層によって長方体状の密
閉空間（５）を形成している。それぞれの安定化ジルコ
ニア膜の内外両面には、白金からなる多孔性電極（４）
が密接して設けられている。第１の安定化ジルコニア膜
（１）には多孔性電極を通じて、特定物質である酸素を
強制的に電解移動させるための電解用直流電源（６）を
備えた回路が付設されている。、一方、第２の安定化ジ
ルコニア膜（２）には多孔性電極を通じて、内外両面の
酸素濃度差を検出し該電位差が一定の設定値となるよう
に自動的に負＋Ｉ！１還電流を流して酸素を電解移動さ
せる負帰還増幅器（７）、補助加電圧電源（８）、電極
電位差測定器（９）、Ｉ Ｒドロップ検出器ａＯ１負帰
還回路抵抗■、右よび等価抵抗調整用の可変抵抗（２）
からなる制御回路が付設されている。The present invention will now be described in detail with reference to the accompanying drawings. FIG. 1 is a functional explanatory diagram including a sectional view of an oxygen concentration sensor, which is a specific example of the specific substance concentration sensor of the present invention. In Figure 1, the stabilized zirconia membrane (1), which is the solid electrolyte membrane @1, and the stabilized zirconia membrane (2), which is the second solid electrolyte membrane, are located facing each other with an interval ((to)). , the concentration sensor body forms a rectangular closed space (5) with these, an insulating layer (3), and insulating layers located in the front and back of the page.The inner and outer surfaces of each stabilized zirconia film includes a porous electrode (4) made of platinum.
are placed closely together. The first stabilized zirconia membrane (1) is attached with a circuit equipped with an electrolytic DC power source (6) for forcibly electrolytically transferring oxygen, which is a specific substance, through a porous electrode. , on the other hand, the second stabilized zirconia membrane (2) uses a porous electrode to detect the difference in oxygen concentration between the inner and outer surfaces, and automatically adjusts the potential difference to a constant set value (negative +I!). Negative feedback amplifier (7) that electrolytically transfers oxygen by flowing a return current (7), auxiliary voltage supply (8), electrode potential difference measuring device (9), I R drop detector aO1 negative feedback circuit resistance ■, right and equivalent resistance Variable resistance for adjustment (2)
A control circuit consisting of is attached.
上記構成において、充分過料な定電流が電源（６）によ
り＠ｌの安定化ジルコニア膜（１）に供給され密閉空間
内のｍ累は該摸を通して電解移動され密閉空間外へ排出
される。In the above configuration, a sufficiently high constant current is supplied to the stabilized zirconia film (1) by the power supply (6), and the m particles in the closed space are electrolytically moved through the film and discharged out of the closed space.
Ｗ２図に密閉空間内での酸素濃度分布の種々のパターン
を示す。このように第１の安定化ジルコニア膜の内表面
濃度Ｃｏは電解によってゼロであり、第２の安定化ジル
コニア膜の内表面濃度をＣｉ（〆０）とするとある瞬間
（ｔＯ）では（Ａ）のような濃度勾配を生じる。第１の
安定化ジルコニア膜での電解だけを行なっている場合、
時間がｔ（１→ｔ１−”ｔ２”ｔｓと進行するとこれに
対応して濃度勾配は■−■−Ｃ）−（Ｄ）と変化し、時
間が無限大ｔｗとなると（Ｅ）となって密閉空間内の酸
素は完全に排出される。一方、第２の安定化ジルコニア
膜にセいては、外面（測定対象）の酸素濃度Ｃｓに対応
する表面電位、ｔｓと密閉空間内表面の酸素濃度Ｃｉに
対応する表面電位ｔ／ｉとの差（、Ｉｆ、−、／ｉ）を
検出し、これを一定の設定値〔補助加電圧電源（６）の
電圧！、に対応する〕に保持するため負帰還電流Ｉ（を
１７５２の安定化ジルコニア膜に流して酸素を電解移動
させる自動制御が行なわれている。Figure W2 shows various patterns of oxygen concentration distribution in a closed space. In this way, the inner surface concentration Co of the first stabilized zirconia film is zero due to electrolysis, and if the inner surface concentration of the second stabilized zirconia film is Ci (〆0), then at a certain moment (tO), (A) This results in a concentration gradient such as When only electrolysis is performed on the first stabilized zirconia membrane,
