JPH07239313A - Electric conductivity measuring method - Google Patents

Electric conductivity measuring method

Info

Publication number
JPH07239313A
JPH07239313A JP2967594A JP2967594A JPH07239313A JP H07239313 A JPH07239313 A JP H07239313A JP 2967594 A JP2967594 A JP 2967594A JP 2967594 A JP2967594 A JP 2967594A JP H07239313 A JPH07239313 A JP H07239313A
Authority
JP
Japan
Prior art keywords
potential
measuring
resistance
conductivity
medium
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.)
Granted
Application number
JP2967594A
Other languages
Japanese (ja)
Other versions
JP3166471B2 (en
Inventor
Toshibumi Fukui
俊文 福井
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Shimadzu Corp
Original Assignee
Shimadzu Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Shimadzu Corp filed Critical Shimadzu Corp
Priority to JP02967594A priority Critical patent/JP3166471B2/en
Publication of JPH07239313A publication Critical patent/JPH07239313A/en
Application granted granted Critical
Publication of JP3166471B2 publication Critical patent/JP3166471B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

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Abstract

PURPOSE:To calculate the electric conductivity of a medium liquid by a simple operation at the time of the measurement of potential such as drift potential. CONSTITUTION:After potential is measured by a potential measuring electrode 63, a resistor 66 of which resistance value is known is connected to the electrode 63 to measure potential and, thereafter, a resistance measuring electrode 64 is connected to the electrode 63 in place of the resistor 66 to measure potential. The electric conductivity of a medium liquid 8 is calculated using those measured values.

Description

【発明の詳細な説明】Detailed Description of the Invention

【0001】[0001]

【産業上の利用分野】本発明は、例えば流動電位法によ
りゼータ電位を求める場合に必要な媒液の導電率を測定
する方法に関する。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring the electrical conductivity of a liquid medium, which is necessary when the zeta potential is obtained by the streaming potential method.

【0002】[0002]

【従来の技術】試料と媒液との界面の荷電状態を示すゼ
ータ電位は、沈降電位や流動電位等の界面動電現象の測
定から計算式を用いて間接的に求められるが、この場合
のゼータ電位の算出には媒液の導電率を求める必要があ
る。例えば、流動電位法では、ゼータ電位ζと流動電位
Eとを関係づける下記の式(1)を用い、媒液の粘性係
数ηおよび誘電率εを一定とみなして、媒液を流動させ
るために加える圧力Pを変化させながら流動電位Eを測
定することによりゼータ電位ζを求めるが、その場合、
流動電位Eと圧力Pのほかに媒液の導電率λを知る必要
がある。
2. Description of the Related Art The zeta potential, which indicates the charge state at the interface between a sample and a liquid medium, is indirectly determined using a calculation formula from the measurement of electrokinetic phenomena such as sedimentation potential and streaming potential. In order to calculate the zeta potential, it is necessary to obtain the conductivity of the liquid medium. For example, in the streaming potential method, the following equation (1) that relates the zeta potential ζ and the streaming potential E is used, and the viscosity coefficient η and the dielectric constant ε of the medium liquid are regarded as constant, and the medium liquid is made to flow. The zeta potential ζ is obtained by measuring the streaming potential E while changing the applied pressure P. In that case,
In addition to the streaming potential E and the pressure P, it is necessary to know the conductivity λ of the liquid medium.

【0003】[0003]

【数1】 [Equation 1]

【0004】ところで、媒液中に粒子ないし固形の試料
が存在する系においては、試料への媒液分子ないしイオ
ンの吸着により電気二重層が形成されるため、媒液の導
電率は、そのような吸着状態に依存することとなる。し
たがって、媒液の導電率については、文献値等をそのま
ま用いることはできず、実際の状態での値を測定する必
要がある。このため、従来においては、電位測定後に媒
液を取り出し、その取り出した媒液内に導電率測定セル
を浸して導電率を測定するという操作が行われていた。
By the way, in a system in which particles or solid samples are present in the liquid medium, the electric double layer is formed by adsorption of the liquid medium molecules or ions to the sample, so that the conductivity of the liquid medium is It depends on the adsorption state. Therefore, for the conductivity of the liquid medium, it is not possible to directly use the literature value or the like, and it is necessary to measure the value in the actual state. Therefore, conventionally, an operation of taking out the medium solution after measuring the potential and immersing the conductivity measuring cell in the taken-out medium solution to measure the conductivity has been performed.

【0005】[0005]

【発明が解決しようとする課題】上述のような従来の方
法では、電位測定と導電率測定とを別々に行っているた
め、操作全体が煩雑で手間のかかるものとなっていた。
また、測定装置においても、電位測定用の電気回路とは
別に導電率測定用の電気回路を備える必要があるため、
それだけシステム全体が大掛かりなものとなっていた。
さらに、導電率の測定は、直接媒液の電気抵抗を測定す
ることにより行っていたため、導電率の低いものは測定
するのが難しいという一面もあった。
In the conventional method as described above, since the potential measurement and the conductivity measurement are performed separately, the entire operation is complicated and troublesome.
Further, even in the measuring device, since it is necessary to provide an electric circuit for measuring conductivity in addition to the electric circuit for measuring potential,
The whole system was so large.
Further, the conductivity is measured by directly measuring the electric resistance of the medium liquid, and therefore, it is difficult to measure the conductivity having a low conductivity.

