JP3381747B2 - Method and apparatus for measuring solution concentration - Google Patents
Method and apparatus for measuring solution concentrationInfo
- Publication number
- JP3381747B2 JP3381747B2 JP30650194A JP30650194A JP3381747B2 JP 3381747 B2 JP3381747 B2 JP 3381747B2 JP 30650194 A JP30650194 A JP 30650194A JP 30650194 A JP30650194 A JP 30650194A JP 3381747 B2 JP3381747 B2 JP 3381747B2
- Authority
- JP
- Japan
- Prior art keywords
- detector
- concentration
- solution
- ultrasonic wave
- propagation time
- 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 - Fee Related
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2291/00—Indexing codes associated with group G01N29/00
- G01N2291/02—Indexing codes associated with the analysed material
- G01N2291/028—Material parameters
- G01N2291/02809—Concentration of a compound, e.g. measured by a surface mass change
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2291/00—Indexing codes associated with group G01N29/00
- G01N2291/02—Indexing codes associated with the analysed material
- G01N2291/028—Material parameters
- G01N2291/02818—Density, viscosity
Landscapes
- Investigating Or Analyzing Materials By The Use Of Ultrasonic Waves (AREA)
Description
【0001】[0001]
【産業上の利用分野】本発明は超音波を用いて溶液濃度
を測定する方法および溶液濃度測定装置(超音波濃度
計)に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring a solution concentration using ultrasonic waves and a solution concentration measuring device (ultrasonic densitometer).
【0002】[0002]
【従来の技術】溶液の超音波伝播時間から該溶液の濃度
を測定する方法は化学装置などで一般に行われており、
測定方法および装置における種々の提案が行われてい
る。たとえば特公昭62−35063号には被測定溶液
に超音波を放射し、該被測定溶液における超音波伝播速
度またはその逆数である音響学的パラメーターを測定
し、電子回路により発生させる該被測定溶液と等しい温
度の基準液に対応する音響学的パラメーターと該被測定
溶液の温度情報により補正して溶液濃度を測定する方法
が記載されている。また特公平4−8746号には該被
測定溶液の超音波伝播速度と温度の関数式により濃度を
測定する装置が記載されている。2. Description of the Related Art A method for measuring the concentration of a solution from the ultrasonic wave propagation time of the solution is generally performed in a chemical device or the like,
Various proposals have been made in measurement methods and devices. For example, in Japanese Examined Patent Publication No. 62-35063, the solution to be measured is generated by irradiating an ultrasonic wave to the solution to be measured, measuring the acoustic wave velocity in the solution to be measured or its reciprocal, and generating it by an electronic circuit. There is described a method of measuring the solution concentration by correcting it with an acoustic parameter corresponding to a reference liquid having a temperature equal to and the temperature information of the solution to be measured. Japanese Patent Publication No. 4-8746 discloses an apparatus for measuring the concentration of a solution to be measured by a function formula of ultrasonic wave propagation velocity and temperature.
【0003】[0003]
【発明が解決しようとする課題】超音波伝播時間測定回
路を用いて溶液の濃度を測定する方法は、その応答時間
が速く、電子回路を用いて電算機制御などに容易に利用
し得ることから、最近多く用いられている。従来技術の
濃度測定方法は、何れも該被測定溶液の検出器における
超音波伝播時間と超音波伝播路距離から超音波伝播速度
またはその逆数である音響学的パラメーターを測定し、
基準液に対応する超音波伝播速度または音響学的パラメ
ーターと温度情報により濃度を測定するものである。The method of measuring the concentration of a solution using an ultrasonic wave propagation time measuring circuit has a fast response time and can be easily used for computer control and the like using an electronic circuit. , Has been widely used recently. The concentration measuring method of the prior art is to measure the acoustic parameter which is the ultrasonic wave propagation velocity or its inverse from the ultrasonic wave propagation time and the ultrasonic wave propagation path distance in the detector of the solution to be measured,
The concentration is measured by ultrasonic wave propagation velocity or acoustic parameter corresponding to the reference liquid and temperature information.
【0004】このような超音波伝播速度等を用いる方法
は、超音波伝播速度の計測精度を高めるために被測定溶
液の超音波伝播路距離が正確に計測されていることが前
提となる。しかしながら該超音波伝播路距離は、この超
音波の往復長、反射面の直角度、超音波受発射素子の取
付角度などの加工精度、使用中のセルの膨張、セルの汚
れによる往復長の実質的な変化などにより、検出器の伝
播経路長を常時正確に計測して把握するのが困難なこと
が、超音波伝播速度の計測精度の向上を阻む大きな原因
となっている。The method using such ultrasonic wave propagation velocity is premised on that the ultrasonic wave propagation path distance of the solution to be measured is accurately measured in order to improve the measurement accuracy of the ultrasonic wave propagation velocity. However, the ultrasonic propagation path distance is substantially the reciprocal length of this ultrasonic wave, the processing accuracy such as the perpendicularity of the reflecting surface, the mounting angle of the ultrasonic receiving and emitting element, the expansion of the cell in use, and the reciprocal length due to the contamination of the cell. It is difficult to constantly measure and grasp the propagation path length of the detector due to a change in the environment, which is a major cause of hindering the improvement of the measurement accuracy of the ultrasonic propagation velocity.
【0005】すなわち超音波伝播時間は検出器セルにお
いて、通常、超音波発射素子より超音波を対向面に反射
させて超音波受信素子に戻るまでの液中伝播時間が測定
されることから、超音波伝播路距離は検出器セルにおけ
る超音波受発信素子より対向面までの液中距離の2倍
(往復長)となる。この各検出器毎の超音波伝播路距離
を製作時に或いは使用中に正確に計測することは、次の
ような点から極めて困難である。
A)検出器長さ、発射面・反射面の直角度、超音波受発
射素子の取付角度などの製作加工精度に限界があり、ま
たこれらを総合した超音波伝播路距離の絶対値を計測す
る場合の誤差もある。
B)使用中の経時的な伝播路距離の変化としては、超
音波受発射面や反射面がスラリー等で削られたり、異物
の付着による実質的な寸法の変化があり、温度変化に
伴う検出器の寸法の変化もあり、特に検出器の材質がプ
ラステックの場合に温度変化に伴う寸法の変化が大き
い、被測定液の影響による検出器材質の膨潤・収縮な
どが挙げられる。That is, the ultrasonic wave propagation time is usually measured in the detector cell by measuring the ultrasonic wave propagation time in the liquid before the ultrasonic wave is reflected from the ultrasonic wave emitting element to the opposite surface and returned to the ultrasonic wave receiving element. The sound wave propagation path distance is twice the liquid distance from the ultrasonic wave transmitting / receiving element in the detector cell to the facing surface (reciprocating length). It is extremely difficult to accurately measure the ultrasonic wave propagation path distance of each detector during manufacture or during use. A) There is a limit to the manufacturing processing accuracy such as the detector length, the perpendicularity of the emitting surface / reflecting surface, and the mounting angle of the ultrasonic receiving / emitting element, and the absolute value of the ultrasonic propagation path distance that combines these is measured. There is an error in some cases. B) As a change in propagation path distance over time during use, ultrasonic wave receiving and emitting surfaces and reflective surfaces are scraped with slurry, etc. There are also changes in the dimensions of the detector, and especially when the detector material is plastic, the changes in dimensions due to temperature changes are large, and the swelling / contraction of the detector material due to the influence of the liquid to be measured can be mentioned.
【0006】また電子回路を持つ測定器類は、
A)電源電圧、周囲温度、湿度、振動、部品経年変化、
劣化などの要因により、測定値のドリフト(ふらつき、
周期的変動、一定方向の移動など)が生じる、
B)測定器の構成要素の検出器、変換器、基準電圧発生
器、基準周波数発生器および補正演算器などの部分に誤
差(定常誤差)が必ず含まれている
のが一般的であり、測定精度を左右する大きな要因とな
る。The measuring instruments having an electronic circuit are as follows: A) power supply voltage, ambient temperature, humidity, vibration, aging of parts,
Due to factors such as deterioration, drift of measured values (stability,
Periodic fluctuations, movements in a certain direction, etc.) B) Errors (steady-state errors) occur in the detector, converter, reference voltage generator, reference frequency generator and correction calculator of the components of the measuring instrument. It is generally included, and it is a major factor that affects the measurement accuracy.
【0007】濃度測定値の精度を高めるために、前述の
特公昭62−35063号においては被測定溶液と標準
溶液の音響学的パラメーターを用い、特公平4−874
6号では超音波伝播速度と温度の関数式が用いられてい
るが、これらの方法は何れも超音波伝播速度に対して温
度補正を行うのみであるから、前述の如く超音波伝播速
度の測定値には伝播路長さの誤差が含まれており、また
測定回路における上記のドリフトや定常誤差は回避され
ず、測定精度に限界がある。In order to improve the accuracy of the concentration measurement value, the acoustic parameters of the solution to be measured and the standard solution are used in Japanese Patent Publication No. 62-35063, which is disclosed in Japanese Examined Patent Publication No. 4-874.
In No. 6, a function formula of ultrasonic wave propagation velocity and temperature is used, but since all of these methods only perform temperature correction on the ultrasonic wave propagation velocity, the ultrasonic wave propagation velocity is measured as described above. The value includes an error in the propagation path length, and the above drift and steady-state error in the measurement circuit cannot be avoided, and the measurement accuracy is limited.
【0008】すなわち従来の方法ではこのようにして温
度補正だけに着目した方法であり、上記の超音波伝播速
度の測定値の誤差や、電子回路におけるドリフトおよび
定常誤差が残ることになる。本発明の目的は超音波伝播
時間測定回路を用いた濃度測定装置における以上の如き
課題を解決し、溶液濃度を高精度で測定する方法および
装置を提供することである。That is, in the conventional method, only the temperature correction is focused in this way, and the error in the measured value of the ultrasonic wave propagation velocity, the drift and the steady error in the electronic circuit remain. An object of the present invention is to solve the above problems in a concentration measuring device using an ultrasonic wave propagation time measuring circuit, and to provide a method and a device for measuring a solution concentration with high accuracy.
【0009】[0009]
【課題を解決するための手段】発明者は超音波伝播時間
測定回路を用いた濃度測定装置における以上の如き課題
について鋭意検討した結果、溶液の超音波伝播時間検
出器(検出器と称す)において複数個の既知濃度および
基準液の溶液の超音波伝播時間を測定することにより、
これらの関係式から超音波伝播速度を用いることなしに
被測定液の濃度を求めることができ、これにより伝播路
長さの誤差が解消されて測定精度を高めることができる
こと、該測定法で複数個の超音波検出器を用いる場合
には、超音波回路以降の電子回路を各検出器に共通に使
用すれば電子回路におけるドリフトおよび定常誤差を実
質的に著しく低下できること、一定時間毎、或いは特
定指令で上記の超音波伝播路時間の補正係数を計算し記
憶する機構を組込むことにより使用中の経時的な伝播距
離の変化による誤差を補正し、常に高測定精度が得られ
るようになることから、これらの結果として、滴定分析
計に匹敵する高精度の濃度測定値が得られること、また
基準液の超音波伝播時間と温度の、初期計測値と使用
後の該計測値とからも、測定器の変動の程度を具体的に
把握できること、更に基準液用検出器と被測定液用検出
器を複数用いて、それらに共通の電子回路で情報処理す
ることにより、1台の分析計で多点の分析が可能とな
り、経済的にも優れた分析計となることを見出し、本発
明に到達した。Means for Solving the Problems As a result of intensive studies on the above problems in a concentration measuring apparatus using an ultrasonic propagation time measuring circuit, the inventor has found that an ultrasonic wave propagation time detector for a solution (referred to as a detector) By measuring the ultrasonic propagation time of a solution of several known concentrations and reference solution,
It is possible to obtain the concentration of the liquid to be measured from these relational expressions without using the ultrasonic wave propagation velocity, thereby eliminating the error in the propagation path length and improving the measurement accuracy. When using multiple ultrasonic detectors, if an electronic circuit after the ultrasonic circuit is commonly used for each detector, the drift and steady-state error in the electronic circuit can be substantially significantly reduced, at fixed time intervals, or at a specific time. By incorporating a mechanism to calculate and store the above-mentioned ultrasonic propagation path time correction coefficient by command, the error due to the change in propagation distance over time during use is corrected, and high measurement accuracy can always be obtained. , As a result of these, it is possible to obtain a highly accurate concentration measurement value comparable to that of a titration analyzer, and also the ultrasonic propagation time and temperature of the reference liquid, from the initial measurement value and the measurement value after use, The degree of fluctuation of the measuring instrument can be grasped concretely, and moreover, by using multiple detectors for the reference liquid and the detector for the measured liquid, and processing information with a common electronic circuit for them, one analyzer can be used. The present invention has been accomplished by finding that it is possible to perform multi-point analysis and becomes an economically excellent analyzer.