When time progresses as t(1→t1-"t2"ts), the concentration gradient changes as ■-■-C)-(D), and when time becomes infinite tw, it becomes (E). Oxygen in the closed space is completely exhausted. On the other hand, for the second stabilized zirconia film, there is a difference between the surface potential ts corresponding to the oxygen concentration Cs on the outer surface (measurement target) and the surface potential t/i corresponding to the oxygen concentration Ci on the inner surface of the closed space. (, If, -, /i) and set this to a certain set value [voltage of auxiliary voltage power supply (6)! In order to maintain a negative feedback current I (corresponding to
従って第１の安定化ジルコニア膜での電解移動によって
ＣＩが低下すると！五が低下するので）、−（）ｉ＋Ｊ
！ｉ）の値に差を生じ、Ｉｆが流れＣｓの酸素がＣｉに
供給される。そしてＬ／Ｓ！ −（、／Ｍ＋Ｌｌ！り４
Ｐｏで平衡しＨは動的平衡吠餓で一定となる。Therefore, if the CI decreases due to electrolytic migration in the first stabilized zirconia film! 5 decreases), -()i+J
! A difference occurs in the value of i), If flows and oxygen from Cs is supplied to Ci. And L/S! -(,/M+Ll!ri4
Equilibrium is established at Po, and H becomes constant due to dynamic equilibrium pressure.
この状譜で試料の酸素濃度Ｃ３が＋ａだけ増加すると、
Ｌ／、〉）ｉ十！１となりＩｆが増加゛し、Ｌｌ！ｉが
増加して第２の安定化ジルコニア膜の内面Ｃ１はＣｌ＋
ａ’となって平衡する。このときの密閉室内の濃度勾配
は（Ａ５のようになる。そしてＣＢ ＋ｃｆの濃度を保
つために電流１（が流れ、この値はこのときのＣ，に対
応する。逆にＣｓが−αだけ濃度低下すると前述と逆に
なってＣ１はＣ４−ｇ となりＩｆは減少して平衡す
る（濃度勾配（Ａ＃））。In this situation, when the oxygen concentration C3 of the sample increases by +a,
L/,〉)i ten! 1, If increases, and Ll! As i increases, the inner surface C1 of the second stabilized zirconia film becomes Cl+
a' and is in equilibrium. At this time, the concentration gradient in the sealed chamber is as shown in (A5). In order to maintain the concentration of CB When the concentration decreases, C1 becomes C4-g, which is the opposite of the above, and If decreases to reach equilibrium (concentration gradient (A#)).
すなわちＩｆは試料の酸素濃度Ｃｓに直線的に比例し、
ＩＩを電流計翰によって測定することによりＣｓを簡便
に検出することができる。な忽、制御回路中に設定した
電圧！、は、連続測定時に極端に低い濃度の試料が接触
した際、密閉室内の酸素濃度が極端に低下して測定不能
となることをさけるために組み入れたちのてあり％寮際
上の測定範囲を設定す葛ためのものである。従って電圧
Ｊ１を除去しても勿論測定可能である。そして、密閉室
内の酸素濃度が極端に低下した場合に右いては、適当な
切替えスイッチによって電解用直流電源の方向を逆に設
定し、第１の安定化ジルコニア膜を通して酸素を密閉空
間内へ導入する電解移動を行ない、これに対応するＩ（
を同様に電流計（支）で測定することによって試料濃度
を測定することができる。すｔ【わち、第１の固体電解
質膜における電解移動は排出反応であっても導入反応て
あっても測定可能であり、測定対象によって適宜９Ｊ替
えることも可能である。That is, If is linearly proportional to the oxygen concentration Cs of the sample,
Cs can be easily detected by measuring II with an ammeter. By the way, the voltage set in the control circuit! , has been incorporated to prevent the oxygen concentration in the closed room from extremely decreasing and making measurements impossible when a sample with an extremely low concentration comes into contact with the sample during continuous measurement. The setting is for kudzu. Therefore, it is of course possible to perform measurements even if the voltage J1 is removed. If the oxygen concentration in the sealed chamber is extremely low, the direction of the electrolytic DC power source is reversed using an appropriate changeover switch, and oxygen is introduced into the sealed space through the first stabilized zirconia membrane. The electrolytic transfer is carried out, and the corresponding I(
The sample concentration can be measured by similarly measuring with an ammeter (support). [That is, the electrolytic transfer in the first solid electrolyte membrane can be measured whether it is an exhaust reaction or an introduction reaction, and it is also possible to change 9 J as appropriate depending on the object to be measured.