【0006】これらの点に加え、従来においては、電位
測定後に媒液のみを取り出して外側の導電率測定セルで
媒液のみの導電率を別途測定していたため、試料への媒
液分子等の吸着状態が十分に加味されているとは言えな
い面があった。つまり、実際は荷電粒子間の相互作用
(表面伝導等)により電気が流れることがあるが、上述
のように電位測定用セルの外側で媒液の導電率を測定す
ると、そのような粒子間の相互作用のない下での値しか
求めることができず、実際の電位測定中の状態に見合っ
た導電率が得られないのである。
In addition to these points, in the prior art, only the medium solution was taken out after the potential measurement and the conductivity of only the medium solution was separately measured in the outer conductivity measuring cell. There was a side that could not be said that the adsorbed state was fully added. In other words, in reality, electricity may flow due to the interaction between charged particles (surface conduction, etc.), but if the conductivity of the liquid medium is measured outside the potential measuring cell as described above, the mutual interaction between such particles will occur. Only the value under no action can be obtained, and the electrical conductivity corresponding to the state during actual potential measurement cannot be obtained.

【0007】さらに、電位および導電率の測定は本来同
じ条件下で行う必要があるにもかかわらず、各測定を別
個に行う従来の方法の下では、稀なケースではあるが、
測定者の誤解や不慣れ等により或る程度時間や日が経過
してから異なる温度条件の下で別々に測定が行われると
いう問題も生じていた。
Furthermore, although it is necessary to measure potential and conductivity under the same conditions, although it is a rare case under the conventional method in which each measurement is performed separately,
There has also been a problem that the measurement is performed separately under different temperature conditions after a certain amount of time or day has passed due to the misunderstanding or unfamiliarity of the measurer.

【0008】なお、このような問題を回避するには電位
測定用セルの中で媒液の導電率を測定することとすれば
よいが、実際には導電率測定セルのセル定数が媒液分子
等の吸着状態によって変化し、これにセル定数を対応さ
せる必要があることから、電位測定用セルの中で導電率
の測定を行うのは困難であった。
In order to avoid such a problem, the conductivity of the medium solution may be measured in the potential measuring cell. In practice, however, the cell constant of the conductivity measuring cell is the medium molecule. It has been difficult to measure the electrical conductivity in the potential measuring cell because it changes depending on the adsorption state such as, and it is necessary to correspond the cell constant.

【0009】本発明は、上述のような問題に対処するも
ので、電位測定中の実際の状態に見合った導電率を簡単
な操作で求めることができ、しかも従来よりもシステム
構成を簡素化できる導電率の測定方法を提供することを
目的とする。
The present invention addresses the above-mentioned problems, and the conductivity suitable for the actual state during potential measurement can be obtained by a simple operation, and the system configuration can be simplified more than before. It is an object of the present invention to provide a method for measuring conductivity.

【0010】[0010]

【課題を解決するための手段】上記目的達成のため、本
発明の導電率測定方法は、電位測定時にその電位測定回
路に抵抗を付加すると電位測定値が変化する点を利用し
て、次のように構成したことを特徴とする。
In order to achieve the above object, the conductivity measuring method of the present invention utilizes the point that the potential measurement value changes when a resistance is added to the potential measurement circuit at the time of potential measurement. It is characterized in that it is configured as follows.

【0011】すなわち、媒液中に粒子または固形の試料
が存在する系において、その媒液の導電率を測定するに
あたり、試料と媒液との相対運動により生じる電位差を
一対の電位測定電極で測定する第1操作と、前記一対の
電位測定電極に抵抗値が既知の抵抗を並列または直列に
接続して両電極間の電位差を測定する第2操作と、前記
一対の電位測定電極に媒液の電気抵抗を測定するための
一対の抵抗測定電極を並列または直列に接続して前記一
対の電位測定電極間の電位差を測定する第3操作とを行
う。そして、第1および第2操作の測定結果から電位測
定電極の内部抵抗値を求めて、その内部抵抗値と第3操
作の測定結果とから媒液の電気抵抗を求め、さらにその
電気抵抗を用いて媒液の導電率を決定する。
That is, in a system in which a particle or solid sample is present in a medium, in measuring the conductivity of the medium, the potential difference caused by relative motion between the sample and the medium is measured with a pair of potential measuring electrodes. And a second operation for measuring a potential difference between both electrodes by connecting a resistor having a known resistance value in parallel or in series to the pair of potential measurement electrodes, and a liquid medium for the pair of potential measurement electrodes. A third operation of connecting a pair of resistance measuring electrodes for measuring electric resistance in parallel or in series and measuring a potential difference between the pair of potential measuring electrodes is performed. Then, the internal resistance value of the potential measuring electrode is determined from the measurement results of the first and second operations, the electrical resistance of the medium liquid is determined from the internal resistance value and the measurement result of the third operation, and the electrical resistance is used. Determines the conductivity of the liquid medium.

