JPH0634700Y2 - Conductivity meter measurement circuit - Google Patents
Conductivity meter measurement circuitInfo
- Publication number
- JPH0634700Y2 JPH0634700Y2 JP8996887U JP8996887U JPH0634700Y2 JP H0634700 Y2 JPH0634700 Y2 JP H0634700Y2 JP 8996887 U JP8996887 U JP 8996887U JP 8996887 U JP8996887 U JP 8996887U JP H0634700 Y2 JPH0634700 Y2 JP H0634700Y2
- Authority
- JP
- Japan
- Prior art keywords
- electrode
- electrodes
- conductivity meter
- reference potential
- input terminal
- 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
Landscapes
- Measurement Of Resistance Or Impedance (AREA)
- Investigating Or Analyzing Materials By The Use Of Electric Means (AREA)
Description
【考案の詳細な説明】 〈産業上の利用分野〉 本考案は３極方式の導電率計において、電極部は従来装
置と同一形状のまま、セル定数を大きくすることが出来
る導電率計測定回路に関する。DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention is a three-pole type conductivity meter, in which the electrode constant is the same as that of the conventional device, and the cell constant can be increased to increase the cell constant. Regarding
〈従来の技術〉 導電率計では測定精度を挙げる為に第２図に示すような
３極方式の測定セルが用いられている。図中、E1，E2，
E3は夫々被測定液に浸漬される電極で、これら電極は絶
縁体1a,1bによって所定間隔l1，l2離して配置されてい
る。２は正、負対称の交流印加電圧を発生する発振回路
で、ここからの印加電圧V1はボルテージフォロワA1を経
て電極E1，E2に印加される。<Prior Art> A conductivity meter uses a three-pole measurement cell as shown in FIG. 2 in order to improve the measurement accuracy. In the figure, E 1 , E 2 ,
E 3 is an electrode immersed in the liquid to be measured, and these electrodes are arranged at a predetermined distance l 1 and l 2 by insulators 1a and 1b. Reference numeral 2 is an oscillating circuit that generates positive and negative symmetrical AC applied voltages, and the applied voltage V 1 from here is applied to the electrodes E 1 and E 2 via a voltage follower A 1 .
電極E1とE2とは互いに接続され、同電位に保たれるた
め、これら電極間には電流が流れず指示誤差は発生しな
い。即ち、電極E1とE2とが接続されていない場合、測定
セル外に点線で示す電流が流れ、測定セル外の状態によ
ってこれが変化し指示誤差を発生するが、このような誤
差が防げる。Since the electrodes E 1 and E 2 are connected to each other and kept at the same potential, a current does not flow between these electrodes and an indication error does not occur. That is, when the electrodes E 1 and E 2 are not connected, a current indicated by a dotted line flows outside the measurement cell and changes depending on the state outside the measurement cell to generate an indication error, but such an error can be prevented.
A2は非反転入力端子が基準電位に接続され、反転入力端
子が電極E3に接続され、帰還回路にレンジ抵抗Rfが接続
された演算増幅器で、この演算増幅器には、電極E1，E3
間に流れる電流i1と電極E2，E3間に流れる電流i2との和
の電流が流れ、この電流に対応した出力電圧Voを発生す
る。A 2 is a non-inverting input terminal connected to a reference potential, an inverting input terminal connected to the electrode E 3, in the range resistor R f in the feedback circuit is connected an operational amplifier, to the operational amplifier, the electrodes E 1, E 3
The sum of the current i 1 flowing between the electrodes and the current i 2 flowing between the electrodes E 2 and E 3 flows, and an output voltage V o corresponding to this current is generated.
このような構成の測定セルの場合、セル定数Kaは以下の
ように表わすことが出来る。For measuring cell of such a structure, cell constant K a may be represented as follows.
Ka＝（K1・K2）／（K1＋K2） …（１） 但し、K1＝α・（l1/S）， K2＝α・（l2/S）。K a = (K 1 · K 2 ) / (K 1 + K 2 ) ... (1) where K 1 = α · (l 1 / S) and K 2 = α · (l 2 / S).
（α：電極の形状により決まる定数、S:電極断面積） 今、l1＋l2＝ｌとすると、（１）式は以下（２）式のよ
うに書き改めることができ、 Ka＝｛α／（Ｓ・ｌ）｝・｛−l1 2＋（ｌ・l1）｝ …
（２） この式において最大のセル定数Kaを与えるl1は、l1＝
（1/2）・ｌのとき、即ち、l1＝l2のときである。(Α: constant determined by the shape of the electrode, S: electrode cross-sectional area) Now, if l 1 + l 2 = l, then equation (1) can be rewritten as equation (2) below, and K a = { α / (S · l)} · {−l 1 2 + (l·l 1 )} ...