なお、上記測定において可変抵抗亜は、予め第２の安定
化ジルコニア膜の内部抵抗Ｒと等価になるよう調整して
詔く必要がある。すなわち、第２の膜の内部抵抗Ｒがゼ
ロの場合はＩＲドロップ検出器ＱＯ及び可変抵抗（２）
は制御回路中下必要である。In addition, in the above measurement, it is necessary to adjust the variable resistance in advance so that it becomes equivalent to the internal resistance R of the second stabilized zirconia film. That is, when the internal resistance R of the second film is zero, the IR drop detector QO and the variable resistor (2)
is required in the control circuit.
そして実際の安定化ジルコニウムの８００℃における抵
抗は、厚み１〜２ｍｍで約１０〜６０Ｖ−程度であり、
厚みを０．１ ｍｍ程度まで薄くすると１−６Ω程度と
なるので固体電解質膜の成形方法や材質によっては無視
できる程度小さくすることも可能である。しかし、１０
０程度の抵抗があって負帰還電流■ｆが１００ｍＡ程度
流れると１ｖの電圧が、７１− （４ｉ ＋Ｊ！、 ）
に加えられＩｆの変化によって（９）及び（７）の入力
が変化することになり、高精度、高正確度の測定では小
さな内部抵抗も大きく影響することになるので、１！２
の固体電解質膜の抵抗ＲによるＩＲドロップは除去して
Ｊ！ｓ −Ｃｔ４ ＋１８）のみに関与するＩｆを求め
ることが好ましい。The actual resistance of stabilized zirconium at 800°C is about 10 to 60 V- at a thickness of 1 to 2 mm.
When the thickness is reduced to about 0.1 mm, it becomes about 1-6 Ω, so depending on the molding method and material of the solid electrolyte membrane, it is possible to make it negligible. However, 10
If there is a resistance of about 0 and a negative feedback current f of about 100 mA flows, a voltage of 1 V will be 71- (4i + J!, )
The inputs of (9) and (7) will change due to the change in If added to , and even a small internal resistance will have a large effect on high-precision, high-accuracy measurements, so 1!2
The IR drop due to the resistance R of the solid electrolyte membrane is removed and J! It is preferable to find If that is related only to s - Ct4 +18).
第１図の具体例においては可変抵抗＠によって適宜調整
できるＩＲドロップ補償回路が付設されている。すなわ
ち、内部抵抗Ｒは温度が一定ならばほぼ一定で予め計測
可能な量であるからＲと等価な抵抗Ｒ′を可変抵抗υに
よって制御回路中に設け、Ｉｆによる１ｆＲドロップ分
の電圧を入力抵抗の充分大きいＩ【χロツプ検出装置帥
に供給する。その出力を負帰還増幅器（７）に差動的に
結合し、（７）の出力がＬ／ｓ Ｇｊ ｉ ＋Ｊ！ａ
） ＋ Ｉ ｒＲ） −Ｉ （Ｒ’に対応するようにｆ
ｆ１ｆｆされている。これによってＩｆは、７ｇ −（
、Ｊ！ｔ ＋、７ａ）にのみ対応して流れる制御回路が
得られる。なお、ＲとＶは厳密に一致させる必要はない
。というのはわずかな差があっても設定電位が変化する
だけで出力の直線性には影響なく、既知濃度の標準ガス
で較正すれば計測上の誤差は除去できるからである。In the specific example shown in FIG. 1, an IR drop compensation circuit is provided which can be appropriately adjusted using a variable resistor. In other words, since the internal resistance R is almost constant if the temperature is constant and can be measured in advance, a resistance R' equivalent to R is provided in the control circuit using a variable resistor υ, and the voltage corresponding to the 1fR drop due to If is applied to the input resistance. A sufficiently large I[chi] is supplied to the lop detector. Its output is differentially coupled to a negative feedback amplifier (7), and the output of (7) is L/s Gj i +J! a
) + I rR) −I (f to correspond to R'
It has been f1ff. As a result, If becomes 7g −(
, J! A control circuit is obtained which flows only in response to t +, 7a). Note that R and V do not need to exactly match. This is because even if there is a slight difference, it only changes the set potential and does not affect the linearity of the output, and measurement errors can be removed by calibrating with a standard gas of known concentration.