【0012】なお、前記第1〜第3操作は、いずれが先
でも後でもよく、その順番は問わない。
Any of the first to third operations may be performed first or later, and the order thereof is not limited.

【0013】[0013]

【作用】上記の構成によれば、第1操作を行った時に、
電位測定電極で検出される電位差、つまり試料と媒液と
の相対運動により生じる流動電位等を測定される。そし
て、第2操作時において、その電位測定電極に既知の抵
抗を接続した時、同電極間の電位差が変化するから、同
電極を電池と内部抵抗の組合せと考えてオームの法則を
適用すると、既知抵抗の接続前後の両電位差の値から計
算により電位測定電極の内部抵抗値が求まる。この場
合、試料の状態は既知抵抗の接続・非接続によって変わ
ることはないから、上記のようにして求められた内部抵
抗値は、電位測定中の試料の状態を正しく反映したもの
となる。
According to the above construction, when the first operation is performed,
The potential difference detected by the potential measuring electrode, that is, the streaming potential generated by the relative movement between the sample and the liquid medium is measured. Then, at the time of the second operation, when a known resistance is connected to the potential measuring electrode, the potential difference between the electrodes changes, so if Ohm's law is applied considering the electrode as a combination of the battery and the internal resistance, The internal resistance value of the potential measuring electrode is obtained by calculation from the value of both potential differences before and after the connection of the known resistance. In this case, the state of the sample does not change depending on the connection / non-connection of the known resistance, so the internal resistance value obtained as described above correctly reflects the state of the sample during potential measurement.

【0014】一方、第3操作時において、電位測定電極
に抵抗値測定電極を接続すると、この場合も電位測定電
極間の電位差が変化する。したがって、抵抗値測定電極
を抵抗とみなしてオームの法則を適用すれば、その接続
前後の両電位差の値と上記第2操作で求めた電位測定電
極の内部抵抗値とから計算により媒液の電気抵抗が求ま
り、その値から電位測定時の試料の状態に見合った媒液
の導電率が求まる。
On the other hand, if the resistance value measuring electrode is connected to the potential measuring electrode during the third operation, the potential difference between the potential measuring electrodes also changes in this case. Therefore, if Ohm's law is applied by regarding the resistance measuring electrode as a resistance, the electrical conductivity of the medium liquid is calculated from the value of both potential differences before and after the connection and the internal resistance value of the potential measuring electrode obtained in the second operation. The resistance is obtained, and from that value, the conductivity of the liquid medium corresponding to the state of the sample at the time of measuring the potential can be obtained.

【0015】こうして、本発明方法によると、電位測定
時に電位測定電極と既知抵抗または抵抗値測定電極との
接続を切り換えて、その時の電位測定電極間の電位差を
測定するだけで、電位測定時における媒液の導電率が求
まるから、簡単な操作で実際の試料の状態に見合った導
電率が再現性良く得られることとなる。また、電位測定
用の回路を用いて電位の変化を見るだけで足り、直接媒
液の電気抵抗を測定しなくてもよいので、従来のように
電位測定用の回路以外に導電率測定用の回路を別途備え
なくてすみ、それだけシステム構成を簡素化することが
できる。
Thus, according to the method of the present invention, the potential measurement electrode can be simply measured by switching the connection between the potential measurement electrode and the known resistance or resistance value measurement electrode at the time of potential measurement, and measuring the potential difference between the potential measurement electrodes at that time. Since the conductivity of the liquid medium is obtained, the conductivity suitable for the actual state of the sample can be obtained with good reproducibility by a simple operation. In addition, it is sufficient to see the change in the potential using the circuit for measuring the potential, and it is not necessary to directly measure the electrical resistance of the liquid medium. It is not necessary to separately provide a circuit, and the system configuration can be simplified accordingly.

【0016】[0016]

【実施例】以下、本発明の実施例について説明する。こ
の実施例は流動電位法でゼータ電位を求める場合に関す
るもので、まず本実施例で使用する装置の構成について
説明する。
EXAMPLES Examples of the present invention will be described below. This embodiment relates to the case where the zeta potential is obtained by the streaming potential method. First, the structure of the device used in this embodiment will be described.

【0017】図1に、その装置の全体構成を示す。同図
に示すように、この装置1は、基本的には、減圧器2を
介して図示しないN2 ガス圧力源(以下、圧力源とい
う)が接続される本体(測定部)3と、アンプユニット
4と、記録計(図例ではX−Yレコーダ)5の3つのユ
ニットによって構成されている。
FIG. 1 shows the overall structure of the apparatus. As shown in the figure, this device 1 basically comprises a main body (measurement section) 3 to which an N 2 gas pressure source (not shown) (hereinafter referred to as a pressure source) is connected via a pressure reducer 2 and an amplifier. It is composed of three units, a unit 4 and a recorder (an XY recorder in the illustrated example) 5.