【0010】即ち本発明は、溶液の超音波伝播時間検
出器において複数個の既知濃度の溶液および基準液の超
音波伝播時間、または更に温度を測定して関係式を作成
し、超音波伝播速度を用いることなしに該関係式から被
測定液の濃度を求めることを特徴とする溶液濃度の測定
方法、複数個の検出器を用いての方法を行う場合に
共通の超音波回路を用いる方法、特定時間または特定
の指令で既知濃度の溶液を検出器に通過して超音波伝播
時間を測定し、該関係式を補正するないしの方法、
、またはの機能を有する溶液濃度の測定装置およ
び、基準液または既知濃度の溶液の超音波伝播時間と温
度を測定して関係式を作成し、基準液または既知濃度の
溶液の超音波伝播時間の測定情報と、関係式からの超音
波伝播時間から測定装置の狂いを監視する手段を有する
溶液濃度の測定装置である。That is, according to the present invention, the ultrasonic wave propagation time detector measures the ultrasonic wave propagation time of a plurality of solutions having a known concentration and a reference solution, or further measures the temperature to prepare a relational expression to determine the ultrasonic wave propagation velocity. A method of measuring a solution concentration, which is characterized by obtaining the concentration of a liquid to be measured from the relational expression without using a method, a method of using a common ultrasonic circuit when performing a method using a plurality of detectors, A method of correcting the relational expression by measuring the ultrasonic propagation time by passing a solution having a known concentration through a detector at a specific time or a specific command,
, Or a solution concentration measuring device having the function of, and measuring the ultrasonic wave propagation time and temperature of the reference solution or solution of known concentration to create a relational expression, and calculate the ultrasonic wave propagation time of the reference solution or solution of known concentration. It is a solution concentration measuring device having means for monitoring the deviation of the measuring device from the measurement information and the ultrasonic wave propagation time from the relational expression.
【0011】本発明における複数個の既知濃度溶液およ
び基準液の超音波伝播時間を測定してこれらの関係式か
ら超音波伝播速度を用いることなしに被測定液の濃度を
求める方法は特に制限されず、検出器が一個の場合と複
数個の場合があり、例えば一定温度で複数個の既知濃度
と基準液の溶液の伝播時間比や時間差の関係式から求め
る方法等、種々の方法が挙げられる。以下、その具体例
を説明する。なお以下の説明は複数個の既知濃度溶液お
よび基準液の超音波伝播時間に温度因子を加えた関係式
とするが、恒温槽等を使用して被測定溶液を常に特定の
温度に保って濃度測定を行う場合は温度補正に係わる事
項は不要であり、より簡単な関係式で精密な濃度計測を
行うことができる。The method of measuring the ultrasonic wave propagation times of a plurality of solutions having a known concentration and the reference solution in the present invention and obtaining the concentration of the liquid to be measured from these relational expressions without using the ultrasonic wave propagation velocity is particularly limited. However, there may be one detector or a plurality of detectors, for example, various methods such as a method of obtaining from a relational expression of a propagation time ratio or a time difference between a plurality of known concentrations and a solution of a reference solution at a constant temperature can be mentioned. . A specific example will be described below. Note that the following explanation is a relational expression in which a temperature factor is added to the ultrasonic wave propagation time of a plurality of solutions of known concentration and reference solution, but the solution to be measured is always kept at a specific temperature using a thermostat or the like to determine the concentration. When the measurement is performed, the matters relating to the temperature correction are unnecessary, and the precise concentration measurement can be performed with a simpler relational expression.
【0012】なお以下の説明は既知濃度液及び被測定液
は同じ物質の水溶液であり、基準液に純水を用いた場合
とする。本発明の方法において既知濃度溶液の1つは、
濃度計の最大目盛りと同じかそれに極めて近い濃度の液
が望ましく、基準液には濃度0%又は100%の溶液が
選定されるのが一般的であり、水溶液を測定する場合に
は基準液として超純水等が用いられる。In the following description, the known concentration liquid and the liquid to be measured are aqueous solutions of the same substance, and pure water is used as the reference liquid. One of the solutions of known concentration in the method of the present invention is
A liquid with a concentration equal to or extremely close to the maximum scale of the densitometer is desirable, and a 0% or 100% concentration solution is generally selected as the reference liquid. When measuring an aqueous solution, it is used as the reference liquid. Ultrapure water or the like is used.
【0013】(検出器が1個の場合の測定方法)
仮に基準とする検出器Sに、基準液と複数個の既知濃
度(CN )溶液を順次導き、使用範囲内の上限と下限を
含む幾つかの温度レベル(TS )に対応する基準液の伝
播時間tS と既知濃度液の伝播時間tN を測定する。
CN 、TS 、tS 、tN の下記の関係式を求め、計測
装置内に記憶させる。
ア)検出器の基準液の伝播時間と温度の関係式 tS =F(TS ) (1-1)
イ)RS とTS とCN との関係式 CN =F(RS 、TS ) (1-2)
ウ)DtS とTS とCN との関係式 CN =F(DtS 、TS ) (1-3)
但し、伝播時間比 RS =tN /tS (1-2)'
伝播時間差 DtS =|tS −tN | (1-3)'
なお濃度測定には (1-1)式と共に、 (1-2)式の時間比方
式、 (1-3)式の時間差方式の何れかの関係式からも求め
られる。
未知濃度液の濃度測定には、被測定液を検出器に導き
温度TX と伝播時間tXを計測し、同温度に於ける基準
液の伝播時間tS に相当する値を (1-1)式より求め、次
にRS =tX /tS 又はDtS =|tS ーtX |を計算
し、 (1-2)式の時間比方式又は (1-3)式の時間差方式の
計算式から被測定液の濃度を求める。このRS を使用す
る時間比方式及びDtS を使用する時間差方式の何れ
も、伝播路長の計測の必要が無しに高精度の濃度測定が
できる。(Measurement Method When One Detector is Used) A reference liquid and a plurality of solutions of known concentration (C N ) are sequentially introduced to a detector S serving as a reference, and the upper limit and the lower limit within the use range are included. The propagation time t S of the reference liquid and the propagation time t N of the known concentration liquid corresponding to several temperature levels (T S ) are measured. The following relational expressions of C N , T S , t S , and t N are obtained and stored in the measuring device. A) Relational expression between the propagation time and temperature of the reference liquid of the detector t S = F (T S ) (1-1) b) Relational expression between R S , T S and C N C N = F (R S , T S ) (1-2) C) Relational expression between Dt S , T S and C N C N = F (Dt S , T S ) (1-3) where propagation time ratio R S = t N / t S (1-2) 'Propagation time difference Dt S = | t S -t N | (1-3)' For concentration measurement, along with equation (1-1), the time ratio method of equation (1-2), ( It can also be obtained from any of the relational expressions of the time difference method of equation 1-3). To measure the concentration of an unknown concentration liquid, the measured liquid is introduced into a detector, the temperature T X and the propagation time t X are measured, and the value corresponding to the propagation time t S of the reference liquid at the same temperature is calculated as (1-1 ), Then calculate R S = t X / t S or Dt S = | t S -t X |, and calculate the time ratio method of the equation (1-2) or the time difference method of the equation (1-3). Obtain the concentration of the solution to be measured from the formula. Both the time ratio method using R S and the time difference method using Dt S can perform highly accurate concentration measurement without the need to measure the propagation path length.
【0014】上記の計算方法では、基準液の温度が同じ
でも超音波伝播経路長が異なる検出器を使用すると (1-
1)式が変わり、濃度と温度が同じ被測定溶液の場合でも
伝播時間tN が異ってDtS の値も変わることになる。
すなわち伝播路長が異なる毎に該関係式の基本部分が異
なるので検出器毎の関係式が必要となるが、これ対して
は次に示すように伝播距離に関係する補正係数を導入す
ることにより解決される。In the above calculation method, if the detectors having the same reference liquid temperature but different ultrasonic wave propagation path lengths are used (1-
The equation (1) changes, and even in the case of the solution to be measured having the same concentration and temperature, the value of Dt S changes due to the different propagation time t N.
That is, since the basic part of the relational expression is different every time the propagation path length is different, a relational expression for each detector is required. However, by introducing a correction coefficient related to the propagation distance as shown below, Will be resolved.
【0015】伝播時間比RS による (1-2)式の時間比方
式の場合には、ある温度の任意濃度の液を、仮に基準と
する検出器Sで測定した伝播時間がtS 、伝播経路長が
検出器SのK倍の検出器Xで測定した伝播時間がtX の
場合、K=tX /tS からKを求めれば、伝播路長が検
出器SのK倍の検出器Xでと同じ測定をすると伝播時
間は全てK倍となる。(1-2)'式の検出器SによるRS =
tN /tS に相当する検出器Xの時間比は(K*tN )
/(K*tS )=tN /tS であるから、RS の値は伝
播路長の長短には左右されない溶液種類に固有のファク
ターである。またRS =(K*tN )/(K*tS )=
(1/K)*(K*tN /tS )において、〔K*
tN 〕は検出器Xの直接計測値と同じであり、tS は
(1-1)式から導かれることに着目すると、検出器Xの計
測データからRS を得ることができ、濃度測定が可能と
なるすなわち検出器Xで未知濃度溶液を測定する時は、
先ず該溶液の温度TX と伝播時間tX を計測し、 (1-1)
式の温度項にTX を代入して検出器Sの温度TX におけ
る基準液伝播時間tS を計算し、補正伝播時間比RS =
(1/K)*tX /tS を計算し、次に (1-2)式のRS
および温度項に該数値を代入して濃度が得られる。In the case of the time ratio method of the formula (1-2) based on the propagation time ratio R S , the propagation time t S of the liquid having an arbitrary concentration at a certain temperature, which is measured by the temporary reference detector S , When the propagation time measured by the detector X whose path length is K times that of the detector S is t X , if K is calculated from K = t X / t S , the detector whose propagation path length is K times that of the detector S is obtained. If the same measurement as in X is performed, the propagation times are all K times. R S = by the detector S of the formula (1-2) '
The time ratio of the detector X corresponding to t N / t S is (K * t N )
Since / (K * t S ) = t N / t S , the value of R S is a factor specific to the type of solution that is not affected by the length of the propagation path. Also, R S = (K * t N ) / (K * t S ) =
In (1 / K) * (K * t N / t S ), [K *
t N ] is the same as the direct measurement value of the detector X, and t S is
Focusing on the fact that it is derived from the equation (1-1), R S can be obtained from the measurement data of the detector X, and the concentration can be measured. That is, when measuring the unknown concentration solution with the detector X,
First, the temperature T X and the propagation time t X of the solution are measured, and (1-1)
The reference liquid propagation time t S at the temperature T X of the detector S is calculated by substituting T X in the temperature term of the equation, and the corrected propagation time ratio R S =
Calculate (1 / K) * t X / t S , then R S in equation (1-2)
The concentration is obtained by substituting the numerical value for the temperature term.
【0016】DtS による (1-3)式の時間差方式の場合
には、 (1-2)式の時間比方式の場合と同様にKを求め、
伝播路長が検出器SのK倍の検出器Xで同様に測定をす
ると伝播時間は全てK倍となる。従って検出器Sによる
DtS =|tS −tN |に相当する検出器Xの時間差は
|K*tS −KtN |=K*|tS −tN |=K*Dt
S となって、伝播路長の倍数となり、またDtS =|t
S −tN |=|tS −(1/K)*K*tN |となる。
ここで(K*tN )は検出器Xの直接の計測値と同じで
あり、tS は (1-1)式から導かれることから、検出器X
のデータよりDtS を得ることができ、濃度測定が可能
となるすなわち検出器Xで未知濃度溶液を測定する時
は、該溶液の温度TX と伝播時間tX を測定し、 (1-1)
式の温度項にTX を代入して検出器Sの温度TX におけ
る基準液伝播時間tS を計算し、補正伝播時間差DtS
=|tS −(1/K)*tX |を求め、 (1-3)式のDt
S および温度項に該数値を代入して濃度が得られる。In the case of the time difference method of the equation (1-3) based on Dt S , K is obtained in the same manner as in the time ratio method of the equation (1-2),
When the same measurement is performed by the detector X whose propagation path length is K times that of the detector S, the propagation time becomes K times. Therefore, the time difference of the detector X corresponding to Dt S = | t S −t N | by the detector S is | K * t S −Kt N | = K * | t S −t N | = K * Dt
S , which is a multiple of the propagation path length, and Dt S = | t
S −t N | = | t S − (1 / K) * K * t N |.