(2) l 1 to provide maximum cell constant K a in this formula, l 1 =
When (1/2) · l, that is, when l 1 = l 2 .
〈考案が解決しようとする問題点〉 従来装置において、最大セル定数Kaは、 Ka＝（1/2）・α・（l1/S）＝（1/4）・α・（l/S） …
（３） で表わされ、セル形状（S,l）が一定なら、この値はこ
れ以上大きくなり得ない。<Problems to be solved by the invention> In the conventional device, the maximum cell constant K a is K a = (1/2) · α · (l 1 / S) = (1/4) · α · (l / S) ...
If the cell shape (S, l) is represented by (3), this value cannot be larger than this.
このため、従来装置では導電率の大きな被測定液を測定
する場合、セル定数を大きくするためにｌの大きい大型
の測定セルを使っていた。For this reason, in the conventional apparatus, when measuring a liquid to be measured having a large conductivity, a large measuring cell having a large l was used in order to increase the cell constant.
本考案の解決しようとする技術的課題は、電極の外径寸
法は従来装置のままで、セル定数を従来装置より大きく
することにある。The technical problem to be solved by the present invention is to increase the cell constant as compared with the conventional device while keeping the outer diameter of the electrode as it is in the conventional device.
〈問題点を解決するための手段〉 本考案の構成は、交流電圧源と、夫々被測定液に浸漬さ
れ、前記交流電圧源から交流電圧が印加された第１の電
極、基準電位に接続された第２の電極、及び前記第１の
電極に対向配置された第３の電極を含む電極部と、一方
の入力端子が前記基準電位に接続され、他の入力端子が
前記第３の電極に接続され、帰還回路にレンジ抵抗が接
続され、前記第１、第３の電極間に流れる電流に対応し
た出力電圧を発生する演算増幅器とを具備し、前記第１
の電極を前記第２の電極側に近接配置し、前記第１の電
極と第３の電極との間隔を大としたことにある。<Means for Solving Problems> The configuration of the present invention is such that an AC voltage source, a first electrode immersed in a solution to be measured, respectively, to which an AC voltage is applied from the AC voltage source, and a reference potential are connected. An electrode portion including a second electrode and a third electrode arranged to face the first electrode, one input terminal is connected to the reference potential, and the other input terminal is connected to the third electrode. An operational amplifier that is connected to the feedback circuit, connects a range resistor to the feedback circuit, and generates an output voltage corresponding to a current flowing between the first and third electrodes.
That is, the above electrode is arranged close to the second electrode side, and the distance between the first electrode and the third electrode is increased.
〈作用〉 前記の技術手段は次のように作用する。即ち、前記第２
の電極は基準電位に接続され、また、前記第３の電極も
前記演算増幅器の帰還作用により基準電位に保たれるた
め、測定セル外のループを通って前記第１、第３の電極
間に流れる電流は生ぜず、指示誤差は発生しない。<Operation> The above technical means operates as follows. That is, the second
Is connected to a reference potential, and the third electrode is also kept at the reference potential by the feedback action of the operational amplifier. Therefore, the third electrode is passed between the first and third electrodes through a loop outside the measurement cell. No flowing current is generated and no indication error occurs.
また、導電率の測定は第１、第３の電極間に流れる電流
に基づいて測定され、セル定数は第１、第３の電極間の
間隔、電極断面積に依存し、前記第１、第２の電極間の
間隔、電極断面積とは無関係となる為、前記第１、第３
の電極間の間隔を可能な限り大きくとることが出来、従
来装置と同一形状で大きなセル定数が実現出来る。The conductivity is measured based on the current flowing between the first and third electrodes, and the cell constant depends on the distance between the first and third electrodes and the electrode cross-sectional area. Since it has nothing to do with the distance between the two electrodes and the electrode cross-sectional area,
The distance between the electrodes can be made as large as possible, and a large cell constant can be realized with the same shape as the conventional device.
〈実施例〉 以下図面に従い本考案の実施例を説明する。第１図は本
考案実施例装置の回路図である。図中、第２図における
要素と同じ要素には同一符号を付し、これらについての
説明は省略する。<Embodiment> An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a circuit diagram of the device of the present invention. In the figure, the same elements as the elements in FIG. 2 are designated by the same reference numerals, and the description thereof will be omitted.
E4はボルテージフォロワA1より印加電圧V1が加えられた
電極、E5は基準電位に接続された電極、E6は電極E4に対
向配置された電極で、この電極E6は演算増幅器A2反転入
力端子に接続されている。E 4 is an electrode to which an applied voltage V 1 is applied from the voltage follower A 1 , E 5 is an electrode connected to the reference potential, E 6 is an electrode arranged opposite to the electrode E 4 , and this electrode E 6 is an operational amplifier. A 2 Connected to inverting input terminal.