【0018】本体3には、流動電位(E)を測定するた
めの流動電位測定セル(E測定セルという)6と、この
E測定セル6に液供給通路7を介して供給すべき流動液
(媒液)8を収容する流動液容器9と、液供給通路7を
開閉するコック10と、流動電位測定後にE測定セル6
から排出される媒液を排液通路11を介して回収する排
液用容器12と、圧力源から供給される媒液流動用のN
2 ガスを流動液容器9内に導入するための気体通路13
と、この気体通路13にゲージバルブ14付きの分岐通
路15を介して接続された圧力検出器16と、流動電位
測定後に気体通路13内の圧力を抜くためのパージバル
ブ17と、同気体通路13内の圧力を調整するための圧
力調整バルブ18と、同気体通路13を開閉する開閉バ
ルブ19とが備えられている。
In the main body 3, a streaming potential measuring cell (referred to as an E measuring cell) 6 for measuring a streaming potential (E), and a flowing liquid to be supplied to the E measuring cell 6 via a liquid supply passage 7 ( (Liquid medium) 8, a fluid liquid container 9, a cock 10 for opening and closing the liquid supply passage 7, and an E measurement cell 6 after measuring the flow potential.
And a drainage container 12 for collecting the liquid medium discharged from the liquid via a drainage passage 11, and an N for fluid medium flow supplied from a pressure source.
2 Gas passage 13 for introducing gas into fluid container 9
A pressure detector 16 connected to the gas passage 13 via a branch passage 15 with a gauge valve 14, a purge valve 17 for releasing the pressure in the gas passage 13 after the measurement of the streaming potential, and the inside of the gas passage 13 A pressure adjusting valve 18 for adjusting the pressure of the above and an opening / closing valve 19 for opening / closing the gas passage 13 are provided.

【0019】このうち、圧力検出器16は、ストレイン
ゲージを貼り付けてなるダイヤフラム(図示せず)が内
部に設けられており、そのダイヤフラムが気体通路13
内の圧力により歪んだときに、これに伴うストレインゲ
ージの抵抗変化を測定することにより、気体通路13内
の圧力、つまり流動液容器9内に供給されたN2 ガスの
圧力を検出しうるようになっている。
Among them, the pressure detector 16 is provided with a diaphragm (not shown) having a strain gauge attached thereto, and the diaphragm is the gas passage 13.
When the strain is distorted by the internal pressure, the resistance change of the strain gauge accompanying it is measured so that the pressure in the gas passage 13, that is, the pressure of the N 2 gas supplied into the fluid container 9 can be detected. It has become.

【0020】また、アンプユニット4には、E測定セル
6の後述する各電位測定電極63、63に電線63a、
63bを介して接続され且つ同セルで検出された電位を
記録およびメータ表示するためのインピーダンス変換器
41と、圧力検出器16で検出された圧力を記録表示す
るための圧力用増幅器42とが内蔵されている。ここ
で、流動電位(E)および圧力(P)は本装置のパネル
面に設けられたメータ(図示せず)で表示され、図示の
ように記録計5を接続することにより、E−Pのグラフ
として記録されるようになっている。
In the amplifier unit 4, the electric potential measuring electrodes 63, 63 described later of the E measuring cell 6 are connected to the electric wires 63a,
An impedance converter 41 connected via 63b for recording and metering the potential detected by the same cell, and a pressure amplifier 42 for recording and displaying the pressure detected by the pressure detector 16 are built-in. Has been done. Here, the streaming potential (E) and the pressure (P) are displayed by a meter (not shown) provided on the panel surface of this device, and by connecting the recorder 5 as shown, the E-P It is recorded as a graph.

【0021】一方、E測定セル6には、図2に拡大して
示すように、セルケース61内に固体試料を充填してな
る充填層62と、この充填層62を挟む一対の白金製電
位測定電極63、63とが設けられている。このうち一
対の電位測定電極63、63は、流動液8が充填層62
を通過する方向において互いに対向するように配置され
ており、圧力源から気体通路13を介して流動液容器9
内に供給されるN2 ガスの圧力によって同容器9内の流
動液8をE測定セル6に流したときに、両電極63、6
3間に発生する流動電位を検出するようになっている。
なお、各電位測定電極63と充填層62との間には固体
試料流出防止用のガラスろ紙(図示せず)が設けられて
いる。
On the other hand, in the E measuring cell 6, as shown in an enlarged view in FIG. 2, a filling layer 62 formed by filling a solid sample in a cell case 61 and a pair of platinum potentials sandwiching the filling layer 62. Measuring electrodes 63, 63 are provided. Of the pair of potential measuring electrodes 63, 63, the fluid 8 fills the packed bed 62.
Are arranged so as to oppose each other in the direction of passing through, and the fluid container 9 from the pressure source via the gas passage 13
When the flowing liquid 8 in the same container 9 is caused to flow into the E measuring cell 6 by the pressure of the N 2 gas supplied into the both electrodes 63, 6
The streaming potential generated between 3 is detected.
A glass filter paper (not shown) for preventing solid sample outflow is provided between each potential measuring electrode 63 and the filling layer 62.