Here, (K * t N ) is the same as the direct measurement value of the detector X, and t S is derived from the equation (1-1).
It is possible to obtain Dt S from the data of (1), and it becomes possible to measure the concentration, that is, when measuring a solution of unknown concentration with the detector X, the temperature T X of the solution and the propagation time t X are measured, and (1-1 )
The reference liquid propagation time t S at the temperature T X of the detector S is calculated by substituting T X into the temperature term of the equation, and the corrected propagation time difference Dt S is calculated.
= | T S − (1 / K) * t X | and obtain Dt of equation (1-3)
The concentration is obtained by substituting the numerical values for the S and temperature terms.
【0017】このように基準液と被測定溶液の伝播時間
差または伝播時間比に基づく何れの方式においても、検
出器の伝播路長がどのように変わろうとも、補正係数K
の導入により、検出器毎に別々の関係式を求める必要は
無くなる。検出器が1個で測定する場合には超音波伝播
時間測定回路や演算回路などが被測定液と基準液で全て
共通であり、データ採取に関して電子回路におけるドリ
フトおよび定常誤差の影響が小さい。As described above, in any method based on the propagation time difference or the propagation time ratio between the reference solution and the solution to be measured, no matter how the propagation path length of the detector changes, the correction coefficient K is obtained.
With the introduction of, it becomes unnecessary to obtain a separate relational expression for each detector. When measuring with only one detector, the ultrasonic wave propagation time measuring circuit, the arithmetic circuit, and the like are common to the liquid to be measured and the reference liquid, and the influence of drift and steady-state error in the electronic circuit on data collection is small.
【0018】(複数の検出器の場合の測定方法)同一の検
出器で基準液を切替えることは検出器の洗浄を完全に行
う必要があり時間もかかるので相当煩雑であり、このた
め次の複数個の検出器を用いる方法が一般に行われる。
複数個の既知濃度(CN )溶液を順次被測定溶液用検
出器Xに導き、使用範囲内の上限と下限を含む幾つかの
温度レベル(TS )に対応する伝播時間t'N を測定し、
仮に基準とする検出器SでTS 毎に基準液の伝播時間t
S を測定する。(Measurement method in the case of a plurality of detectors) Switching the reference solution with the same detector is considerably complicated because it is necessary to completely wash the detectors and it takes time, and therefore, the following plural detectors are used. A method using a single detector is generally performed. Leads to a plurality of known concentration (C N) solution successively measured solution detector to X, measuring several propagation time t 'N corresponding to the temperature level (T S) comprising upper and lower limits of the range of use Then
If the detector S is used as a reference, the propagation time t of the reference liquid is increased for each T S.
Measure S.
【0019】検出器Xの伝播路長が検出器Sと全く同
じ特別の場合のt'N をtN 、R'S をRS 、Dt'S をDt
S とすると、RS 、DtS 、CN 、TS 、tS 、tN の
関係式は、検出器が1個の場合と全く同じになる。すな
わち、
ア)検出器の基準液の伝播時間と温度の関係式 tS =F(TS ) (1-1)
イ)RS とTS とCN との関係式 CN =F(RS 、TS ) (1-2)
ウ)DtS とTS とCN との関係式 CN =F(DtS 、TS ) (1-3)
但し、伝播時間比 RS =tN /tS (1-2)'
伝播時間差 DtS =|tS −tN | (1-3)'
R'S :検出器Xでの既知濃度液伝播時間/同温度に於け
る検出器Sでの基準液伝播時間
Dt'S :|検出器Sでの基準液伝播時間−同温度に於け
る検出器Xでの既知濃度液伝播時間|The detector propagation path length of X is in the case of identical special detector S t 'N a t N, R' S a R S, Dt 'S a Dt
When S, relation of R S, Dt S, C N , T S, t S, t N , the detector is exactly the same as the one. That is, a) the relational expression of the propagation time of the reference liquid of the detector and the temperature t S = F (T S ) (1-1) b) the relational expression of R S , T S and C N C N = F (R S , T S ) (1-2) C) Relational expression between Dt S , T S, and C N C N = F (Dt S , T S ) (1-3) However, propagation time ratio R S = t N / T S (1-2) ′ Propagation time difference Dt S = | t S −t N | (1-3) ′ R ′ S : Propagation time of known concentration liquid at detector X / detector S at the same temperature Reference liquid propagation time at Dt ' S : | Reference liquid propagation time at detector S-Propagation time of known concentration liquid at detector X at the same temperature |
【0020】' 被測定用検出器Xの伝播路長が基準液
用検出器Sの伝播路長と等しくない一般的な場合には、
各検出器の伝播路長の比のKを求め、伝播距離に関する
補正係数を導入する。すなわち、ある温度の任意濃度の
液を検出器Sで測定した伝播時間をtS 、伝播経路長が
検出器SのK倍の検出器Xで測定した伝播時間をtXと
し、K=tX /tS からKを求めて (1-2)式または (1-
3)式に適用すると、次のように展開できる。
RS =tN /tS =(1/K)*K*tN /tS =(1/K)*t'N /tS
DtS =|tS −tN |=|tS ー(1/K)*K*tN |=|tS −(1/
K)*t'N |
従って検出器Xの計測値t'N とKから、補正伝播時間比
RS =(1/K)*t'N /tS または補正伝播時間差
DtS =|tS −(1/K)*t'N |を得ることがで
き、濃度測定が可能となる。In the general case where the propagation path length of the measured detector X is not equal to the propagation path length of the reference liquid detector S,
The ratio K of the propagation path lengths of the detectors is obtained, and a correction coefficient for the propagation distance is introduced. That is, let t S be the propagation time measured by the detector S for a liquid of arbitrary concentration at a certain temperature, and let t X be the propagation time measured by the detector X whose propagation path length is K times that of the detector S, and K = t X Find K from / t S and use equation (1-2) or (1-
By applying it to the equation (3), it can be expanded as follows. R S = t N / t S = (1 / K) * K * t N / t S = (1 / K) * t 'N / t S Dt S = | t S -t N | = | t S over (1 / K) * K * t N | = | t S − (1 / K) * t ′ N | Therefore, from the measured values t ′ N and K of the detector X, the corrected propagation time ratio R S = (1 / K) * t 'N / t S or corrected propagation time difference Dt S = | t S - ( 1 / K) * t' N | can be obtained, it is possible to density measurement.
【0021】未知濃度液の濃度測定には、検出器Xで
被測定液の温度TX と伝播時間tXを計測し、同温度に
於ける基準液の伝播時間tS に相当する値を (1-1)式よ
り求め、次にRS =(1/K)*(tX /tS )または
DtS =|tS ー(1/K)*tX |を計算し、 (1-2)
式の時間比方式又は (1-3)式の時間差方式の計算式から
被測定液の濃度を求める。このように検出器Xの伝播路
長が異なっても、Kを使用する事により、同一寸法の検
出器Sを2個使用した場合と全く同じRS 及びDtS の
値を得られることとなり、 (1-2)式または (1-3)式が全
く同じように使用できる。To measure the concentration of the unknown concentration liquid, the temperature X of the liquid to be measured and the propagation time t X are measured by the detector X, and the value corresponding to the propagation time t S of the reference liquid at the same temperature is given by ( 1-1), then R S = (1 / K) * (t X / t S ) or Dt S = | t S- (1 / K) * t X | 2)
Obtain the concentration of the solution to be measured from the time ratio method of formula or the time difference method of formula (1-3). Thus, even if the propagation path lengths of the detectors X are different, by using K, it is possible to obtain exactly the same values of R S and Dt S as when two detectors S of the same size are used. Equation (1-2) or equation (1-3) can be used in exactly the same way.
【0022】なお以上の計測方法において、時間差に基
づく (1-2)' 式、RS =tN /tS=(1/K)*K*
t'N /tS に代えて、正規化補正伝播時間比DRS =±
(1−RS )とし、CN =F(DRS 、TS )を求めて
おいて濃度を求めることができる。この場合(1−
RS )の前の符号は濃度上昇と共にDRS も上昇するよ
うに選ばれる。被測定液が水溶液で基準液として純水を
選定した場合、この方法を行うことによりDRS と濃度
の検量線は原点を通るので、非常に分かり易く単純なも
のとなり、更にデータを加工する場合に特別の工夫が不
要となる。In the above measuring method, the equation (1-2) 'based on the time difference, R S = t N / t S = (1 / K) * K *
Instead of t ′ N / t S , the normalized corrected propagation time ratio DR S = ±
It is possible to obtain the concentration by setting (1−R S ), and obtaining C N = F (DR S , T S ). In this case (1-
The sign before R S ) is chosen such that DR S increases with increasing concentration. If the measured liquid is selected pure water as a reference solution with an aqueous solution, since this method calibration curve DR S and concentration by performing passes through the origin, be very to understand easily simple, yet when processing data No special ingenuity is required.
【0023】(使用開始後の補正方法)超音波伝播速度
から濃度を求める方式の濃度計に於いては、長期使用中
の検出器の伝播路長の変化や計測器の電子回路の長期ド
リフトや経年変化による誤差は一般ユーザーにはなかな
か具体的に把握できず、また補正も簡単には出来ないの
が実状である。このような問題に対して検出器が1個の
場合には、超音波伝播経路長が異なる検出器を使用する
場合と同様の手順で極めて簡単に補正される。すなわち
長期使用後の検出器Xに温度TS の既知濃度液(基準液
でも良い)を導いて測定した伝播時間がtX であり、当
初の検出器Sでの同一条件溶液の測定伝播時間がtS で
あれば、K=tX /tS を算出し、それ以前のKを更新
することにより以後の計測が正常に行われるようにな
る。なおKの変化度合いは検出器を含む測定装置全体の
安定度を示す目安であり、Kを監視することにより整備
・点検の要否が判断できる。なお溶液濃度の測定装置の
狂いを監視する手段として、Kの変化度合いは検出器を
含む測定装置全体の安定度を示す目安でもあり、変化が
一定値以上となった場合に整備・調整を要求する警報機
構を付加することが好ましい。(Correction method after the start of use) In the densitometer of the type that obtains the concentration from the ultrasonic wave propagation velocity, changes in the propagation path length of the detector during long-term use, long-term drift of the electronic circuit of the measuring instrument, and It is difficult for general users to understand the error due to aging, and it is difficult to correct it. For such a problem, when the number of detectors is one, the procedure is the same as that when detectors having different ultrasonic wave propagation path lengths are used, and the correction is extremely simple. That is, the propagation time measured by introducing a liquid of known concentration (which may be the reference liquid) at the temperature T S to the detector X after long-term use is t X , and the measured propagation time of the solution under the same conditions in the detector S at the beginning. If it is t S , K = t X / t S is calculated, and by updating K before that, the subsequent measurement is normally performed. The degree of change in K is a standard indicating the stability of the entire measuring device including the detector, and by monitoring K, the necessity of maintenance and inspection can be determined. As a means of monitoring the deviation of the solution concentration measuring device, the degree of change in K is also a standard for indicating the stability of the entire measuring device including the detector, and maintenance and adjustment are required when the change exceeds a certain value. It is preferable to add an alarm mechanism that operates.
【0024】しかし上記方法による補正は検出器が1個
の場合は、検出器が化学プラントの配管等に直接取付け
られて居ればこの校正は検出器の取外しを伴い、サンプ
ルを導く方式では基準液や被測定液の完全な置換にある
程度の時間を要すること等から、頻繁には行い難い面が
ある。検出器を基準液用と被測定液用とに分ける複数個
の検出器を用いる方法では次のような補正法が行われ、
このような問題点は解消される。However, if the number of detectors is one, the correction by the above method involves the removal of the detector if the detector is directly attached to the piping of the chemical plant, etc. Since it takes a certain amount of time to completely replace the liquid to be measured and the like, it is difficult to carry out frequently. In the method using a plurality of detectors that divide the detector into one for reference liquid and one for measured liquid, the following correction method is performed,
Such a problem is solved.