この発明の固体電解質膜に用いる固体電解質としては、
通常この分野で公知の種々の固体電解質が使用できる。The solid electrolyte used in the solid electrolyte membrane of this invention is as follows:
A variety of solid electrolytes commonly known in the art can be used.
具体的な固体電解質としては、酸素イオン透過性の安定
化ジルコニア、トリア固溶体、セリア固溶体、酸化ビス
マス及びペロブスカイト型酸化物や、酸素イオン又は塩
素イオン透過性の塩化ストロンチウム／塩化カリウム／
ａｉ２化ストロンチウム固溶体、プロトン透過性のパラ
ジウム化合物等が挙げられる。なお、これ以外にイオン
伝導性ポリマー膜やイオン交換膜で選択性を有するもの
が使用可能である。従って、特定物質として酸素、塩素
、水素等の種々のガス状物質を選択的に測定することが
できる。なお、固体電解質膜の厚みは０．２〜１Ｏｎｏ
ｎ程度が適当である。Specific solid electrolytes include oxygen ion permeable stabilized zirconia, thoria solid solution, ceria solid solution, bismuth oxide and perovskite type oxides, and oxygen ion or chloride ion permeable strontium chloride/potassium chloride/
Examples include strontium ai2 oxide solid solution and proton-permeable palladium compounds. In addition, ion-conducting polymer membranes and ion-exchange membranes having selectivity can be used in addition to these. Therefore, various gaseous substances such as oxygen, chlorine, and hydrogen can be selectively measured as specific substances. The thickness of the solid electrolyte membrane is 0.2 to 1 mm.
Approximately n is appropriate.
この発明における密閉された特定物質の流動可能な空間
は、第１図に示したごとき密閉室状の空間に限定される
ものではない。例えば第８図に示すように第１及び第２
の固体電解質の内面の多孔性電極を隣接一体化し、該多
孔性電極の外表面のみを絶縁層で覆い該電極内の多孔質
空間を密閉空間として構成してもよい。この場合密閉空
間内容積が小さくなり応答速度が速くなる等、好ましい
場合がある。いずれにせよ、Ｉｆ１と第２の固体電解質
膜の間隔（ｄ）はせいぜいｉｍｍ程度で充分である。In the present invention, the sealed space in which the specific substance can flow is not limited to a sealed chamber-like space as shown in FIG. For example, as shown in FIG.
Porous electrodes on the inner surface of the solid electrolyte may be integrated adjacent to each other, and only the outer surface of the porous electrode may be covered with an insulating layer to form a porous space within the electrode as a closed space. In this case, the internal volume of the closed space becomes smaller and the response speed becomes faster, which may be preferable. In any case, it is sufficient for the distance (d) between If1 and the second solid electrolyte membrane to be approximately imm at most.
なお、密閉空間を固体電解質膜と共に構成する絶縁層と
しては耐熱鋼、酸化アルミニウム、白金等が挙げられる
。The insulating layer constituting the closed space together with the solid electrolyte membrane may be made of heat-resistant steel, aluminum oxide, platinum, or the like.
第１の固体電解質膜に特定物質を継続的に電解移動させ
る手段としては一通常該膜の両面に白金や銀からなる多
孔性電極（通常厚み、０．５〜２．０ｍ舅程度）を設は
両電極に電流を供給する回路が逝当であり、公知の種々
の回路が適用できる。なお、電解方向を適宜切替えるス
イッチを付設してもよい
（以下余白次頁に続く）
＠２の固体電解質膜の制御手段としては、まず。As a means for continuously electrolytically transferring a specific substance to the first solid electrolyte membrane, porous electrodes (usually about 0.5 to 2.0 m thick) made of platinum or silver are usually installed on both sides of the membrane. A circuit that supplies current to both electrodes is suitable, and various known circuits can be applied. Note that a switch may be provided to change the direction of electrolysis as appropriate (see below for margin). First, as a control means for the solid electrolyte membrane in @2.