【0022】以上の構成に加え、この装置1において
は、流動電位および圧力からゼータ電位を算出する際に
必要となる導電率を求める手段として、次のような構成
が採用されている。すわなち、E測定セル6内に一対の
抵抗測定電極64、64が電位測定電極63、63に対
して並列に設けられている。この抵抗測定電極64、6
4は流動液8の電気抵抗を測定するためのもので、この
うちの一方の電極64が電線64aおよび切り換えスイ
ッチ65を介して一方の電位測定電極63の電線63a
に接続可能とされているとともに、他方の電極64が電
線64bを介して他方の電位測定電極63の電線63b
に接続されている。また、その他方の電位測定電極63
の電線63bと切り換えスイッチ65との間には抵抗値
が既知の抵抗66が配設されている。そして、切り換え
スイッチ65を電線64a側または抵抗66側に切り換
えることで、電位測定電極63、63に対して抵抗測定
電極64、64または抵抗66の一方を並列に接続させ
うるようになっている。なお、切り換えスイッチ65
は、電位測定時には抵抗測定電極64および抵抗66の
いずれにも接続しない中立位置にセットされる。
In addition to the above configuration, the apparatus 1 employs the following configuration as a means for obtaining the electric conductivity required when calculating the zeta potential from the streaming potential and the pressure. That is, a pair of resistance measuring electrodes 64, 64 are provided in parallel with the potential measuring electrodes 63, 63 in the E measuring cell 6. The resistance measuring electrodes 64, 6
Reference numeral 4 is for measuring the electric resistance of the flowing liquid 8. One of the electrodes 64 is an electric wire 63a of one potential measuring electrode 63 via the electric wire 64a and the changeover switch 65.
The other electrode 64 is connected to the electric wire 63b of the other potential measuring electrode 63 via the electric wire 64b.
It is connected to the. The other potential measuring electrode 63
A resistor 66 having a known resistance value is disposed between the electric wire 63b and the changeover switch 65. Then, by switching the changeover switch 65 to the electric wire 64a side or the resistance 66 side, one of the resistance measuring electrodes 64, 64 or the resistance 66 can be connected in parallel to the potential measuring electrodes 63, 63. The changeover switch 65
Is set to a neutral position where it is not connected to either the resistance measuring electrode 64 or the resistance 66 during potential measurement.

【0023】次に、このような装置1を使用して媒液で
ある流動液8の導電率を求める本実施例方法について説
明する。まず、切り換えスイッチ65を中立位置にセッ
トした状態で、E測定セル6内に流動液8を流し込むこ
とにより、同セル内の電位測定電極63、63間に現れ
る電位差つまり流動電位を測定する。この場合、流動電
位を測定する電位測定電極63、63を含む電気回路
は、簡単にすると図3(a)に示すように電池と内部抵
抗とを組合せたものと考えることができる。そこで、こ
の時の電位をEとし、内部抵抗をRx とする。
Next, the method of this embodiment for obtaining the electric conductivity of the fluid 8 which is a liquid medium using the apparatus 1 will be described. First, with the changeover switch 65 set to the neutral position, the flowing liquid 8 is poured into the E measuring cell 6 to measure the potential difference appearing between the potential measuring electrodes 63 in the cell, that is, the flowing potential. In this case, the electric circuit including the potential measuring electrodes 63, 63 for measuring the streaming potential can be considered to be a combination of a battery and an internal resistance as shown in FIG. Therefore, the potential at this time is E and the internal resistance is Rx.

【0024】次に、この状態で図2における切り換えス
イッチ65を既知の抵抗値RS を持った抵抗66側に切
り換えて、電位測定電極63、63と抵抗66とを並列
に接続し、その状態で電位を測定する。この時の電気回
路は、簡単にすると図3(b)に示すようなものとなる
から、この時の電位測定値をER として、オームの法則
を適用すれば、上記内部抵抗Rx は次式(2)で示すよ
うに計算によって求めることができる。
Then, in this state, the changeover switch 65 in FIG. 2 is changed over to the side of the resistor 66 having a known resistance value RS, and the potential measuring electrodes 63, 63 and the resistor 66 are connected in parallel, and in that state. Measure the potential. The electric circuit at this time is as shown in FIG. 3 (b) if it is simplified, and if Ohm's law is applied with the potential measurement value at this time being ER, the internal resistance Rx is It can be calculated as shown in 2).