【0025】すなわち複数個の検出器を用いる方法で使
用後の濃度計補正を行う場合には、基準液用検出器Sを
保管して置き、被測定液用検出器Xの伝播路長の補正も
兼ねた濃度計全体の精度チェック及び校正を行う場合
は、検出器S及び検出器Xに同一温度および濃度の溶液
(測定中の被測定液で良い)を満たし、その時の計測伝
播時間から伝播路長比Kを算出し、それ以前のKを更新
することにより常に正しい計測が可能となる。That is, when the concentration meter after use is corrected by a method using a plurality of detectors, the reference liquid detector S is stored and the propagation path length of the measured liquid detector X is corrected. When performing the accuracy check and calibration of the entire densitometer, which also serves as the densitometer, fill the detector S and the detector X with a solution of the same temperature and concentration (the liquid under measurement may be the measurement target) and propagate from the measurement propagation time at that time. By calculating the road length ratio K and updating K before that, correct measurement is always possible.
【0026】(超音波回路以降の電子回路を複数の検出
器に共通使用の場合の補正方法)上記の方法ではKの更
新時間より短時間の計測回路のドリフトや劣化等による
誤差は解消しきれないが、複数個の検出器を用いる方法
で共通の電子回路を用い、次のように行うことによりこ
の欠点が解消される。すなわち超音波回路以降の電子回
路を複数の検出器に共通に使用し、切替器で複数の検出
器の信号を高速で切替え、各検出器に共通の超音波回路
で比測定溶液と基準液の伝播時間を、温度測定器により
各溶液の温度を共に常時計測し、関係式により濃度測定
すると、計測回路の定常誤差や短期及び長期ドリフト等
による誤差が各伝播時間情報にほぼ等しく現れ、時間差
や時間比に基づく情報処理により、それらの誤差をほと
んど無くすることができる。(Correction method when electronic circuit after ultrasonic circuit is commonly used for a plurality of detectors) In the above method, errors due to drift or deterioration of the measuring circuit shorter than the update time of K can be completely eliminated. Although this is not the case, this drawback is eliminated by using a common electronic circuit in a method using a plurality of detectors and by carrying out the following. That is, the electronic circuit after the ultrasonic circuit is commonly used for a plurality of detectors, the signals of the plurality of detectors are switched at a high speed by a switching device, and the ultrasonic circuit common to each detector is used for the ratio measurement solution and the reference solution. If the temperature of each solution is constantly measured by a temperature measuring device and the concentration is measured by a relational expression, the propagation time will show steady errors in the measurement circuit and errors due to short-term and long-term drifts, etc., appearing approximately in each propagation time information. By the information processing based on the time ratio, those errors can be almost eliminated.
【0027】この場合の式の展開等は基本的には前述の
ものと同じであり、次のような方法が行われる。
被測定液用検出器Xと基準液用検出器Sを、各内部温
度が常時等しくする恒温槽等に設置し、各検出器間の内
部溶液温度に差が無い状態に保つ。
複数個の既知濃度(CN )溶液を順次検出器Xに導
き、使用範囲内の上限と下限を含む幾つかの温度レベル
(TS )に対応する伝播時間t'N を測定し、検出器Sで
該TS 毎に基準液の伝播時間tS を測定する。この時、
切替器で超音波回路と各検出器間の超音波信号を切替
え、超音波回路以降を共通の電子回路を使用すると、ド
リフトの影響が排除され、一層精密な計測ができるThe expansion of the equation in this case is basically the same as that described above, and the following method is performed. The detector X for the liquid to be measured and the detector S for the reference liquid are installed in a constant temperature bath or the like in which the respective internal temperatures are always the same, and the internal solution temperature between the detectors is maintained to be the same. A plurality of solutions of known concentration (C N ) are sequentially introduced to the detector X, the propagation time t ′ N corresponding to several temperature levels (T S ) including the upper limit and the lower limit within the use range is measured, and the detector is detected. At S, the propagation time t S of the reference liquid is measured for each T S. This time,
By switching the ultrasonic signal between the ultrasonic circuit and each detector with the switch and using a common electronic circuit after the ultrasonic circuit, the influence of drift is eliminated and more precise measurement can be performed.
【0028】以下、前述と同じ手順で次の関係式を求
め記憶させる。検出器Xの伝播路長が検出器Sと全く同
じ特別の場合のt'N をtN 、 R'S をRS 、Dt'S をD
tS とする時、RS 、DtS 、CN 、TS 、tS 、tN
の関係式は、
ア)RS 、TS 、CN の関係式 CN =F(RS 、TS ) (1-2)
イ)DtS 、TS 、CN の関係式 CN =F(DtS 、TS ) (1-3)
RS =tN /tS (1-2)'
DtS =|tS ーtN | (1-3)'
但し、R'S :検出器Xでの既知濃度液伝播時間/同温度
に於ける検出器Sでの基準液伝播時間
Dt'S :|検出器Sでの基準液伝播時間−同温度に於け
る検出器Xでの既知濃度液伝播時間|
被測定用検出器Xの伝播路長が基準液用検出器Sの伝播
路長と等しくない一般的な場合は、伝播路長の比のKを
求め、伝播距離に関する補正係数を導入する。
RS =tN /tS =(1/K)*K*tN /tS =(1/K)*t'N /tS
DtS =|tS −tN |=|tS −(1/K)*K*tN |=|tS −(1/
K)*t'N |
従って、検出器Xの計測値t'N とKから、RS またはD
tS を得ることができ濃度測定が可能となる。The following relational expression is obtained and stored in the same procedure as described above. In the special case where the propagation path length of the detector X is exactly the same as that of the detector S, t ′ N is t N , R ′ S is R S , and Dt ′ S is D.
where t S , R S , Dt S , C N , T S , t S , t N
The relational expression of A is a relational expression of R S , T S , and C N C N = F (R S , T S ) (1-2) a) The relational expression of Dt S , T S , and C N C N = F (Dt S , T S ) (1-3) R S = t N / t S (1-2) 'Dt S = | t S -t N | (1-3)' where R 'S : detection Propagation time of known concentration in detector X / reference liquid transit time in detector S at the same temperature Dt ' S : | Reference liquid transit time in detector S-known in detector X at the same temperature Concentration liquid propagation time | In a general case where the propagation path length of the measured detector X is not equal to the propagation path length of the reference liquid detector S, the ratio K of the propagation path lengths is calculated, and the correction coefficient for the propagation distance is calculated. To introduce. R S = t N / t S = (1 / K) * K * t N / t S = (1 / K) * t 'N / t S Dt S = | t S -t N | = | t S - (1 / K) * K * t N | = | t S − (1 / K) * t ′ N | Therefore, from the measured values t ′ N and K of the detector X, R S or D
Since t s can be obtained, the concentration can be measured.
【0029】被測定液用検出器Xと基準液用検出器S
に被測定液と基準液を各々導き、切替器で各検出器と超
音波回路を高速で切り替え、各々、伝播時間と温度を計
測して、関係式より濃度を計算する。すなわち検出器X
で未知濃度溶液の温度TX と伝播時間tX 、同温度に於
ける検出器Sでの基準液の伝播時間tS を計測し、RS
=(1/K)*(tX /tS)または DtS =|tS
−(1/K)*tX |を計算して、上記の (1-2)式また
は (1-3)式に該数値を入れて、濃度が得られる。Detector X for measured liquid and detector S for reference liquid
The liquid to be measured and the reference liquid are respectively guided to each detector, the detector and the ultrasonic circuit are switched at high speed by the switch, the propagation time and the temperature are measured, and the concentration is calculated from the relational expression. Ie detector X
In unknown concentration temperature T X and the propagation time t X solution, the propagation time t S of reference liquid in at detector S in the temperature is measured, R S
= (1 / K) * (t X / t S ) or Dt S = | t S
The concentration is obtained by calculating − (1 / K) * t X | and inserting the numerical value into the above formula (1-2) or formula (1-3).
【0030】各検出器の内部温度が同一でない場合には
次のような方法が行われる。
基準液用検出器Sで適当な温度レベル(TS )毎に基
準液の伝播時間tS を計測し、伝播時間と温度との関係
式 tS =F(TS )〔 (1-1)式〕を作成して記憶させ
る。
被測定溶液の測定温度T1 と基準液の測定温度T2 が
等しくない場合は、RS またはDtS を求める場合のt
S は基準液用検出器での計測伝播時間の代わりに (1-1)
式の温度項にT1 を代入して得られる数値を用い、 (1-
2)式又は (1-2)式により濃度を求める。また測定器が正
常であれば、基準液の測定超音波伝播時間と、tS =F
(TS)にT2 を代入して得られる値との差が零となる
筈であり、溶液濃度の測定装置の狂いを監視する手段と
して、この差またはKの変化が一定以上となった場合に
整備・調整を要求する警報機構を付加することが好まし
い。When the internal temperature of each detector is not the same, the following method is performed. The reference liquid detector S measures the propagation time t S of the reference liquid for each appropriate temperature level (T S ), and the relational expression t S = F (T S ) [(1-1) [Formula] is created and stored. When the measured temperature T 1 of the solution to be measured and the measured temperature T 2 of the reference solution are not equal, t when determining R S or Dt S
S is (1-1) instead of the measurement propagation time at the detector for reference liquid
Using the numerical value obtained by substituting T 1 for the temperature term of the equation, (1-
Obtain the concentration using formula (2) or formula (1-2). If the measuring device is normal, the measurement ultrasonic wave propagation time of the reference liquid and t S = F
The difference from the value obtained by substituting T 2 for (T s ) should be zero, and as a means for monitoring the deviation of the solution concentration measuring device, this difference or the change in K became a certain value or more. In some cases, it is preferable to add an alarm mechanism requesting maintenance and adjustment.
【0031】このように複数個の超音波検出器を用いる
場合には共通の超音波回路とすることにより電子回路に
おけるドリフトおよび定常誤差が著しく低下できる。ま
た一定時間毎、或いは特定指令で上記の超音波伝播路時
間の補正係数を自動的に計算するようにすれば、高精度
の計測が継続して行われるようになる。更に基準液用検
出器と被測定液用検出器を複数用いて、それらに共通の
電子回路で情報処理することにより、1台の分析計で多
点の分析が可能となり、経済的にも優れた分析計とな
る。When a plurality of ultrasonic wave detectors are used in this way, the common ultrasonic wave circuit can significantly reduce the drift and steady-state error in the electronic circuit. Further, if the correction coefficient of the ultrasonic wave propagation path time is automatically calculated at regular time intervals or by a specific command, highly accurate measurement can be continuously performed. Furthermore, by using multiple detectors for the reference liquid and detectors for the measured liquid, and processing information with an electronic circuit common to them, it is possible to perform multipoint analysis with one analyzer, which is economically superior. It becomes an analyzer.
【0032】以上の如き方法で濃度測定を行うために
は、次のような装置が用いられる。
(a)検出器が一個の場合、
超音波を発射する超音波発射素子および超音波受信素子
を有する検出器、該検出器内物質の温度測定器、超音波
伝播時間測定回路、基準液の超音波伝播時間および被測
定液の超音波伝播時間から超音波伝播速度を用いること
なしに被測定液の濃度を計算する手段を有することを特
徴とする溶液濃度の測定装置
(b)複数個の検出器の場合、
超音波を発射する超音波発射素子及び超音波受信素子を
有する被測定液用検出器と基準液用検出器、各検出器の
温度測定器、切替器による各検出器に共通の超音波伝播
時間測定回路、標準液の超音波伝播時間および被測定液
の超音波伝播時間から超音波伝播速度を用いることなし
に被測定液の濃度を計算する手段を有することを特徴と
する溶液濃度の測定装置
また高精度の計測が継続して行われるようにするために
(a)および (b)の装置に、特定時間に被測定液を測定す
る検出器に既知濃度の溶液を満たして超音波伝播時間を
測定し、該関係式を補正する手段が加えられる。In order to measure the concentration by the above method, the following device is used. (a) When there is one detector, a detector having an ultrasonic wave emitting element for emitting ultrasonic waves and an ultrasonic wave receiving element, a temperature measuring device for the substance in the detecting device, an ultrasonic wave propagation time measuring circuit, an ultrasonic wave for the reference liquid. Solution concentration measuring device characterized by having means for calculating the concentration of the liquid to be measured from the ultrasonic wave propagation time and the ultrasonic wave propagation time of the liquid to be measured without using the ultrasonic wave propagation velocity (b) Multiple detection In the case of a detector, a detector for liquid to be measured and a detector for reference liquid having an ultrasonic wave emitting element for emitting ultrasonic waves and an ultrasonic wave receiving element, a temperature measuring device for each detector, and a common detector for each detector Solution characterized by having an ultrasonic wave propagation time measuring circuit, means for calculating the concentration of the solution to be measured from the ultrasonic wave propagation time of the standard solution and the ultrasonic wave propagation time of the solution to be measured without using the ultrasonic wave propagation velocity. Concentration measuring device and high precision measurement In order to be carried out
To the devices (a) and (b), a means for correcting the relational expression by adding a solution having a known concentration to a detector for measuring the liquid to be measured at a specific time, measuring the ultrasonic wave propagation time, is added.