このような構成で、電極E5は基準電位に接続され、電極
E6は演算増幅器A2の帰還作用により基準電位に保たれる
ため、測定セル以外のループを通ってこれら電極間に流
れる電流は生ぜずこれに基づく指示誤差は発生しない。With such a configuration, the electrode E 5 is connected to the reference potential and the electrode
Since E 6 is kept at the reference potential by the feedback action of the operational amplifier A 2, a current that flows between these electrodes through a loop other than the measurement cell does not occur and an instruction error based on this does not occur.
更に、電極E4，E6間は常にV1に保たれる為、導電率は電
極E4，E6間に流れる電流i2に基づいて測定することがで
き、電極E4，E5間の電流i1は測定に関与しない。従っ
て、セル定数は電極E4とE6との距離及び電極断面積によ
ってのみ定まる。Further, since the voltage between the electrodes E 4 and E 6 is always kept at V 1 , the conductivity can be measured based on the current i 2 flowing between the electrodes E 4 and E 6 , and the conductivity between the electrodes E 4 and E 5 can be measured. Current i 1 of does not participate in the measurement. Therefore, the cell constant is determined only by the distance between the electrodes E 4 and E 6 and the electrode cross-sectional area.
今、電極E4，E5間の間隔をl1′、電極E4，E6間の間隔を
l2′とし、 l1′＋l2′＝ｌとすると、セル定数Kbは、 Kb＝α・（l2′/S） …（４） で表わされる。l2′はl1′と独立して定められるから、
l1′より充分大きくすることができる。今、l1′＝0.1l
2′とすると、 l2′＝（10/11）・ｌ …（５） となり、この場合のセル定数Kbは、 Kb＝（10/11）・α・（l/S） …（６） となり、同一形状のままでも、従来装置と比べて約４倍
も大きなセル定数が実現できる。Now, the distance between electrodes E 4 and E 5 is l 1 ′, and the distance between electrodes E 4 and E 6 is
Assuming that l 2 ′ and l 1 ′ + l 2 ′ = 1, the cell constant K b is expressed by K b = α · (l 2 ′ / S) (4). Since l 2 ′ is defined independently of l 1 ′,
It can be much larger than l 1 ′. Now l 1 ′ ＝ 0.1l
If 2 ′, then l 2 ′ = (10/11) · l (5), and the cell constant K b in this case is K b = (10/11) · α · (l / S)… (6 ), Even with the same shape, it is possible to realize a cell constant about four times larger than that of the conventional device.
〈考案の効果〉 本考案によれば、電極部を３極方式とし、測定セル外を
流れる電流を無くし、これによる指示誤差を防いだ導電
率計において、電極の大きさを従来装置と同一のままと
し、セル定数を従来のものより大きくすることができ
る。このため、導電率の大きな被測定液を測定する場合
でも電極部分を大型にする必要がなく、僅かな量のサン
プルで導電率の測定が行える。<Effect of the Invention> According to the present invention, in the conductivity meter in which the electrode portion is a three-pole type, the current flowing outside the measuring cell is eliminated, and the indication error due to this is prevented, the electrode size is the same as that of the conventional device. The cell constant can be increased and the cell constant can be made larger than the conventional one. Therefore, even when measuring a liquid to be measured having a large conductivity, it is not necessary to make the electrode portion large, and the conductivity can be measured with a small amount of sample.
尚、上記本考案の実施例では、電極E4にボルテージフォ
ロワA1より印加電圧V1を加え、電極E6を演算増幅器A2の
反転入力端子に接続した構成になっているが電極E4を演
算増幅器A2の反転入力端子に接続し、電極E6にボルテー
ジフォロワA1から印加電圧V1を加えるような構成にして
も全く同様な効果が得られる。In the embodiment of the present invention, the applied voltages V 1 from the voltage follower A 1 applied to the electrodes E 4, but has a configuration which is connected to the inverting input terminal electrodes of the electrode E 6 operational amplifier A 2 E 4 Is connected to the inverting input terminal of the operational amplifier A 2 , and the voltage E 1 is applied to the electrode E 6 from the voltage follower A 1 to obtain the same effect.