【0025】[0025]

【数2】 [Equation 2]

【0026】次に、上記切り換えスイッチ65を電線6
4a側に切り換えて、電位測定電極63、63と抵抗測
定電極64、64とを並列に接続し、その状態で電位を
測定する。この時の電気回路は、簡単にすると図3
(c)に示すようなものとなるから、この時の電位測定
値をEλとし、かつ、流動液(媒液)8の間に含む抵抗
測定電極64、64を抵抗と見なしてその抵抗値(流動
液の電気抵抗)をRλとすれば、計算からRλが求めら
れる。この場合、Rλは次式(3)で示される。
Next, the changeover switch 65 is connected to the electric wire 6
Switching to the 4a side, the potential measuring electrodes 63, 63 and the resistance measuring electrodes 64, 64 are connected in parallel, and the potential is measured in that state. The electric circuit at this time is shown in FIG.
Since the result is as shown in (c), the potential measurement value at this time is Eλ, and the resistance measurement electrodes 64, 64 included between the flowing liquid (medium liquid) 8 are regarded as resistance, and the resistance value ( If Rλ is the electric resistance of the flowing liquid, then Rλ can be calculated. In this case, Rλ is expressed by the following equation (3).

【0027】[0027]

【数3】 [Equation 3]

【0028】こうして、流動液8の電気抵抗Rλが求ま
るので、これを導電率の定理に当てはめて流動液8の導
電率λを決定する。すわなち、セル定数をKとして、次
式(4)から導電率λを求める。
In this way, the electric resistance Rλ of the flowing liquid 8 is obtained, and this is applied to the conductivity theorem to determine the electric conductivity λ of the flowing liquid 8. That is, with the cell constant as K, the conductivity λ is obtained from the following equation (4).

【0029】[0029]

【数4】 [Equation 4]

【0030】ここで、セル定数Kは、抵抗測定電極6
4、64に固有の値で、導電率が既知の媒液を用い、あ
らかじめその電気抵抗を測定して決定しておけばすむ。
このような方法によれば、切り換えスイッチ65を中立
位置、既知抵抗66側、抵抗測定電極64側に順次切り
換えて、その時の電位を測定するだけで、容易に、しか
もE測定セル6内の充填層62つまり固体試料を一定の
状態に保ったまま、流動液8の導電率λを求めることが
できる。したがって、電位測定中の試料の状態を正しく
反映した再現性の良い導電率の値が得られる。
Here, the cell constant K is the resistance measuring electrode 6
It is sufficient to use a medium liquid having a specific value for 4 and 64 and a known conductivity, and measure and determine its electric resistance in advance.
According to such a method, the changeover switch 65 is sequentially switched to the neutral position, the known resistance 66 side, and the resistance measuring electrode 64 side, and the potential at that time is measured. The conductivity λ of the fluid 8 can be determined while keeping the layer 62, that is, the solid sample, in a constant state. Therefore, it is possible to obtain a highly reproducible conductivity value that correctly reflects the state of the sample during potential measurement.

【0031】また、電位測定時に流動液8の導電率を求
めることができ、従来のように電位測定後に流動液8を
取り出してその電気抵抗を別途測定する必要がないか
ら、それだけ操作が簡単になるとともに、温度条件が異
なる下で電位測定と導電率測定とを別々に行うといった
ミスを回避することができる。さらに、従来のように電
位測定用の回路以外に導電率測定用の回路を別途備えな
くてすむから、それだけシステム構成を簡素化すること
ができる。
Further, the electric conductivity of the fluid 8 can be obtained at the time of measuring the electric potential, and it is not necessary to take out the fluid 8 after the electric potential measurement and measure the electric resistance separately as in the conventional case. In addition, it is possible to avoid the mistake of separately performing the potential measurement and the conductivity measurement under different temperature conditions. Furthermore, since it is not necessary to separately provide a circuit for measuring conductivity other than the circuit for measuring potential as in the conventional case, the system configuration can be simplified accordingly.

【0032】なお、この実施例では、電位測定電極6
3、63と既知抵抗66または抵抗測定電極64、64
とを並列に接続可能としたが、図4(a)および(b)
に示すうように、内部抵抗RX をもった電位測定電極6
3’、63’に対して既知抵抗(抵抗値RS )または抵
抗測定電極(電気抵抗Rλ)を直列に接続可能な構成と
してもよい。その場合、内部抵抗RX と、流動液(媒
液)8の電気抵抗Rλは、それぞれ次の式(5)および
(6)によって求められる。
In this embodiment, the potential measuring electrode 6
3, 63 and known resistance 66 or resistance measuring electrodes 64, 64
And can be connected in parallel, but FIGS. 4 (a) and 4 (b)
As shown in Fig. 6, a potential measuring electrode 6 having an internal resistance RX.
A known resistance (resistance value RS) or resistance measuring electrode (electrical resistance Rλ) may be connected in series to 3'and 63 '. In that case, the internal resistance RX and the electrical resistance Rλ of the fluid (medium liquid) 8 are obtained by the following equations (5) and (6), respectively.