【0033】本発明の超音波を用いて溶液濃度を測定す
る装置(超音波濃度計)は、酸、アルカリ、特定の金属
塩、糖分、有機溶媒、アルコール溶液の濃度測定など多
くの用途に用いられる。溶液中の超音波伝播時間は溶液
温度に大きく依存するので、温度補正を行わずに測定す
る場合は、溶液濃度の測定精度を高めるために検出器内
部溶液の温度を正確に測定して一定に制御する必要があ
る。このための各検出器の温度測定には通常、抵抗温度
計、熱電対温度計、サーミスター温度計などが用いられ
る。The apparatus for measuring the solution concentration using ultrasonic waves of the present invention (ultrasonic densitometer) is used for many purposes such as concentration measurement of acid, alkali, specific metal salt, sugar, organic solvent, alcohol solution. To be Since the ultrasonic wave propagation time in the solution largely depends on the solution temperature, when measuring without temperature compensation, the temperature of the solution inside the detector should be accurately measured and kept constant in order to improve the measurement accuracy of the solution concentration. Need to control. To measure the temperature of each detector for this purpose, a resistance thermometer, a thermocouple thermometer, a thermistor thermometer, etc. are usually used.
【0034】本発明の方法において前述の如く超音波伝
播時間検出器を常に一定温度とすることにより濃度計測
のための関係式を簡略化することができ、また複数個の
検出器を用いる場合において測定精度の更に高い計測を
行うことができる。検出器を常に一定温度とするために
は通常、恒温槽が用いられる。この恒温槽の形状は特に
制限されず、例えば常に一定温度に保たれる配管中に検
出器を設置することもできる。なお検出器が1個の場合
には、被測定液と標準液を同一の温度とするために、恒
温槽内に被測定液と標準液を切替えて通過して検出器に
導入される熱交換器を用いることができる。In the method of the present invention, the relational expression for concentration measurement can be simplified by keeping the ultrasonic wave propagation time detector at a constant temperature as described above, and in the case of using a plurality of detectors. It is possible to perform measurement with higher measurement accuracy. A constant temperature bath is usually used to keep the temperature of the detector constant. The shape of this constant temperature bath is not particularly limited, and for example, the detector can be installed in a pipe that is always kept at a constant temperature. If there is only one detector, heat exchange is introduced into the detector by switching between the measured solution and the standard solution in the constant temperature bath in order to keep the measured solution and the standard solution at the same temperature. Can be used.
【0035】超音波伝播時間の測定は超音波を発射する
超音波発射素子と超音波受信素子を設置した検出器を用
いて行われる。超音波伝播時間を測定する検出器には、
通常、周波数1〜10メガヘルツ程度の超音波発射素子
が用いられる。検出器の信号は超音波伝播時間計測回路
(以下、超音波回路と云う) と交信される。この超音波
回路には、通常、シングアラウンド方式が用いられる。
超音波回路からの電気信号と各検出器の温度測定信号は
演算器に送られ、演算器に記憶された関係式により被測
定液の対象物質の濃度が算出され、必要に応じて濃度表
示器に表示または記録される。The ultrasonic wave propagation time is measured using an ultrasonic wave emitting element for emitting ultrasonic waves and a detector provided with an ultrasonic wave receiving element. The detector that measures the ultrasonic transit time,
Usually, an ultrasonic wave emitting element having a frequency of about 1 to 10 MHz is used. The signal of the detector is an ultrasonic wave propagation time measurement circuit
(Hereinafter referred to as the ultrasonic circuit). A sing-around method is usually used for this ultrasonic circuit.
The electrical signal from the ultrasonic circuit and the temperature measurement signal of each detector are sent to the calculator, and the concentration of the target substance in the liquid to be measured is calculated by the relational expression stored in the calculator, and the concentration indicator is displayed if necessary. Displayed or recorded on.
【0036】複数個の検出器を用いる場合には、その中
の一つを基準液の検出器に用い、被測定液の検出器数は
使用される濃度測定装置の流路数などによって決定され
る。これらの検出器は同一温度に保った方が精度が良
く、計算も簡単なため、共通の恒温槽内に設置すること
が多い。各検出器からの信号は超音波回路と交信して超
音波伝播時間が計測され演算器に送られるが、各検出器
毎に超音波回路を設置すればそれぞれの電子回路のドリ
フトや定常誤差の影響により測定精度が低下することに
なるので、切替器を用いて共通の超音波回路とすること
が望ましい。即ちこの超音波回路は電子回路であるの
で、前述の如くドリフトや定常誤差が避けられず、この
ようなドリフトや定常誤差は各々の回路によって異な
る。基準液及び被測定液の各検出器の超音波回路の信号
を切替器を用いて短時間で切り替えて超音波回路以降を
共通の電子回路で処理することにより、超音波回路以降
のドリフトや定常誤差が前記の超音波伝播時間などに同
程度に現れることから、各検出器の情報と相対処理され
てドリフトや定常誤差の影響が排除され、濃度測定の精
度が著しく向上する。切替器における基準液の検出器か
らの信号と被測定液の検出器からの信号との切替えはタ
イマーにより特定時間毎に行うこともできるし、超音波
回路との同期などの特定指令によって切替えることもで
きる。When a plurality of detectors are used, one of them is used as a detector for the reference liquid, and the number of detectors for the liquid to be measured is determined by the number of flow paths of the concentration measuring device used. It It is more accurate to keep these detectors at the same temperature and the calculation is simple, so they are often installed in a common constant temperature bath. The signal from each detector communicates with the ultrasonic circuit and the ultrasonic propagation time is measured and sent to the computing unit.If an ultrasonic circuit is installed for each detector, the drift and steady-state error of each electronic circuit Since the measurement accuracy will decrease due to the influence, it is desirable to use a common ultrasonic circuit by using a switch. That is, since this ultrasonic circuit is an electronic circuit, drifts and steady errors are unavoidable as described above, and such drifts and steady errors differ depending on each circuit. The signals of the ultrasonic circuit of each detector of the reference liquid and the liquid to be measured are switched in a short time by using a switch and the ultrasonic circuit and subsequent circuits are processed by a common electronic circuit, so that drift and steady state after the ultrasonic circuit can be prevented. Since the error appears in the ultrasonic wave propagation time and the like to the same extent, the influence of drift and steady error is eliminated by performing relative processing with the information of each detector, and the accuracy of concentration measurement is significantly improved. The signal from the detector of the reference liquid and the signal from the detector of the liquid to be measured in the switch can be switched at a specific time by a timer, or by a specific command such as synchronization with the ultrasonic circuit. You can also
【0037】複数の検出器を用いる方法において温度の
影響を大幅に低下させる方法は、各検出器の内部温度
に差が生じないような措置を行い、基準液には通常測
定する濃度に近似した液を使用し、切替器を用いて各
検出器に共通の電子回路でデータ処理を行うことであ
る。これにより基準液に近似した濃度の測定では、後の
実施例に示す如く伝播時間比に基づく方法でも伝播時間
差に基づく方法でも実質的に温度補正が不要となるほど
の効果が得られる。従って測定濃度がほぼ一定の場合に
は、その近似の濃度の液を基準液として選定することが
好ましい。前述の如く恒温槽等を用いて被測定液と標準
液を同一温度とすれば比較的簡単な式で高精度の濃度が
得られるが、被測定液の温度等や外気温度等の影響で検
出器の温度を常に一定の温度に保つことは困難な場合が
多い。溶液中の超音波伝播時間は溶液温度に大きく依存
するので、たとえ恒温槽等を用いる場合でも、伝播時間
比と濃度との関係式に温度ファクターを加えることによ
り溶液濃度の測定精度を高めることができる。In the method of using a plurality of detectors, the method of significantly reducing the influence of temperature is to take measures so as not to make a difference in the internal temperature of each detector, and to make the reference solution close to the concentration usually measured. A liquid is used, and data is processed by an electronic circuit common to each detector using a switching device. As a result, in the measurement of the concentration close to that of the reference liquid, the effect that the temperature correction is substantially unnecessary is obtained by both the method based on the propagation time ratio and the method based on the propagation time difference as will be described in the following examples. Therefore, when the measured concentration is almost constant, it is preferable to select a liquid having an approximate concentration as the reference liquid. As mentioned above, if the temperature of the sample solution and standard solution are kept at the same temperature using a constant temperature bath, etc., a highly accurate concentration can be obtained with a relatively simple formula, but it can be detected by the influence of the temperature of the sample solution or the ambient temperature. It is often difficult to keep the temperature of the vessel constant. Since the ultrasonic wave propagation time in a solution largely depends on the solution temperature, even when using a constant temperature bath, it is possible to improve the measurement accuracy of the solution concentration by adding a temperature factor to the relational expression between the propagation time ratio and the concentration. it can.
【0038】先に濃度計としての精度を高めるために検
出器伝播長さの極く僅かの差異を補正係数Kを用いて補
正することを説明したが、これは基準合わせ(基準液が
0%の時はゼロ調整)も兼ねるものである。補正係数の
校正は、補正指令で指定サンプル弁を切替え、検出器
に同一濃度・温度溶液(基準液または被測定液)を導入
し一定時間後、該サンプル弁を閉止し、各検出器の伝
播時間計測値を記憶し、被測定液用検出器と基準液用検
出器との計測値の比を計算し、以前の補正係数と入替
え、指定サンプル弁を元の状態に切替え、測定状態に
戻すことによって行われる。この補正指令は、特定の指
令スイッチを押しても、シーケンサーのインターバルタ
イマ等により定期的に補正されるようにしても良い。It has been explained above that the slightest difference in the propagation length of the detector is corrected by using the correction coefficient K in order to improve the accuracy of the densitometer. It also serves as a zero adjustment. To calibrate the correction coefficient, switch the designated sample valve with a correction command, introduce a solution of the same concentration and temperature (reference solution or measured solution) into the detector, and after a certain period of time, close the sample valve and propagate each detector. Memorizes the time measurement value, calculates the ratio of the measured values of the measured liquid detector and the reference liquid detector, replaces it with the previous correction coefficient, switches the specified sample valve to the original state, and returns to the measurement state. Done by. This correction command may be corrected periodically by pressing a specific command switch or by a sequencer interval timer or the like.
【0039】次に図面を用いて本発明の装置を説明す
る。図1は一個の検出器を用いた場合における本発明の
溶液濃度測定装置の機器構成図である。図1において基
準液(純水)または被測定液(アルカリ液)が熱交換器
を経て検出器に導入される。基準液と被測定液の切替え
は各流路に設置された電磁弁により行われる。検出器に
は超音波受発射素子と測温体を有し、該受発射素子と超
音波回路間に超音波信号が交信される。またこの熱交換
器および検出器は恒温槽(バスユニット)内に組み込ま
れており、恒温槽に組み込まれた温度調節器により一定
温度に保たれている。超音波回路からの超音波伝播時間
測定信号と検出器温度変換器からの温度信号は演算回路
に送られる。この演算回路の記憶装置には、実施例で示
す如きデータに基づき、濃度測定に必要な演算式や補正
係数Kが記憶されてあり、超音波回路からの伝播時間
情報と検出器温度変換器からの温度情報を入力し、記
憶させた演算式に基づいて濃度計算を行い、表示器に
濃度を表示させると共に、次回の演算結果を得るまで、
この濃度値を保持することを繰返すプログラムにより濃
度測定が実行される。なおこれらの入力、記憶、演算お
よび濃度表示等の機能は全て1台のシーケンサーにより
実行される。Next, the device of the present invention will be described with reference to the drawings. FIG. 1 is a device configuration diagram of a solution concentration measuring device of the present invention when one detector is used. In FIG. 1, the reference liquid (pure water) or the liquid to be measured (alkaline liquid) is introduced into the detector through the heat exchanger. Switching between the reference liquid and the liquid to be measured is performed by a solenoid valve installed in each flow path. The detector has an ultrasonic wave emitting / receiving element and a temperature sensing element, and ultrasonic signals are communicated between the ultrasonic wave receiving / emitting element and the ultrasonic circuit. The heat exchanger and the detector are incorporated in a constant temperature bath (bath unit), and are kept at a constant temperature by a temperature controller incorporated in the constant temperature bath. The ultrasonic propagation time measurement signal from the ultrasonic circuit and the temperature signal from the detector temperature converter are sent to the arithmetic circuit. The storage device of this arithmetic circuit stores an arithmetic expression and a correction coefficient K necessary for the concentration measurement based on the data as shown in the embodiment, and the propagation time information from the ultrasonic circuit and the detector temperature converter are stored. Input the temperature information of, calculate the concentration based on the stored calculation formula, display the concentration on the display, and until the next calculation result is obtained,
Density measurement is performed by a program that repeatedly holds the density value. The functions such as input, storage, calculation and concentration display are all executed by one sequencer.