第１図の回路に示す如き自動制御回路が挙げられる。制
御回路においてはＩＲドロップを補償する必要がある。An example is an automatic control circuit as shown in the circuit of FIG. It is necessary to compensate for IR drop in the control circuit.
ＩＲドロップ補償機能を備えた制御回路の他の具体例を
第４図に示す。第４図に示す制御回路は、＠１図にて示
したと同様に濃度センサーの本体における！！２の固体
電解質膜内外面（両端）の多孔性電極にそれぞれ（Ｗ）
、 （Ｇ）点を介して接続されてｈる。そして可変抵
抗Ｒ１α→、抵抗Ｒ１＠、抵抗Ｒ３（至）及び第２の固
体電解質膜自体の内部抵抗Ｒによって４辺ブリッジが形
成されるよう構成されてｈる。なお、抵抗Ｒ８（至）は
内部抵抗Ｒとほぼ等価に設定されている。また、Ｑｌは
固体電解質膜の両端電圧増幅器ｓＱ２は抵抗Ｒ８の両端
電圧増幅器％Ｑ、ＨＱ１及びＱ２の各出力電圧差に比例
した電圧を出力する増幅器、Ｑ４は第１図で示した制御
回路の補助加電圧電源（８）ＶＣ相当する電圧を設定す
る作動増＃Ｓ器、Ｑ、ｔ−ｊ位相反転回路ｉｐそれぞれ
示し、２つのトランジスターからなる回路（至）は回路
作動用の電流源を示しＱ、からのトランジスター出力に
よって制御される。Another specific example of a control circuit equipped with an IR drop compensation function is shown in FIG. The control circuit shown in Fig. 4 is in the main body of the concentration sensor, similar to that shown in Fig. 1! ! (W) on the porous electrodes on the inner and outer surfaces (both ends) of the solid electrolyte membrane in No. 2, respectively.
, (G) connected via the point h. A four-sided bridge is formed by the variable resistor R1α→, the resistor R1@, the resistor R3 (to), and the internal resistance R of the second solid electrolyte membrane itself. Note that the resistance R8 (to) is set to be approximately equivalent to the internal resistance R. Ql is a voltage amplifier across the solid electrolyte membrane, sQ2 is a voltage amplifier across the resistor R8, %Q, an amplifier that outputs a voltage proportional to the output voltage difference between HQ1 and Q2, and Q4 is the control circuit shown in FIG. Auxiliary voltage supply power supply (8) shows an operation intensifier S, Q, and tj phase inversion circuits ip that set a voltage equivalent to VC, and a circuit (to) consisting of two transistors shows a current source for circuit operation. Q, controlled by the transistor output from Q.
上記のごときＩＲドロップと電圧分とを分離して制御す
るように構成された制御回路を用いることによってＩｆ
ＲドロップをＩｆＲ，ドロップによって補償しなからＩ
ｆ を流して電解を行なうことができ、同時にＩｆを測
定することができる。By using a control circuit configured to separately control the IR drop and the voltage component as described above, If
If the R drop is compensated by the IfR drop, then I
Electrolysis can be performed by flowing f, and If can be measured at the same time.