第１図は本考案実施例装置の回路図、第２図は従来装置
の回路図である。 ２……発振回路、E4……第１の電極、E5……第２の電
極、E6……第３の電極、A1……ボルテージフォロワ、A2
……演算増幅器FIG. 1 is a circuit diagram of a device of the present invention, and FIG. 2 is a circuit diagram of a conventional device. 2 ... Oscillation circuit, E 4 ...... First electrode, E 5 ...... Second electrode, E 6 ...... Third electrode, A 1 ...... Voltage follower, A 2
...... Operational amplifier
Claims (1)
前記交流電圧源から交流電圧が印加された第１の電極、
基準電位に接続された第２の電極、及び前記第１の電極
に対向配置された第３の電極を含む電極部と、一方の入
力端子が前記基準電位に接続され、他の入力端子が前記
第３の電極に接続され、帰還回路にレンジ抵抗が接続さ
れ、前記第１、第３の電極間に流れる電流に対応した出
力電圧を発生する演算増幅器とを具備し、前記第１の電
極を前記第２の電極側に近接配置し、前記第１、第３の
電極の間隔を大としたことを特徴とする導電率計測定回
路。1. An alternating voltage source and a liquid to be measured, respectively,
A first electrode to which an alternating voltage is applied from the alternating voltage source,
An electrode portion including a second electrode connected to a reference potential and a third electrode arranged to face the first electrode, one input terminal is connected to the reference potential, and the other input terminal is An operational amplifier connected to a third electrode, connected to a range resistor to the feedback circuit, and generating an output voltage corresponding to a current flowing between the first and third electrodes, A conductivity meter measuring circuit, wherein the conductivity meter measuring circuit is arranged close to the second electrode side, and the distance between the first and third electrodes is large.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8996887U JPH0634700Y2 (en) | 1987-06-11 | 1987-06-11 | Conductivity meter measurement circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8996887U JPH0634700Y2 (en) | 1987-06-11 | 1987-06-11 | Conductivity meter measurement circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS63199075U JPS63199075U (en) | 1988-12-21 |
| JPH0634700Y2 true JPH0634700Y2 (en) | 1994-09-07 |
Family
ID=30949428
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP8996887U Expired - Lifetime JPH0634700Y2 (en) | 1987-06-11 | 1987-06-11 | Conductivity meter measurement circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0634700Y2 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2001063269A1 (en) * | 2000-02-22 | 2001-08-30 | Organo Corporation | Apparatus for measuring conductivity |
| WO2001063268A1 (en) * | 2000-02-23 | 2001-08-30 | Organo Corporation | Multiple electric conductivity measuring apparatus |
| WO2001075428A1 (en) * | 2000-03-30 | 2001-10-11 | Organo Corporation | Ion concentration meter |
| JP2008134264A (en) * | 2008-02-25 | 2008-06-12 | Hioki Ee Corp | Impedance measuring device |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001311710A (en) * | 2000-02-23 | 2001-11-09 | Japan Organo Co Ltd | Multiple conductivity measuring device |
-
1987
- 1987-06-11 JP JP8996887U patent/JPH0634700Y2/en not_active Expired - Lifetime
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2001063269A1 (en) * | 2000-02-22 | 2001-08-30 | Organo Corporation | Apparatus for measuring conductivity |
| WO2001063268A1 (en) * | 2000-02-23 | 2001-08-30 | Organo Corporation | Multiple electric conductivity measuring apparatus |
| WO2001075428A1 (en) * | 2000-03-30 | 2001-10-11 | Organo Corporation | Ion concentration meter |
| JP2008134264A (en) * | 2008-02-25 | 2008-06-12 | Hioki Ee Corp | Impedance measuring device |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS63199075U (en) | 1988-12-21 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| GB1463880A (en) | Apparatus for conductivity measurements | |
| JPH06501316A (en) | Integrable conductivity measuring device | |
| JPH0634700Y2 (en) | Conductivity meter measurement circuit | |
| US3635681A (en) | Differential conductivity-measuring apparatus | |
| JPS61280560A (en) | Method for measuring concentration of oxygen | |
| JPH0621016Y2 (en) | Conductivity meter | |
| JPS632469B2 (en) | ||
| JPH076536Y2 (en) | Conductivity meter | |
| JPS6313486Y2 (en) | ||
| JP2801304B2 (en) | Solution resistivity measuring device | |
| SU1597776A1 (en) | Digital meter of specific conductance of liquids | |
| JPH0450502Y2 (en) | ||
| JP3372173B2 (en) | Capacitance type level measuring device | |
| JPH0526977Y2 (en) | ||
| JPS5833562Y2 (en) | Sodium hypochlorite measuring device | |
| JP2505817Y2 (en) | Electromagnetic flow meter | |
| JPH052864Y2 (en) | ||
| JPS61102876U (en) | ||
| JPS5914758Y2 (en) | Cell for liquid conductivity meter | |
| JPS5830231Y2 (en) | Pure water conductivity measuring device | |
| JPS6023993Y2 (en) | Hall element residual voltage adjustment circuit | |
| SU114776A1 (en) | Paul Rograf | |
| JPH0620117Y2 (en) | Temperature detection circuit | |
| SU394735A1 (en) | DEVICE FOR RESEARCH OF ELECTROPHYSICAL PARAMETERS OF MATERIALS | |
| SU1346999A1 (en) | Method of checking degree of liquid inhomogeneity |