【0040】図2は複数個(3個) の検出器を用いた場合
における本発明の溶液濃度測定装置の機器構成図であ
る。図2では基準液(純水)の検出器と2基の被測定溶
液(アルカリ液)の検出器が同一の恒温槽(バスユニッ
ト)内に設置されている。各検出器の超音波受発射素子
は切替器経由で共通の超音波回路と結ばれている。該切
替器は手動ポジションと自動ポジションとを持ち、濃度
と伝播時間の基礎データ採取時には手動ポジションと
し、濃度測定時は自動ポジションとしてシーケンサーの
指令により順次切替えが実行される。濃度測定は上記の
図1とほぼ同様に行われ、入力、記憶、演算および濃度
表示等の機能は全て1台のシーケンサーにより実行され
るが、2流路の測定でも各検出器の切替を1秒程度、濃
度データの更新周期は3秒程度の非常に高速で行うこと
ができる。従って図2の如き装置では、各検出器の伝播
時間計測信号が切替器経由で超音波回路以降の電子回路
で共通に処理されることから、各計測信号には電子回路
のドリフトや定常誤差が同じ程度含まれることになり、
各検出器からの計測信号を相対的に処理する伝播時間差
や伝播時間比に基づく濃度計測方法とすることによって
上記誤差が実質的に排除されることになり、高精度の計
測が長時間維持されることになる。FIG. 2 is a device configuration diagram of the solution concentration measuring apparatus of the present invention when a plurality of (three) detectors are used. In FIG. 2, a detector for a standard liquid (pure water) and two detectors for a solution to be measured (alkaline liquid) are installed in the same constant temperature bath (bath unit). The ultrasonic receiving and emitting elements of each detector are connected to a common ultrasonic circuit via a switch. The switch has a manual position and an automatic position. When the basic data of the concentration and the propagation time is collected, the switch is set to the manual position, and when the concentration is measured, the switch is sequentially switched by the command of the sequencer as the automatic position. Concentration measurement is performed almost in the same way as in FIG. 1 above, and functions such as input, storage, calculation, and concentration display are all performed by one sequencer, but switching of each detector is also performed by one sequencer even when measuring two flow paths. The density data can be updated at a very high speed of about 3 seconds, about 3 seconds. Therefore, in the device as shown in FIG. 2, since the propagation time measurement signal of each detector is commonly processed by the electronic circuit after the ultrasonic circuit via the switch, each measurement signal may have drift or steady error of the electronic circuit. Will be included to the same extent,
By using the concentration measurement method based on the propagation time difference and the propagation time ratio that relatively process the measurement signals from each detector, the above error is substantially eliminated, and high-precision measurement is maintained for a long time. Will be.
【0041】[0041]
実施例1
図2に示す濃度測定装置において検出器I には基準液と
して純水を用い、検出器IIには既知濃度の溶液として2.
5wt%、5.0wt%、7.5wt%および10.0wt% のアルカリ溶液を
検出器に満たし、恒温槽を20℃、30℃および40℃にし
て、各検出器に超音波を発射してその伝播時間を測定し
た。検出器の超音波伝播距離は概略140.5mmであり、超
音波回路はシングアラウンド方式である。データ採取時
には超音波回路と各検出器の切替は手動で行った。各温
度における超音波伝播時間の計測結果を表1に示す。こ
の表示はシングアラウンド方式の測定回路からの直読値
(μs)であり、繰り返し回数を4回としたので、実際
の超音波伝播時間の4倍となっている。なお実験中の検
出器I および検出器IIの内部溶液温度差は±0.02℃以内
である。Example 1 In the concentration measuring device shown in FIG. 2, pure water was used as a reference liquid for the detector I and a solution of known concentration was used for the detector II.2.
Fill the detectors with 5wt%, 5.0wt%, 7.5wt% and 10.0wt% alkaline solution, set the constant temperature bath to 20 ℃, 30 ℃ and 40 ℃, emit ultrasonic waves to each detector, and the propagation time Was measured. The ultrasonic propagation distance of the detector is approximately 140.5 mm, and the ultrasonic circuit is a sing-around method. At the time of data collection, the ultrasonic circuit and each detector were switched manually. Table 1 shows the measurement results of the ultrasonic wave propagation time at each temperature. This display is a direct reading value (μs) from the measurement circuit of the sing-around method, and since the number of repetitions is 4, it is four times the actual ultrasonic wave propagation time. The temperature difference between the internal solutions of Detector I and Detector II during the experiment is within ± 0.02 ℃.
【0042】[0042]
【表1】 20℃テスト 30℃テスト 40℃テスト 濃度 検出器I 検出器II 検出器I 検出器II 検出器I 検出器II 0.0 379.03 379.24 372.37 372.58 367.61 367.82 2.5 379.03 369.63 372.37 364.02 367.60 360.06 5.0 379.03 360.18 372.37 355.58 367.60 352.38 7.5 379.03 350.88 372.37 347.23 367.61 344.77 10.0 379.03 341.77 372.36 338.99 367.61 337.22 [Table 1] 20 ℃ test 30 ℃ test 40 ℃ test Concentration Detector I Detector II Detector I Detector II Detector I Detector II 0.0 379.03 379.24 372.37 372.58 367.61 367.82 2.5 379.03 369.63 372.37 364.02 367.60 360.06 5.0 379.03 360.18 372.37 355.58 367.60 352.38 7.5 379.03 350.88 372.37 347.23 367.61 344.77 10.0 379.03 341.77 372.36 338.99 367.61 337.22
【0043】上記の計測値より次の計算を行った結果を
表2〜4及び図3〜図4に示す。
1)超音波伝播速度V(m/s)
検出器IIの計測時間と概略伝播距離(140.5 mm)から超音
波伝播速度V(m/s) を計算した。各温度におけるアルカ
リ濃度と該伝播速度との関係を図3aに示す。このよう
に超音波伝播速度から溶液濃度を求める方法は従来の方
法である。The results of the following calculations based on the above measured values are shown in Tables 2 to 4 and FIGS. 1) Ultrasonic propagation velocity V (m / s) The ultrasonic propagation velocity V (m / s) was calculated from the measurement time of the detector II and the approximate propagation distance (140.5 mm). The relationship between the alkali concentration at each temperature and the propagation speed is shown in FIG. 3a. Thus, the method of obtaining the solution concentration from the ultrasonic wave propagation velocity is a conventional method.
【0044】2)伝播時間差 ( DTa = ts -tN )
検出器IIにおいて基準液を純水とした場合の計測伝播時
間 t0 と、各濃度における計測伝播時間 tN との伝播時
間差 ( DTa = ts -tN ) を計算し、各温度におけるアル
カリ濃度と伝播時間差の関係を図3bに示す。これは本
発明の方法により1個の検出器において伝播時間差より
溶液濃度を求める場合であり、溶液濃度はこのように伝
播時間差と温度から一義的に決定され、この方法により
伝播距離の測定誤差による影響が解消されるので高精度
の測定が行われる。2) Propagation time difference (DTa = t s -t N ) Propagation time difference (DTa) between the measured propagation time t 0 when the reference liquid is pure water in the detector II and the measured propagation time t N at each concentration. = t s -t N ), and the relationship between alkali concentration and propagation time difference at each temperature is shown in FIG. 3b. This is a case where the solution concentration is obtained from the propagation time difference in one detector by the method of the present invention, and the solution concentration is uniquely determined from the propagation time difference and the temperature as described above, and this method causes a measurement error of the propagation distance. Since the influence is eliminated, highly accurate measurement is performed.
【0045】3)補正伝播時間差百分率
検出器IIと検出器I の双方に基準液を満たした場合の各
検出器の伝播時間比を伝播距離補正係数Kとし、検出器
I の計測時間 ts から検出器IIの各濃度毎の計測伝播時
間 tN に1/Kを掛けた数値を引いた伝播時間差〔DTb =t
s -(1/K)* tN〕を計算し、20℃,10.0%時の DTbを 100%
としたときの各温度におけるアルカリ濃度と該補正伝
播時間差の百分率との関係を図3cに示す。この関係図
は超音波伝播長の異なる検出器を用いる場合や使用開始
後の検出器の補正に用いられ、補正すべき検出器のKを
求めることにより該関係図を共通に使用することができ
る。3) Corrected Propagation Time Difference Percentage The propagation time ratio of each detector when both detector II and detector I are filled with the reference liquid is designated as a propagation distance correction coefficient K, and
Propagation time difference obtained by subtracting the value obtained by multiplying the measured propagation time t N for each concentration of the detector II by 1 / K from the measurement time t s of I [DTb = t
s- (1 / K) * t N ] is calculated, and DTb at 20 ° C, 10.0% is 100%.
3c shows the relationship between the alkali concentration at each temperature and the percentage of the corrected propagation time difference. This relational diagram is used when detectors with different ultrasonic wave propagation lengths are used or for correction of the detectors after the start of use, and the relational diagram can be commonly used by obtaining K of the detector to be corrected. .
【0046】4)伝播時間比( Ra = tN /ts )
検出器IIにおける基準液濃度 (純水100.0wt%) の計測伝
播時間 ts と、各濃度における計測伝播時間 tN との該
伝播時間比( Ra = tN /ts ) を計算した。各温度におけ
るアルカリ濃度と伝播時間比の関係を図4aに示す。こ
れは一個の検出器において伝播時間比から溶液濃度を求
める場合の関係図であり、溶液濃度はこのように伝播時
間比と温度からも一義的に決定され、伝播距離の測定誤
差による影響が解消されるので高精度の測定が行われ
る。4) Propagation time ratio (Ra = t N / t s ) The measured propagation time t s of the reference liquid concentration (pure water 100.0 wt%) in the detector II and the measured propagation time t N at each concentration The propagation time ratio (Ra = t N / t s ) was calculated. The relationship between the alkali concentration and the propagation time ratio at each temperature is shown in FIG. 4a. This is a relational diagram when the solution concentration is calculated from the propagation time ratio in one detector, and the solution concentration is uniquely determined from the propagation time ratio and temperature in this way, and the influence of the measurement error of the propagation distance is eliminated. Therefore, highly accurate measurement is performed.
【0047】5)伝播時間比( Rb = tN /ts )
検出器IIにおける各濃度における計測伝播時間 tN と検
出器I おける基準液濃度 (純水100.0wt%) の計測伝播時
間 ts との該伝播時間比( Rb = tN /ts ) を計算した。
各温度におけるアルカリ濃度と該伝播時間比の関係を図
4bに示す。これは複数個の検出器で伝播時間比より溶
液濃度を求める場合であり、複数個の検出器では使用開
始後の検出器の補正が容易であり、切替器を用いて超音
波回路以降を共通化することにより高精度の測定が容易
に行うことができる。5) Propagation time ratio (Rb = t N / t s ) Measured propagation time t N at each concentration in detector II and measured propagation time t s of reference liquid concentration (deionized water 100.0 wt%) in detector I And the propagation time ratio (Rb = t N / t s ) of
The relationship between the alkali concentration at each temperature and the propagation time ratio is shown in FIG. 4b. This is a case where the solution concentration is calculated from the propagation time ratio with multiple detectors, and it is easy to correct the detectors after using them with multiple detectors, and the ultrasonic circuit and subsequent ones can be shared by using a switching device. Highly accurate measurement can be easily performed.
