JPH0587602A - Liquid flowmeter - Google Patents
Liquid flowmeterInfo
- Publication number
- JPH0587602A JPH0587602A JP3247536A JP24753691A JPH0587602A JP H0587602 A JPH0587602 A JP H0587602A JP 3247536 A JP3247536 A JP 3247536A JP 24753691 A JP24753691 A JP 24753691A JP H0587602 A JPH0587602 A JP H0587602A
- Authority
- JP
- Japan
- Prior art keywords
- liquid
- electric conductivity
- flow rate
- temperature
- measurement
- 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
Links
Abstract
Description
【０００１】[0001]
【産業上の利用分野】この発明は、液体の流量を測定す
る装置に関し、詳細には、液体クロマトグラフ用流量計
に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for measuring the flow rate of a liquid, and more particularly to a flow meter for a liquid chromatograph.
【０００２】[0002]
【従来の技術】液体クロマトグラフにおいて、液体の流
量を測定する場合、従来は、例えば、液体流路の上流側
で液体に温度変化を与え、この温度変化を流路下流側に
設けたサーミスタ等によって検出することによって求め
ていた。すなわち、液体流路の上流側で与えられた温度
変化は、液体の流量に対応した時間を経過した後に下流
側に伝わるので、この温度変化の位相差を求めることに
よって、液体の流量を求めていた。2. Description of the Related Art Conventionally, when measuring the flow rate of a liquid in a liquid chromatograph, conventionally, for example, a temperature change is applied to the liquid on the upstream side of the liquid flow path, and this temperature change is provided on the downstream side of the flow path. Was sought by detecting by. That is, since the temperature change given on the upstream side of the liquid flow path is transmitted to the downstream side after the time corresponding to the liquid flow rate has passed, the liquid flow rate is obtained by obtaining the phase difference of this temperature change. It was
【０００３】[0003]
【発明が解決しようとする課題】しかし、上記のように
動作する従来の装置は、サーミスタ等の温度検出素子自
身の熱容量や、液体と素子間の熱抵抗の影響を受けるの
で、測定誤差が生じやすく、正確な流量値が求められな
いという問題点がある。また、測定誤差を校正する方法
もあるが、この場合でも室温の変化等の影響を受けやす
いという問題点がある。However, the conventional device operating as described above is affected by the heat capacity of the temperature detecting element itself such as a thermistor and the thermal resistance between the liquid and the element, and therefore, a measurement error occurs. There is a problem that it is easy to obtain an accurate flow rate value. There is also a method of calibrating the measurement error, but even in this case, there is a problem that it is easily affected by a change in room temperature.
【０００４】この発明は、この問題点に着目してなされ
たものであって、より正確に液体の流量を測定すること
の出来る液体流量計を提供することを目的とする。The present invention has been made in view of this problem, and an object thereof is to provide a liquid flow meter capable of measuring the liquid flow rate more accurately.
【０００５】[0005]
【課題を解決するための手段】上記の目的を達成する
為、この発明にかかる液体流量計は、液体流路の特定箇
所に設置され、液体の温度を変化させる温度制御部と、
この温度制御部の設置箇所の流路下流部に設置され、液
体の電気伝導度を測定する１個または複数個の電気伝導
度測定部と、この電気伝導度測定部の測定結果が液体の
温度に対応して変化すること、及び、この電気伝導度の
変化が液体流量に対応して時間的に遅れることに基づい
て液体の流量を求める演算部とを備えている。In order to achieve the above object, a liquid flow meter according to the present invention is installed at a specific position of a liquid flow path, and has a temperature control section for changing the temperature of the liquid.
One or a plurality of electric conductivity measuring units for measuring the electric conductivity of the liquid, which are installed downstream of the flow path of the temperature control unit, and the measurement result of the electric conductivity measuring unit is the liquid temperature. And a calculation unit that determines the flow rate of the liquid based on the fact that the change in the electrical conductivity is delayed in time corresponding to the flow rate of the liquid.
【０００６】[0006]
【作用】温度制御部は、液体流路の特定の箇所に設置さ
れて、流路中の液体に温度変化を与える。電気伝導度測
定部は、この温度制御部の設置箇所の流路下流部に設置
されて、液体の電気伝導度を１箇所または複数箇所で測
定する。The temperature control section is installed at a specific position of the liquid flow path and changes the temperature of the liquid in the flow path. The electric conductivity measuring unit is installed in the downstream portion of the flow path of the installation place of the temperature control unit, and measures the electric conductivity of the liquid at one place or at plural places.