【0033】[0033]

【数5】 [Equation 5]

【0034】[0034]

【数6】 [Equation 6]

【0035】また、上記実施例では、測定精度を高める
ためにE測定セル6内に抵抗測定電極64、64を設け
たが、この種の抵抗測定電極は必ずしもE測定セル6内
に設ける必要はない。すなわち、流動液8の存在すると
ころであれば、例えば流動液容器9や廃液用容器12の
内部に設けてもよく、あるいは排液通路11内のいずれ
かに設けてもよい。このようにすると、E測定セル6よ
りもスペース的に余裕があるから、E測定セル6内に抵
抗測定電極を設ける場合に比べて、その設置が容易であ
るという利点がある。さらに、測定電極とその引出し電
線などをカートリッジ型のブロックに収め、これをセル
ケースに対して着脱可能にし、分解・調整などを容易に
行わせることもできる。
Further, in the above embodiment, the resistance measuring electrodes 64, 64 are provided in the E measuring cell 6 in order to improve the measuring accuracy, but this kind of resistance measuring electrode does not necessarily have to be provided in the E measuring cell 6. Absent. That is, where the fluid 8 exists, it may be provided inside the fluid container 9 or the waste container 12, or inside the drain passage 11. In this case, since there is a space in the E measurement cell 6, there is an advantage that the resistance measurement electrode can be installed more easily than when the resistance measurement electrode is provided in the E measurement cell 6. Furthermore, the measuring electrode and its lead wire can be housed in a cartridge-type block, which can be attached to and detached from the cell case so that disassembly and adjustment can be easily performed.

【0036】[0036]

【発明の効果】以上のように、本発明によれば、電位測
定時に試料の状態に見合った媒液の導電率が得られると
ともに、電位測定用の回路を用いて電位の変化を見ると
いう簡単な操作を行うだけで、導電率の測定が可能とな
る。したがって、従来のように電位測定後に媒液を取り
出して直接その媒液の電気抵抗を測定しなくてもよく、
電気回路も電位測定用の回路1つですむから、それだけ
システムが簡素化されることとなる。
As described above, according to the present invention, it is possible to obtain the electric conductivity of the medium solution corresponding to the state of the sample at the time of measuring the potential and to easily see the change in the potential by using the circuit for measuring the potential. It is possible to measure the conductivity simply by performing various operations. Therefore, it is not necessary to take out the medium liquid and measure the electric resistance of the medium liquid directly after measuring the potential as in the conventional case.
Since the electric circuit only needs one circuit for measuring the electric potential, the system is simplified accordingly.

【図面の簡単な説明】[Brief description of drawings]

【図1】本発明の実施例で使用した装置の全体構成を示
す構成図である。
FIG. 1 is a configuration diagram showing an overall configuration of an apparatus used in an embodiment of the present invention.

【図2】同装置の流動電位測定セルの周辺部を拡大して
示す拡大図である。
FIG. 2 is an enlarged view showing a peripheral portion of a streaming potential measuring cell of the apparatus in an enlarged manner.

【図3】同装置における電位測定電極を含む電気回路を
簡略化して示す回路図で、(a)は電位測定電極が既知
抵抗および抵抗測定電極のいずれにも接続していない状
態、(b)は電位測定電極に既知抵抗を並列に接続した
状態、(c)は電位測定電極に抵抗測定電極を並列に接
続した状態をそれぞれ示す簡略回路図である。
FIG. 3 is a circuit diagram showing a simplified electric circuit including a potential measuring electrode in the same apparatus, (a) showing a state in which the potential measuring electrode is not connected to a known resistance or a resistance measuring electrode, (b) FIG. 4A is a simplified circuit diagram showing a state in which a known resistance is connected in parallel to a potential measurement electrode, and FIG. 6C is a state in which a resistance measurement electrode is connected in parallel to a potential measurement electrode.

【図4】本発明の他の実施例を示すもので、(a)は電
位測定電極に既知抵抗を直列に接続した状態、(b)は
電位測定電極に抵抗測定電極を直列に接続した状態をそ
れぞれ簡略化して示す電気回路図である。
FIG. 4 shows another embodiment of the present invention, in which (a) is a state in which a known resistance is connected in series to a potential measuring electrode, and (b) is a state in which a resistance measuring electrode is connected in series to the potential measuring electrode. FIG. 3 is an electric circuit diagram showing each of them in a simplified manner.

【符号の説明】[Explanation of symbols]

8・・・媒液(流動液) 62・・・試料(充填層) 63、63’・・・電位測定電極 64・・・抵抗測定電極 66・・・既知の抵抗 RX ・・・電位測定電極を電池と内部抵抗の組合せと考
えた場合の内部抵抗 RS ・・・抵抗の抵抗値 Rλ・・・媒液(流動液)の電気抵抗値
8 ... Medium liquid (fluid liquid) 62 ... Sample (packed bed) 63, 63 '... Potential measuring electrode 64 ... Resistance measuring electrode 66 ... Known resistance RX ... Potential measuring electrode Resistance when considering as a combination of battery and internal resistance RS ・ ・ ・ Resistance value of resistance Rλ ・ ・ ・ Electric resistance value of liquid medium (fluid liquid)

Claims (1)