【0048】6)正規化補正伝播時間比〔 DRs= 1− (1/
K)*(tN /ts ) 〕
検出器IIにおける各濃度における計測伝播時間 tN と検
出器I おける基準液濃度 (純水100.0wt%) の計測伝播時
間 ts の伝播時間比を計算し、伝播距離補正係数Kで補
正して正規化した正規化補正伝播時間比〔DRs=1− (1/
K)*(tN /ts )〕を求め、各温度におけるアルカリ濃度
と正規化補正伝播時間比の関係を図4cに示す。これは
複数個の検出器において正規化された補正伝播時間比よ
り溶液濃度を求める場合であり、この関係図は超音波伝
播長の異なる検出器を用いる場合や使用開始後の検出器
の補正に用いられ、補正すべき検出器のKを求めること
により該関係図を共通に使用することができ、またこの
方法を行うことによりDRs と濃度の検量線は原点を通る
ので、非常に分かり易く単純なものとなり、更にデータ
を加工する場合に特別の工夫が不要となる。6) Normalized corrected propagation time ratio [DRs = 1- (1 /
K) * (t N / t s )]] Calculate the propagation time ratio of the measured propagation time t N at each concentration in the detector II and the measured propagation time t s of the reference liquid concentration (deionized water 100.0 wt%) in the detector I. Then, the normalized corrected propagation time ratio [DRs = 1- (1 /
K) * (t N / t s )], and the relationship between the alkali concentration and the normalized correction propagation time ratio at each temperature is shown in FIG. 4c. This is the case where the solution concentration is calculated from the normalized corrected propagation time ratio for multiple detectors.This relationship diagram is for the case of using detectors with different ultrasonic wave propagation lengths and for correcting the detectors after the start of use. The relationship diagram can be used in common by obtaining the K of the detector to be corrected, and by performing this method, the DRs and concentration calibration curves pass through the origin, so it is very easy to understand and simple. In addition, no special device is required when further processing the data.
【0049】[0049]
【表2】 (実施例1、20℃テスト) 濃度 伝播速度V 時間差DTa DTb DT% 時間比Ra Rb DRs 0.0 1481.9 0.00 0.00 0.00 1.00000 1.00055 0.00000 2.5 1520.4 9.61 9.60 25.63 0.97466 0.97520 0.02534 5.0 1560.3 19.06 19.05 50.87 0.94974 0.95027 0.05026 7.5 1601.7 28.36 28.34 75.67 0.92522 0.92573 0.07478 10.0 1644.4 37.47 37.45 100.0 0.90120 0.90170 0.09880 [Table 2] (Example 1, 20 ° C. test) Concentration Propagation velocity V Time difference DTa DTb DT% Time ratio Ra Rb DRs 0.0 1481.9 0.00 0.00 0.00 1.00000 1.00055 0.00000 2.5 1520.4 9.61 9.60 25.63 0.97466 0.97520 0.02534 5.0 1560.3 19.06 19.05 50.87 0.94974 0.95027 0.05026 7.5 1601.7 28.36 28.34 75.67 0.92522 0.92573 0.07478 10.0 1644.4 37.47 37.45 100.0 0.90120 0.90170 0.09880
【0050】[0050]
【表3】 (実施例1、30℃テスト) 濃度 伝播速度V 時間差DTa DTb DT% 時間比Ra Rb DRs 0.0 1508.4 0.00 0.00 0.00 1.00000 1.00056 0.00000 2.5 1543.9 8.56 8.56 22.86 0.97703 0.97758 0.02297 5.0 1580.5 17.00 16.99 45.37 0.95437 0.95491 0.04563 7.5 1618.5 25.35 25.34 67.66 0.93196 0.93249 0.06804 10.0 1657.9 33.59 33.56 89.61 0.90984 0.91038 0.09013 [Table 3] (Example 1, 30 ° C. test) Concentration Propagation velocity V Time difference DTa DTb DT% Time ratio Ra Rb DRs 0.0 1508.4 0.00 0.00 0.00 1.00000 1.00056 0.00000 2.5 1543.9 8.56 8.56 22.86 0.97703 0.97758 0.02297 5.0 1580.5 17.00 16.99 45.37 0.95437 0.95491 0.04563 7.5 1618.5 25.35 25.34 67.66 0.93196 0.93249 0.06804 10.0 1657.9 33.59 33.56 89.61 0.90984 0.91038 0.09013
【0051】[0051]
【表4】 (実施例1、40℃テスト) 濃度 伝播速度V 時間差DTa DTb DT% 時間比Ra Rb DRs 0.0 1527.9 0.00 0.00 0.00 1.00000 1.00057 0.00000 2.5 1560.9 7.76 7.75 20.03 0.97890 0.97949 0.02107 5.0 1594.9 15.44 15.42 41.17 0.95802 0.95860 0.04195 7.5 1630.1 23.05 23.04 61.52 0.93733 0.93787 0.06267 10.0 1666.6 30.60 30.58 81.66 0.91681 0.91733 0.08319 [Table 4] (Example 1, 40 ° C. test) Concentration Propagation velocity V Time difference DTa DTb DT% Time ratio Ra Rb DRs 0.0 1527.9 0.00 0.00 0.00 1.00000 1.00057 0.00000 2.5 1560.9 7.76 7.75 20.03 0.97890 0.97949 0.02107 5.0 1594.9 15.44 15.42 41.17 0.95802 0.95860 0.04195 7.5 1630.1 23.05 23.04 61.52 0.93733 0.93787 0.06267 10.0 1666.6 30.60 30.58 81.66 0.91681 0.91733 0.08319
【0052】以上の実験データに基づき作成された温度
補正の項を含んだ関係式の一例を次に示す。
CN =F(DRs,T)=75.7477*DRs+1.14268*DRs*T-2.2576
7*10-3*DRs*T2+33.4798*DRs2 +0.155824* DRs2 *T-8.62
56*10-3*DRs2 *T2
この演算式に DRsと Tを代入して得られる濃度 (演算濃
度) と、実験に用いた濃度 (実験濃度) との関係を表5
に示す。これより非常に精度の高い関係式が得られてい
ることが分かる。An example of the relational expression including the term of temperature correction created based on the above experimental data is shown below. C N = F (DRs, T) = 75.7477 * DRs + 1.14268 * DRs * T-2.2576
7 * 10 -3 * DRs * T 2 + 33.4798 * DRs 2 + 0.155824 * DRs 2 * T-8.62
56 * 10 -3 * DRs 2 * T 2 Table 5 shows the relationship between the concentration obtained by substituting DRs and T in this equation (calculated concentration) and the concentration used in the experiment (experimental concentration).
Shown in. It can be seen that a highly accurate relational expression is obtained from this.
【0053】[0053]
【表5】 実験濃度 (20℃テスト) (30℃テスト) (30℃テスト) (wt%) DRs 演算濃度 DRs 演算濃度 DRs 演算濃度 0.0 0.00000 0.00 0.00000 0.00 0.00000 0.00 2.5 0.02534 2.50 0.02297 2.50 0.02107 2.49 5.0 0.05026 4.99 0.04563 4.99 0.04195 4.99 7.5 0.07478 7.49 0.06804 7.49 0.06267 7.49 10.0 0.09880 9.98 0.09013 9.98 0.08319 9.98[Table 5] Experimental concentration (20 ℃ test) (30 ℃ test) (30 ℃ test) (wt%) DRs calculated concentration DRs calculated concentration DRs calculated concentration 0.0 0.00000 0.00 0.00000 0.00 0.00000 0.00 2.5 0.02534 2.50 0.02297 2.50 0.02107 2.49 5.0 0.05026 4.99 0.04563 4.99 0.04195 4.99 7.5 0.07478 7.49 0.06804 7.49 0.06267 7.49 10.0 0.09880 9.98 0.09013 9.98 0.08319 9.98
【0054】実施例2
実施例1と同様の濃度測定装置において検出器I には既
知濃度の溶液として0.0wt%、1.0wt%、2.0wt%、2.38wt%
、3.00wt% 、4.0wt%および5.0wt%のアルカリ溶液を検
出器に満たし、検出器III には常に 2.38wt%のアルカリ
溶液を基準液として満たし、恒温槽を10℃、20℃、35℃
および50℃として、各検出器に超音波を発射してその伝
播時間を測定した。この時間はシングアラウンド方式の
測定回路からの直読値(μs)であり、繰り返し回数を
4回としたので、実際の超音波伝播時間の4倍となって
いる。また次の計算を行い、その結果を表6〜9に示
す。Example 2 In the same concentration measuring apparatus as in Example 1, the detector I was used as a solution having a known concentration of 0.0 wt%, 1.0 wt%, 2.0 wt% and 2.38 wt%.
, 3.00wt%, 4.0wt% and 5.0wt% alkaline solution is filled in the detector, and detector III is always filled with 2.38wt% alkaline solution as the standard solution, and the thermostat is kept at 10 ℃, 20 ℃, 35 ℃.
And 50 ° C., ultrasonic waves were emitted to each detector and the propagation time was measured. This time is a direct reading value (μs) from the measurement circuit of the sing-around method, and since the number of repetitions is 4, it is four times the actual ultrasonic wave propagation time. Further, the following calculation was performed, and the results are shown in Tables 6-9.
【0055】1)補正伝播時間差〔 DTb = ts -(1/K)* t
N 〕
検出器I と検出器III の双方に基準液 (濃度2.38wt%)を
満たした場合の各検出器の計測時間比を伝播距離補正係
数Kとし、検出器III の計測時間 ts から検出器I の各
濃度毎の計測時間 tN にKを掛けた数値を引いた差の伝
播時間差〔 DTb= ts -(1/K)* tN 〕を計算した。各温
度におけるアルカリ濃度と該補正伝播時間差の関係を図
5aに示す。これは複数個の検出器で基準液に被測定液
と近似した濃度の液を用い補正伝播時間差から溶液濃度
を求める場合であり、特に基準液に近似した濃度の被測
定液では温度の影響が少なく、非常に高精度の濃度測定
が行われる。[0055] 1) correction propagation time difference [DTb = t s - (1 / K) * t
N ] The detection time ratio of each detector when both the detector I and the detector III are filled with the reference liquid (concentration 2.38 wt%) is set as the propagation distance correction coefficient K, and detected from the measurement time t s of the detector III. instrumental propagation time difference of a difference obtained by subtracting the numerical value obtained by multiplying the K to the measured time t N for each concentration of I - a [DTb = t s (1 / K ) * t N ] were calculated. The relationship between the alkali concentration at each temperature and the corrected propagation time difference is shown in FIG. 5a. This is a case in which a solution with a concentration similar to that of the measured liquid is used as the reference liquid with multiple detectors, and the solution concentration is obtained from the corrected propagation time difference. Very few and highly accurate concentration measurements are made.
【0056】2)伝播時間比( Rb = tN /ts )
検出器I における各濃度における計測時間 tN と検出器
III おける基準液濃度(濃度2.38wt%)の計測時間 ts と
の伝播時間比を計算した。これは複数個の検出器で標準
液に被測定液と近似した濃度の液を用い、伝播時間比よ
り溶液濃度を求める場合であり、切替器を用いて超音波
回路以降を共通化することにより高精度の測定が容易に
行うことができ、また特に基準液に近似した濃度の被測
定液では非常に高精度の濃度測定が行われる。2) Propagation time ratio (Rb = t N / t s ) Measurement time t N at each concentration in the detector I and the detector
The propagation time ratio of the reference liquid concentration (concentration 2.38 wt%) in III to the measurement time t s was calculated. This is a case where a solution with a concentration similar to the measured solution is used as the standard solution with multiple detectors, and the solution concentration is obtained from the propagation time ratio. High-accuracy measurement can be easily carried out, and particularly in the case of the liquid to be measured having a concentration close to that of the reference liquid, very high-precision concentration measurement can be carried out.
【0057】3)補正伝播時間比〔Rc = (1/K)*(tN /
ts ) 〕
検出器I における各濃度における計測時間 tN と検出器
III おける基準液濃度(濃度2.38wt%)の計測時間 ts と
の伝播時間比を計算し、伝播距離補正係数Kで補正した
〔Rc = (1/K)*(tN /ts ) 〕。各温度におけるアルカリ
濃度と該補正伝播時間比の関係を図5bに示す。これは
複数個の検出器で標準液に被測定液と近似した濃度の液
を用い、補正伝播時間比より溶液濃度を求める場合であ
り、この関係図は超音波伝播長の異なる検出器を用いる
場合や使用開始後の検出器の補正に用いられ、補正すべ
き検出器のKを求めることにより該関係図を共通に使用
することができる。3) Corrected propagation time ratio [Rc = (1 / K) * (t N /
t s )] Measurement time t N at each concentration in detector I and detector
The propagation time ratio of the reference solution concentration (concentration 2.38 wt%) in III to the measurement time t s was calculated and corrected with the propagation distance correction coefficient K [Rc = (1 / K) * (t N / t s )]. . The relationship between the alkali concentration at each temperature and the corrected propagation time ratio is shown in FIG. 5b. This is a case where a solution with a concentration similar to the solution to be measured is used as the standard solution with multiple detectors, and the solution concentration is determined from the corrected propagation time ratio.This relationship diagram uses detectors with different ultrasonic wave propagation lengths. In the case or after the start of use, it is used for the correction of the detector, and the relationship diagram can be commonly used by obtaining the K of the detector to be corrected.