【０００７】演算部は、液体の温度変化に対応して電気
伝導度が変化すること、及び、この電気伝導度の変化が
液体流量に対応して時間的に遅れること、に基づいて液
体の流量を求める。すなわち、流路上流側で液体の温度
（または電気伝導度）が変化し始めてから下流側で電気
伝導度が変化し始めるまでの時間差と、上流側から下流
側までの液体容量とによって液体流量を測定する。The calculation unit calculates the flow rate of the liquid based on the fact that the electric conductivity changes according to the temperature change of the liquid and the change of the electric conductivity is delayed with respect to the liquid flow rate. Ask for. That is, the liquid flow rate is determined by the time difference between the temperature (or the electrical conductivity) of the liquid starting to change on the upstream side of the flow channel and the electrical conductivity starting to change on the downstream side, and the liquid volume from the upstream side to the downstream side. taking measurement.
【０００８】[0008]
【実施例】以下、実施例をもとにして更に詳細に説明す
る。図１は、この発明にかかる液体流量計の一実施例を
示すブロック図である。この液体流量計は、液体流路１
の上流側に設置される温度制御部２と、液体流路１の下
流側に設置さる電気伝導度測定部３と、電気伝導度測定
部３の出力を受けて液体流量を求める演算部４とで構成
されている。Embodiments will be described in more detail below with reference to embodiments. FIG. 1 is a block diagram showing an embodiment of a liquid flow meter according to the present invention. This liquid flow meter has a liquid flow path 1
A temperature control unit 2 installed on the upstream side of the liquid flow path, an electric conductivity measurement unit 3 installed on the downstream side of the liquid flow path 1, and a calculation unit 4 for receiving the output of the electric conductivity measurement unit 3 and calculating the liquid flow rate. It is composed of.
【０００９】ここで、温度制御部２は、液体流路１中の
液体を加熱する加熱部２-1と、加熱部２-1に加わる電源
Ｖと、電源Ｖと加熱部２-1との接続を接断するスイッチ
部２ -3と、スイッチ部２-3をＯＮ／ＯＦＦ制御する加熱
制御部２-2とで構成されている。また、電気伝導度測定
部３は、電気伝導度測定用のセンサ３-1の出力によっ
て、液体流路１中の液体の電気伝導度を測定する。Here, the temperature control unit 2 is provided in the liquid channel 1.
Heating part 2 for heating liquid-1And heating part 2-1Power added to
V, power supply V and heating unit 2-1Switch to disconnect the connection with
Part 2 -3And switch section 2-3Heating to control ON / OFF
Control unit 2-2It consists of and. Also, electric conductivity measurement
The part 3 is a sensor 3 for measuring electric conductivity.-1Depending on the output of
Then, the electrical conductivity of the liquid in the liquid channel 1 is measured.
【００１０】以上の構成の装置において、加熱制御部２
-2は、一定の周期でスイッチ部２-3を接断して、加熱部
２-1を加熱している（図３の（ａ）参照）。その為、流
路中の液体は、一定時間間隔で加熱され、結果として液
体の電気伝導度が一定時間間隔で変化する。ところが、
流路中の液体は下流側に向かって流れているので、下流
側の電気伝導度測定部３で検出される電気伝導度の変化
は、液体の流量に対応した時間だけ遅れることになる
（図３の（ｂ）参照）。つまり、図３の（ａ）と（ｂ）
に図示するように、上流側の温度制御部２で液体の温度
が増加（電気伝導度が増加）し始めてから、下流側の電
気伝導度測定部３で実際に電気伝導度が増加し始めるま
でに時間Ｔ1 のズレがある。In the apparatus having the above structure, the heating control unit 2
-2 and disconnection of the switch unit 2 -3 at a constant period, heating of the heating portion 2 -1 (see FIG. 3 (a)). Therefore, the liquid in the flow path is heated at constant time intervals, and as a result, the electric conductivity of the liquid changes at constant time intervals. However,
Since the liquid in the flow path is flowing toward the downstream side, the change in the electrical conductivity detected by the electrical conductivity measuring unit 3 on the downstream side is delayed by the time corresponding to the flow rate of the liquid (Fig. 3 (b)). That is, (a) and (b) of FIG.