なお、内部抵抗Ｒは温１ｉｔ一定ならば固有な値を示し
、従って可変抵抗Ｒ１の調整によって除去できる。この
ようなＩＲドロップ補償回路を備えた制御回路を適用す
ることにより高精度、高正確度の測定を行なうことがで
きる。なお、第２の固体電解質膜のＩＲ）’ロッゾを補
償する方法として上記以外に比較的周波数の高い交流を
重畳し、交流成分のみでＩＲ）’ロッゾを補償すること
も可能である。また、ｇｒ、５図に示すように、第２の
固体電解質膜（２）を絶縁体０７１で分離して固体電解
質膜（２′）及びｄ′）とし、ｅ″）で膜内・外面の電
位差を検出し！
これに対する負帰還電流を（２）の膜に通じて電解させ
る制御回路を構成することによりＩＲドロップの電位差
に対する影響を除去してもよい。Note that the internal resistance R exhibits a specific value if the temperature is constant, and can therefore be removed by adjusting the variable resistance R1. By applying a control circuit equipped with such an IR drop compensation circuit, highly precise and accurate measurements can be performed. In addition, as a method of compensating for the IR)'Rozzo of the second solid electrolyte membrane, it is also possible to superimpose an alternating current with a relatively high frequency in addition to the above, and compensate for the IR)'Rozzo using only the AC component. In addition, as shown in Figure 5, the second solid electrolyte membrane (2) is separated by an insulator 071 to form solid electrolyte membranes (2') and d'), and the inner and outer surfaces of the membrane are separated by e''). The influence of the IR drop on the potential difference may be removed by configuring a control circuit that detects the potential difference and electrolyzes the negative feedback current through the membrane (2).
なお、第２の固体電解質膜の内外両面に接触する特定物
質の濃度差に対応する電位差を検出するに当って、以上
に述べた装置ｒｃおいで＃′ｉ、両面に設けた多孔性電
極を通して両表面の電位差を直接検出して−るが、対象
とする特定物質によってはこれ以外の検出方法が可能で
ある。その具体例を＠６図に示す。図においては１ｇ２
の固体電解質（２）の内表面付近の特定物質の吸光度を
測定する、光源α転入射光透過面（ト）、分光フィルタ
ー翰及び受光器ａ１Ｄからなる吸光度測定部が付設され
ている。In addition, in detecting the potential difference corresponding to the concentration difference of a specific substance that is in contact with both the inner and outer surfaces of the second solid electrolyte membrane, the above-mentioned device rc is used to Although the surface potential difference is directly detected, other detection methods are possible depending on the specific substance of interest. A specific example is shown in Figure @6. In the figure, 1g2
An absorbance measuring section consisting of a light source α incoming light transmitting surface (g), a spectral filter window, and a light receiver a1D is attached to measure the absorbance of a specific substance near the inner surface of the solid electrolyte (2).
そして該吸光度を測定し、これを対応する電位に変換し
内外表面の電位差に対応する外表面との電位差を検出し
てこれに対する負帰還電流を流すことにより前記と同様
に濃度を測定することが可能である。ことに、塩素のご
とき紫外域に吸収を有する特定物質のように、特定波長
の電磁波に吸収を有する物質を対象とする場合、上記装
置を適用することができる。なお、この装置においては
第２の固体電解質膜でＤＩＲドロップを除外することが
できる利点を有してｂる。Then, the concentration can be measured in the same manner as above by measuring the absorbance, converting it into a corresponding potential, detecting the potential difference with the outer surface that corresponds to the potential difference between the inner and outer surfaces, and flowing a negative feedback current in response to this. It is possible. In particular, the above device can be applied to substances that absorb electromagnetic waves at specific wavelengths, such as specific substances such as chlorine that absorb in the ultraviolet region. Note that this device has the advantage of being able to eliminate DIR drops with the second solid electrolyte membrane.
この発明の濃度センサーは以上述べたように標章ガスを
全く必要とせず、連続測定に適している。As described above, the concentration sensor of the present invention does not require any marking gas and is suitable for continuous measurement.
さらに、前述した種々の利点を兼ね備えており、広い測
定範囲での高精度、高正確度の副定か可能である。そし
て、その構造上小型化が可能であり、微小センサー（例
えば直径１５φ酊、厚さ１餌程度）として使用すること
も容易に可能である。Furthermore, it has the various advantages mentioned above, and can perform sub-determination with high precision and accuracy over a wide measurement range. Due to its structure, it can be miniaturized, and it can easily be used as a minute sensor (for example, diameter 15φ, thickness about 1 piece).