【特許請求の範囲】[Claims] 【請求項1】 媒液中に粒子または固形の試料が存在す
る系において、その媒液の導電率を測定するにあたり、
試料と媒液との相対運動により生じる電位差を一対の電
位測定電極で測定する第1操作と、前記一対の電位測定
電極に抵抗値が既知の抵抗を並列または直列に接続して
両電極間の電位差を測定する第2操作と、前記一対の電
位測定電極に媒液の電気抵抗を測定するための一対の抵
抗測定電極を並列または直列に接続して前記一対の電位
測定電極間の電位差を測定する第3操作とを行い、第1
および第2操作の測定結果から電位測定電極の内部抵抗
値を求めて、その内部抵抗値と第3操作の測定結果とか
ら媒液の電気抵抗を求め、この電気抵抗を用いて媒液の
導電率を決定することを特徴とする導電率測定方法。
1. In a system in which a particle or solid sample is present in a liquid medium, the conductivity of the liquid medium is measured.
A first operation of measuring a potential difference caused by relative motion between a sample and a medium with a pair of potential measuring electrodes, and a resistor having a known resistance value connected in parallel or in series to the pair of potential measuring electrodes, and between the electrodes. A second operation of measuring the potential difference and a pair of resistance measuring electrodes for measuring the electrical resistance of the medium liquid are connected in parallel or in series to the pair of potential measuring electrodes to measure the potential difference between the pair of potential measuring electrodes. And the third operation
And the internal resistance value of the potential measuring electrode is obtained from the measurement result of the second operation, the electrical resistance of the medium solution is obtained from the internal resistance value and the measurement result of the third operation, and the electrical resistance of the medium solution is calculated using this electrical resistance. A method for measuring conductivity, which comprises determining the conductivity.
JP02967594A 1994-02-28 1994-02-28 Conductivity measurement method Expired - Fee Related JP3166471B2 (en)

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JP02967594A JP3166471B2 (en) 1994-02-28 1994-02-28 Conductivity measurement method

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Application Number Priority Date Filing Date Title
JP02967594A JP3166471B2 (en) 1994-02-28 1994-02-28 Conductivity measurement method

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Publication Number Publication Date
JPH07239313A true JPH07239313A (en) 1995-09-12
JP3166471B2 JP3166471B2 (en) 2001-05-14

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Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6051124A (en) * 1996-09-27 2000-04-18 Nec Corporation Zeta-potential determining apparatus
WO2002065112A1 (en) * 2001-02-14 2002-08-22 Riken Apparatus for detecting interaction between biopolymer and ligand and method thereof
JP2007520709A (en) * 2004-02-03 2007-07-26 オキュセンス,インコーポレーテッド System and method for calibrating an osmotic pressure measuring device
US8020433B2 (en) 2003-03-25 2011-09-20 Tearlab Research, Inc. Systems and methods for a sample fluid collection device
WO2014181632A1 (en) * 2013-05-07 2014-11-13 株式会社日立ハイテクノロジーズ Electrolyte concentration measuring apparatus and measuring method using same
US9335243B2 (en) 2006-12-11 2016-05-10 Tearlab Research, Inc. Systems and methods for collecting tear film and measuring tear film osmolarity
US10018587B2 (en) 2016-04-27 2018-07-10 Panasonic Intellectual Property Management Co., Ltd. Method for determining whether a capillary filled with an electrophoresis medium can be used suitably for electrophoresis
US11536707B2 (en) 2014-09-23 2022-12-27 Tearlab Research, Inc. Systems and methods for integration of microfluidic tear collection and lateral flow analysis of analytes of interest

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6051124A (en) * 1996-09-27 2000-04-18 Nec Corporation Zeta-potential determining apparatus
WO2002065112A1 (en) * 2001-02-14 2002-08-22 Riken Apparatus for detecting interaction between biopolymer and ligand and method thereof
US8020433B2 (en) 2003-03-25 2011-09-20 Tearlab Research, Inc. Systems and methods for a sample fluid collection device
JP2007520709A (en) * 2004-02-03 2007-07-26 オキュセンス,インコーポレーテッド System and method for calibrating an osmotic pressure measuring device
US9335243B2 (en) 2006-12-11 2016-05-10 Tearlab Research, Inc. Systems and methods for collecting tear film and measuring tear film osmolarity
WO2014181632A1 (en) * 2013-05-07 2014-11-13 株式会社日立ハイテクノロジーズ Electrolyte concentration measuring apparatus and measuring method using same
JP2014219246A (en) * 2013-05-07 2014-11-20 株式会社日立ハイテクノロジーズ Electrolytic concentration measuring device and measuring method using the same
CN105164526A (en) * 2013-05-07 2015-12-16 株式会社日立高新技术 Electrolyte concentration measuring apparatus and measuring method using same
US10018585B2 (en) 2013-05-07 2018-07-10 Hitachi High-Technologies Corporation Electrolyte concentration measuring apparatus and measuring method using same
US11536707B2 (en) 2014-09-23 2022-12-27 Tearlab Research, Inc. Systems and methods for integration of microfluidic tear collection and lateral flow analysis of analytes of interest
US10018587B2 (en) 2016-04-27 2018-07-10 Panasonic Intellectual Property Management Co., Ltd. Method for determining whether a capillary filled with an electrophoresis medium can be used suitably for electrophoresis

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