As shown in FIG. 1, from the temperature control unit 2 on the upstream side starts to increase the temperature of the liquid (increases the electrical conductivity) to the actual start of the electrical conductivity measurement on the downstream side electrical conductivity measurement unit 3. There is a time difference of T 1 .
【００１１】そこで、演算部４は、この時間差Ｔ1 と、
温度制御部２の設置点から電気伝導度測定部３の設置点
までの容量Ｖ1 を基にして、液体の流量ＦをＶ1 ／Ｔ1
として求める（Ｆ＝Ｖ1／Ｔ1 ）。図２は、この発明に
係る流量形の別の実施例を示すブロック図である。この
装置は、温度制御部２と、演算部３と、第１と第２の電
気伝導度測定部４，５とで構成されており、電気伝導度
測定部を２つ設けた点に特徴がある。なお、４-1と５-1
は、それぞれ伝導度測定用のセンサであり、温度制御部
２は、図１の場合と同様に一定時間毎に流路の液体を加
熱している（図４の（ａ）参照）。Therefore, the calculation unit 4 calculates the time difference T 1 and
Based on the capacity V 1 from the installation point of the temperature control unit 2 to the installation point of the electrical conductivity measuring unit 3, the flow rate F of the liquid is V 1 / T 1
(F = V 1 / T 1 ). FIG. 2 is a block diagram showing another embodiment of the flow rate type according to the present invention. This device comprises a temperature control unit 2, a calculation unit 3, and first and second electric conductivity measuring units 4 and 5, and is characterized in that two electric conductivity measuring units are provided. is there. 4 -1 and 5 -1
Are conductivity measuring sensors, respectively, and the temperature control unit 2 heats the liquid in the flow path at regular time intervals as in the case of FIG. 1 (see (a) of FIG. 4).
【００１２】図２の装置において、第１と第２の電気伝
導度測定部４，５の間の容量をＶ2 とすると、第１の電
気伝導度測定部４において電気伝導度が増加し始めてか
ら、第２の電気伝導度測定部５において電気伝導度が増
加し始めるまでの間には、容量Ｖ2 に対応する時間の差
が生じる（図４の（ｂ）と（ｃ）参照）。従って、演算
部３は、この時間差Ｔ2 を求めてＶ2 ／Ｔ2 の計算によ
って液体流量を求める（Ｆ＝Ｖ2 ／Ｔ2 ）。In the apparatus of FIG. 2, when the capacitance between the first and second electric conductivity measuring units 4 and 5 is V 2 , the electric conductivity of the first electric conductivity measuring unit 4 starts to increase. Therefore, there is a time difference corresponding to the capacitance V 2 between the time when the electric conductivity of the second electric conductivity measuring unit 5 starts to increase (see (b) and (c) of FIG. 4). Therefore, the calculation unit 3 obtains this time difference T 2 and obtains the liquid flow rate by calculating V 2 / T 2 (F = V 2 / T 2 ).
【００１３】図２に示す実施例の場合、測定結果には、
加熱部２-1に電源Ｖが印加されてから実際に液体の温度
が増加し始めるまでの、時間的遅れが影響しないので、
実施例１の場合より測定精度が高い。図５は、この発明
に係る液体流量計を用いた液体クロマトグラフシステム
を図示したものである。In the case of the embodiment shown in FIG.
Since the time delay from when the power source V is applied to the heating unit 2-1 to when the temperature of the liquid actually starts to increase does not affect,
The measurement accuracy is higher than that of the first embodiment. FIG. 5 illustrates a liquid chromatograph system using the liquid flow meter according to the present invention.
【００１４】ポンプ２１より注入された液体は、液体流
路２２を流れてゆき、その過程で試料がサイプルインジ
ェクタ２３より注入される。そして、それらはカラム２
４を経過した後、分析用の検出器２５に導かれて、流量
計２６に至る。なお、高速液体クロマトグラフ（ＨＰＬ
Ｃ）は、通常、移動相にバッファを加える場合が多く、
ほとんどのＨＰＬＣの分析には、本発明に係る液体流量
計を使用することができる。The liquid injected from the pump 21 flows through the liquid flow path 22, and the sample is injected from the siple injector 23 in the process. And those are column 2
After 4 times, it is led to the detector 25 for analysis and reaches the flowmeter 26. In addition, high performance liquid chromatograph (HPL
C) usually adds a buffer to the mobile phase,
The liquid flow meter according to the present invention can be used for most HPLC analyzes.