第１図は、この発明の濃度センサーの一具体例を示す断
面図を含む機能説明図である。第２図は、ｗＪ１図で示
した！３度センサーの密閉空間内の濃度分布の例を示す
グラフである。第３図は、濃度センサ一本体の他側を示
す＠１図相当図である。第４図は、制御回路の他の具体
例を示す構成図である。第５図及び第６図は、それぞれ
この発明の濃度センサーの更に他の具体例を示−を第１
図相当図である。
（１）・・・＠１の固ｔＩ１．電解質膜、（２）・・・
１ｇ２の固体電解質膜、
（３）・・・絶縁層、（４）・・・多孔性電極、（５］
・・・密閉空間、（６）・・・電解用直流電源、（７）
・・・負帰還増幅器、（８）・・・補助加電圧電源、（
９）・・・電極電位差測定器、αＱ・・・ＩＲドロップ
検出器。
αＢ・・・負帰還回警抵抗、（６）、α◆・・・可変抵
抗（至）・・・電流源、 （ト）、αＱ・・・抵
抗、Ｑｆ）・・・絶縁体、 （至）・・・入射光
透過面、α呻・・・光源、 翰・・・分光フィ
ルター、（２）・・・受光器、 翰・・・電流計
、Ｐ・・・電解移動手段及び制御手段、
Ｑｌ、Ｑ２・・・両端電圧増幅器。
Ｑ８・・・電圧差増幅器ｓ Ｑ４・・・作動増幅器。
Ｑ、・・・位相反転回路。
代理人 弁理士 野河信太゛９部巳
・−＝＋［：、ｉ’FIG. 1 is a functional explanatory diagram including a sectional view showing a specific example of the concentration sensor of the present invention. Figure 2 is shown in wJ1 diagram! It is a graph showing an example of concentration distribution in a closed space of a 3-degree sensor. FIG. 3 is a view corresponding to FIG. 1 showing the other side of the concentration sensor main body. FIG. 4 is a configuration diagram showing another specific example of the control circuit. 5 and 6 respectively show still other specific examples of the concentration sensor of the present invention.
It is a figure equivalent figure. (1)...@1's fixed tI1. Electrolyte membrane, (2)...
1g2 solid electrolyte membrane, (3)...insulating layer, (4)...porous electrode, (5)
... Closed space, (6) ... DC power supply for electrolysis, (7)
... Negative feedback amplifier, (8) ... Auxiliary voltage supply power supply, (
9)...Electrode potential difference measuring device, αQ...IR drop detector. αB...Negative feedback loop resistance, (6), α◆...Variable resistance (To)...Current source, (G), αQ...Resistance, Qf)...Insulator, (To )... Incident light transmitting surface, α... light source, wire... spectral filter, (2)... light receiver, wire... ammeter, P... electrolysis moving means and control means, Ql, Q2...Both ends voltage amplifier. Q8... Voltage difference amplifier s Q4... Working amplifier. Q...Phase inversion circuit. Agent: Patent attorney Shinta Nogawa 9th grade -=+[:,i'
Claims (1)
り密閉された特定物質の流動可能な空間を形成する本体
、第１の固体電解質膜に設けられた特定物質を該電解質
膜を通して継続的に電解移動させる手段、第２の固体電
解質膜に設けられた該固体電解質膜の内外両面に接触す
る特定物質の濃度差に対応する電位差を検出し該電位差
が一定の設定値となるように負帰還電流を流して特定物
質を電解移動させる制御手段、及び上記負帰還電流の測
定手段を備え、負帰還電流に基づいて密閉された空間外
の特定物質の濃度を測定できるよう構成してなる特定物
質の濃度センサー。1. A main body that forms a space in which a specific substance can flow, which is sealed by opposing first and second solid electrolyte membranes and an insulating layer, and the specific substance provided in the first solid electrolyte membrane is continued through the electrolyte membrane. means for electrolytically moving the second solid electrolyte membrane, detecting a potential difference corresponding to a concentration difference of a specific substance in contact with both the inner and outer surfaces of the solid electrolyte membrane, and adjusting the potential difference to a constant set value; It is equipped with a control means for electrolytically moving a specific substance by flowing a negative feedback current, and a measuring means for the negative feedback current, and configured to be able to measure the concentration of the specific substance outside the sealed space based on the negative feedback current. Concentration sensor for specific substances.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56131100A JPS5832156A (en) | 1981-08-20 | 1981-08-20 | Sensor for concentration of specific substance |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56131100A JPS5832156A (en) | 1981-08-20 | 1981-08-20 | Sensor for concentration of specific substance |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5832156A true JPS5832156A (en) | 1983-02-25 |