【００１５】[0015]
【発明の効果】以上説明したように、この発明に係る液
体流量計では、温度変化に対応して電気伝導度が変化す
ること、及び、液体流量に対応して電気伝導度が時間的
遅れて変化すること、を利用して液体の流量を測定して
いる。そして、電気伝導度の測定には、温度測定におけ
るような時間的遅れがないので精度の高い流量測定がで
きる。As described above, in the liquid flowmeter according to the present invention, the electric conductivity changes in accordance with the temperature change, and the electric conductivity is delayed in time corresponding to the liquid flow rate. The change is used to measure the liquid flow rate. Since there is no time delay in measuring the electric conductivity as in the temperature measurement, the flow rate can be measured with high accuracy.
【００１６】また、この液体流量計をＨＰＬＣのＧＰＣ
分析等に使用した場合は、分子量測定の精度が向上す
る。Further, this liquid flow meter is used as a GPC for HPLC.
When used for analysis or the like, the accuracy of molecular weight measurement is improved.
【図１】この発明の一実施例である液体流量計を示すブ
ロック図である。FIG. 1 is a block diagram showing a liquid flow meter according to an embodiment of the present invention.
【図２】この発明の別の実施例である液体流量計を示す
ブロック図である。FIG. 2 is a block diagram showing a liquid flow meter according to another embodiment of the present invention.
【図３】図１の装置の各部の波形を示す図面である。FIG. 3 is a diagram showing waveforms of various parts of the apparatus of FIG.
【図４】図２の装置の各部の波形を示す図面である。FIG. 4 is a diagram showing waveforms of various parts of the apparatus of FIG.
【図５】液体クロマトグラムシステムの構成図を図示し
たものである。FIG. 5 is a diagram showing the configuration of a liquid chromatogram system.
１ 液体流路 ２ 温度制御部 ３ 演算部 ４、５ 電気伝導度測定部 Ｖ2 液体容量1 Liquid flow path 2 Temperature control unit 3 Computing unit 4, 5 Electrical conductivity measuring unit V 2 Liquid capacity
Claims (1)
度を変化させる温度制御部と、 この温度制御部の設置箇所の流路下流部に設置され、液
体の電気伝導度を測定する１個または複数個の電気伝導
度測定部と、 この電気伝導度測定部の測定結果が液体の温度に対応し
て変化すること、及び、この電気伝導度の変化が液体流
量に対応して時間的に遅れることに基づいて液体の流量
を求める演算部とを備えることを特徴とする液体流量
計。1. A temperature control unit installed at a specific location of a liquid flow path to change the temperature of the liquid, and a temperature control unit installed downstream of the flow path where the temperature control unit is installed to measure the electrical conductivity of the liquid. One or a plurality of electric conductivity measuring units, the measurement result of the electric conductivity measuring unit changes according to the temperature of the liquid, and the change of the electric conductivity corresponds to the liquid flow rate. A liquid flow meter, which comprises: a calculation unit that obtains the flow rate of the liquid based on a delay in time.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP24753691A JP2946866B2 (en) | 1991-09-26 | 1991-09-26 | Liquid flow meter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP24753691A JP2946866B2 (en) | 1991-09-26 | 1991-09-26 | Liquid flow meter |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0587602A true JPH0587602A (en) | 1993-04-06 |
| JP2946866B2 JP2946866B2 (en) | 1999-09-06 |
Family
ID=17164960
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP24753691A Expired - Fee Related JP2946866B2 (en) | 1991-09-26 | 1991-09-26 | Liquid flow meter |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2946866B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103148900A (en) * | 2012-12-04 | 2013-06-12 | 山东迪泽仪表科技有限公司 | Natural gas trade flow meter |
-
1991
- 1991-09-26 JP JP24753691A patent/JP2946866B2/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103148900A (en) * | 2012-12-04 | 2013-06-12 | 山东迪泽仪表科技有限公司 | Natural gas trade flow meter |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2946866B2 (en) | 1999-09-06 |
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