| JPS64659B2 JPS64659B2 (en) | 1989-01-09 |
Family
ID=15049972
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP56131100A Granted JPS5832156A (en) | 1981-08-20 | 1981-08-20 | Sensor for concentration of specific substance |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5832156A (en) |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS59108951A (en) * | 1982-12-15 | 1984-06-23 | Hitachi Ltd | Oxygen pump type air/fuel ratio sensor |
| EP0126590A2 (en) * | 1983-05-11 | 1984-11-28 | Mitsubishi Denki Kabushiki Kaisha | Air-to-fuel ratio sensor for engine |
| EP0127964A2 (en) * | 1983-05-11 | 1984-12-12 | Mitsubishi Denki Kabushiki Kaisha | Air-to-fuel ratio sensor for engine |
| JPS59224554A (en) * | 1983-06-03 | 1984-12-17 | Mitsubishi Electric Corp | Element for gaseous oxygen concentration cell |
| EP0138170A2 (en) * | 1983-10-14 | 1985-04-24 | Mitsubishi Denki Kabushiki Kaisha | Air-to-fuel ratio detector for engines |
| EP0148622A2 (en) * | 1983-12-24 | 1985-07-17 | Ngk Insulators, Ltd. | Process of manufacturing electrochemical device |
| EP0152293A2 (en) * | 1984-02-08 | 1985-08-21 | Mitsubishi Denki Kabushiki Kaisha | Engine air/fuel ratio sensing device |
| JPS6188138A (en) * | 1985-09-21 | 1986-05-06 | Ngk Insulators Ltd | Electrochemical device |
| WO1993021521A1 (en) * | 1992-04-13 | 1993-10-28 | Hitachi, Ltd. | Air-fuel ratio sensor for internal combustion |
| JP2015534081A (en) * | 2012-11-12 | 2015-11-26 | ローベルト ボツシユ ゲゼルシヤフト ミツト ベシユレンクテル ハフツングＲｏｂｅｒｔ Ｂｏｓｃｈ Ｇｍｂｈ | Method for operating a solid electrolyte sensor element including a pump cell |
-
1981
- 1981-08-20 JP JP56131100A patent/JPS5832156A/en active Granted
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS59108951A (en) * | 1982-12-15 | 1984-06-23 | Hitachi Ltd | Oxygen pump type air/fuel ratio sensor |
| EP0126590A2 (en) * | 1983-05-11 | 1984-11-28 | Mitsubishi Denki Kabushiki Kaisha | Air-to-fuel ratio sensor for engine |
| EP0127964A2 (en) * | 1983-05-11 | 1984-12-12 | Mitsubishi Denki Kabushiki Kaisha | Air-to-fuel ratio sensor for engine |
| JPS59224554A (en) * | 1983-06-03 | 1984-12-17 | Mitsubishi Electric Corp | Element for gaseous oxygen concentration cell |
| EP0138170A2 (en) * | 1983-10-14 | 1985-04-24 | Mitsubishi Denki Kabushiki Kaisha | Air-to-fuel ratio detector for engines |
| EP0148622A2 (en) * | 1983-12-24 | 1985-07-17 | Ngk Insulators, Ltd. | Process of manufacturing electrochemical device |
| US4610741A (en) * | 1983-12-24 | 1986-09-09 | Ngk Insulators, Ltd. | Process of manufacturing electrochemical device |
| EP0152293A2 (en) * | 1984-02-08 | 1985-08-21 | Mitsubishi Denki Kabushiki Kaisha | Engine air/fuel ratio sensing device |
| JPS6188138A (en) * | 1985-09-21 | 1986-05-06 | Ngk Insulators Ltd | Electrochemical device |
| WO1993021521A1 (en) * | 1992-04-13 | 1993-10-28 | Hitachi, Ltd. | Air-fuel ratio sensor for internal combustion |
| JP2015534081A (en) * | 2012-11-12 | 2015-11-26 | ローベルト ボツシユ ゲゼルシヤフト ミツト ベシユレンクテル ハフツングＲｏｂｅｒｔ Ｂｏｓｃｈ Ｇｍｂｈ | Method for operating a solid electrolyte sensor element including a pump cell |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS64659B2 (en) | 1989-01-09 |
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