【0058】3)正規化補正伝播時間比 (DRs = 1.0 −Rc
)
各温度におけるアルカリ濃度と DRsの関係を図5Cに示
す。各検出器におけるKを求め DRsを計算すれば、この
関係図は共通のものとして溶液濃度を高精度に得ること
ができる。3) Normalized corrected propagation time ratio (DRs = 1.0-Rc
) Figure 5C shows the relationship between the alkali concentration and DRs at each temperature. If K is calculated for each detector and DRs is calculated, it is possible to obtain the solution concentration with high accuracy by making this relationship diagram common.
【0059】[0059]
【表6】 (実施例2、10℃テスト) 濃度 伝播時間I 伝播時間III 時間差DTb 時間比Rb 時間比Rc DRs 0.0 382.77 374.26 -10.43 1.02274 1.02787 -0.02787 1.0 378.36 374.27 -5.99 1.01093 1.01600 -0.01600 2.0 374.04 374.28 -1.64 0.99936 1.00438 -0.00438 2.38 372.45 374.32 0.00 0.99500 1.00000 0.00000 3.0 369.80 374.37 2.71 0.98779 0.99275 0.00725 4.0 365.61 374.46 7.01 0.97637 0.98127 0.01873 5.0 361.27 374.32 11.24 0.96514 0.96998 0.03002[Table 6] (Example 2, 10 ° C. test) Concentration Propagation time I Propagation time III Time difference DTb Time ratio Rb Time ratio Rc DRs 0.0 382.77 374.26 -10.43 1.02274 1.02787 -0.02787 1.0 378.36 374.27 -5.99 1.01093 1.01600 -0.01600 2.0 374.04 374.28 -1.64 0.99936 1.00438 -0.00438 2.38 372.45 374.32 0.00 0.99500 1.00000 0.00000 3.0 369.80 374.37 2.71 0.98779 0.99275 0.00725 4.0 365.61 374.46 7.01 0.97637 0.98127 0.01873 5.0 361.27 374.32 11.24 0.96514 0.96998 0.03002
【0060】[0060]
【表7】 (実施例2、20℃テスト) 濃度 伝播時間I 伝播時間III 時間差DTb 時間比Rb 時間比Rc DRs 0.0 373.70 366.51 -9.06 1.01962 1.02473 -0.02473 1.0 369.97 366.61 -5.22 1.00917 1.01423 -0.01423 2.0 366.18 366.60 -1.42 0.99885 1.00387 -0.00387 2.38 364.78 366.61 0.00 0.99501 1.00000 0.00000 3.0 362.41 366.61 2.38 0.98854 0.99350 0.00650 4.0 358.71 366.61 6.10 0.97845 0.98336 0.01664 5.0 355.02 366.65 9.85 0.96828 0.97314 0.02686[Table 7] (Example 2, 20 ° C. test) Concentration Propagation time I Propagation time III Time difference DTb Time ratio Rb Time ratio Rc DRs 0.0 373.70 366.51 -9.06 1.01962 1.02473 -0.02473 1.0 369.97 366.61 -5.22 1.00917 1.01423 -0.01423 2.0 366.18 366.60 -1.42 0.99885 1.00387 -0.00387 2.38 364.78 366.61 0.00 0.99501 1.00000 0.00000 3.0 362.41 366.61 2.38 0.98854 0.99350 0.00650 4.0 358.71 366.61 6.10 0.97845 0.98336 0.01664 5.0 355.02 366.65 9.85 0.96828 0.97314 0.02686
【0061】[0061]
【表8】 (実施例2、35℃テスト) 濃度 伝播時間I 伝播時間III 時間差DTb 時間比Rb 時間比Rc DRs 0.0 364.78 358.92 -7.69 1.01633 1.02142 -0.02142 1.0 361.52 358.90 -4.43 1.00730 1.01235 -0.01235 2.0 358.34 358.92 -1.22 0.99838 1.00339 -0.00339 2.38 357.13 358.92 0.00 0.99501 1.00000 0.00000 3.0 355.17 358.96 2.01 0.98944 0.99440 0.00560 4.0 352.01 358.98 5.21 0.98058 0.98550 0.01450 5.0 348.89 359.03 8.39 0.97176 0.97663 0.02337[Table 8] (Example 2, 35 ° C. test) Concentration Propagation time I Propagation time III Time difference DTb Time ratio Rb Time ratio Rc DRs 0.0 364.78 358.92 -7.69 1.01633 1.02142 -0.02142 1.0 361.52 358.90 -4.43 1.00730 1.01235 -0.01235 2.0 358.34 358.92 -1.22 0.99838 1.00339 -0.00339 2.38 357.13 358.92 0.00 0.99501 1.00000 0.00000 3.0 355.17 358.96 2.01 0.98944 0.99440 0.00560 4.0 352.01 358.98 5.21 0.98058 0.98550 0.01450 5.0 348.89 359.03 8.39 0.97176 0.97663 0.02337
【0062】[0062]
【表9】 (実施例2、50℃テスト) 濃度 伝播時間I 伝播時間III 時間差DTb 時間比Rb 時間比Rc DRs 0.0 359.40 354.45 -6.75 1.01397 1.01905 -0.01905 1.0 356.55 354.44 -3.90 1.00595 1.01100 -0.01100 2.0 353.73 354.44 -1.07 0.99800 1.00301 -0.00301 2.38 352.67 354.44 0.00 0.99501 1.00000 0.00000 3.0 350.92 354.44 1.76 0.99007 0.99504 0.00496 4.0 348.12 354.44 4.57 0.98217 0.98710 0.01290 5.0 345.32 354.44 7.39 0.97427 0.97916 0.02084[Table 9] (Example 2, 50 ° C. test) Concentration Propagation time I Propagation time III Time difference DTb Time ratio Rb Time ratio Rc DRs 0.0 359.40 354.45 -6.75 1.01397 1.01905 -0.01905 1.0 356.55 354.44 -3.90 1.00595 1.01100 -0.01100 2.0 353.73 354.44 -1.07 0.99800 1.00301 -0.00301 2.38 352.67 354.44 0.00 0.99501 1.00000 0.00000 3.0 350.92 354.44 1.76 0.99007 0.99504 0.00496 4.0 348.12 354.44 4.57 0.98217 0.98710 0.01290 5.0 345.32 354.44 7.39 0.97427 0.97916 0.02084
【0063】以上の実験データに基づき作成された温度
補正の項を含んだ関係式の一例を次に示す。
CN =F(DRs,T)=76.5041*DRs+1.02363*DRs*T-0.0008
97496*DRs* T2-7.71778*DRs2 -1.04891*DRs2 *T+0.0175
716*DRs2 *T2 +2.38
この演算式に DRsと Tを代入して得られる濃度 (演算濃
度) と、実験に用いた濃度 (実験濃度) との関係を表1
0に示す。この例でも非常に精度の高い関係式が得られ
ていることが分かる。An example of the relational expression including the term of temperature correction created based on the above experimental data is shown below. C N = F (DRs, T) = 76.5041 * DRs + 1.02363 * DRs * T-0.0008
97496 * DRs * T 2 -7.71778 * DRs 2 -1.04891 * DRs 2 * T + 0.0175
716 * DRs 2 * T 2 +2.38 Table 1 shows the relationship between the concentration obtained by substituting DRs and T in this equation (calculated concentration) and the concentration used in the experiment (experimental concentration).
It shows in 0. It can be seen that a highly accurate relational expression is also obtained in this example.
【0064】[0064]
【表10】 実験濃度 (20℃テスト) (35℃テスト) (50℃テスト) (wt%) DRs 演算濃度 DRs 演算濃度 DRs 演算濃度 0.0 -0.02473 -0.02 -0.02142 -0.01 -0.01905 -0.02 1.0 -0.01423 1.00 -0.01235 1.00 -0.01100 1.00 2.0 -0.00387 2.01 -0.03393 2.00 -0.00301 2.00 2.38 0.00000 2.38 0.00000 2.38 0.00000 2.38 3.0 0.00650 3.01 0.00560 3.00 0.00496 3.00 4.0 0.01664 3.98 0.01450 3.99 0.01290 4.00 5.0 0.02686 4.96 0.02337 4.97 0.02084 4.99[Table 10] Experimental concentration (20 ℃ test) (35 ℃ test) (50 ℃ test) (wt%) DRs calculated concentration DRs calculated concentration DRs calculated concentration 0.0 -0.02473 -0.02 -0.02142 -0.01 -0.01905 -0.02 1.0 -0.01423 1.00 -0.01235 1.00 -0.01100 1.00 2.0 -0.00387 2.01 -0.03393 2.00 -0.00301 2.00 2.38 0.00000 2.38 0.00000 2.38 0.00000 2.38 3.0 0.00650 3.01 0.00560 3.00 0.00496 3.00 4.0 0.01664 3.98 0.01450 3.99 0.01290 4.00 5.0 0.02686 4.96 0.02337 4.97 0.02084 4.99
【0065】[0065]
【発明の効果】本発明による溶液濃度の測定方法および
その装置では、超音波速度を用いずに伝播時間を用いて
測定されるので、超音波伝播距離の変化やその測定誤差
による影響が解消されて非常に高精度の濃度が得られ
る。また標準液と被測定液の検出器を別に設置する場合
には切替器により超音波回路以降を共通とすることなど
によって、電子回路におけるドリフトや定常誤差が共通
化されて、高精度の濃度測定が行われる。従って本発明
により、従来の滴定分析計に匹敵する高精度の濃度測定
値が得られる。更に本発明による溶液濃度測定装置は市
販の一般的な電子回路等で構成されるものであり、自動
制御装置などにおいて極めて有利に用いられ、本発明の
工業的意義が大きい。In the solution concentration measuring method and apparatus according to the present invention, the propagation time is measured without using the ultrasonic velocity, so that the influence of the change of the ultrasonic propagation distance and the measurement error thereof can be eliminated. And very accurate concentration can be obtained. Also, when the detectors for standard solution and measured solution are separately installed, the ultrasonic circuit and the subsequent circuits can be shared by a switch, so that drift and steady-state error in the electronic circuit can be shared and highly accurate concentration measurement can be performed. Is done. Thus, the present invention provides highly accurate concentration measurements comparable to conventional titration analyzers. Furthermore, the solution concentration measuring device according to the present invention is constituted by a commercially available general electronic circuit or the like, and is extremely advantageously used in an automatic control device or the like, and the industrial significance of the present invention is great.
【図1】本発明による一個の超音波検出器で被測定液お
よび標準液を共通に用いる場合の濃度測定装置の機器の
構成を示す図である。FIG. 1 is a diagram showing a device configuration of a concentration measuring device when a solution to be measured and a standard solution are commonly used in one ultrasonic detector according to the present invention.
【図2】本発明による2個の被測定液の検出器と標準液
の検出器の場合の濃度測定装置の機器の構成を示す図で
ある。FIG. 2 is a diagram showing a device configuration of a concentration measuring device in the case of two detectors for a liquid to be measured and a detector for a standard liquid according to the present invention.
【図3】実施例1におけるデータより超音波伝播速度、
伝播時間差 ( DTa = ts -tN )および補正伝播時間差〔
DTb = ts -(1/K)* tN 〕とアルカリ濃度との関係を示
す図面である。FIG. 3 shows the ultrasonic wave propagation velocity from the data in Example 1,
Propagation time difference (DTa = t s -t N ) and corrected propagation time difference (
DTb = t s - a (1 / K) * t N] and the drawings showing the relationship between the alkali concentration.
【図4】実施例1において検出器を一個及び複数個用い
る場合の伝播時間比( Ra = tN/ts ) および正規化補正
伝播時間比〔DRs = 1− (1/K)*(tN /ts ) 〕とアルカ
リ濃度との関係を示す図面である。FIG. 4 is a propagation time ratio (Ra = t N / t s ) and a normalized correction propagation time ratio [DRs = 1- (1 / K) * (t N / t s )] and the alkali concentration.
【図5】実施例2における補正伝播時間差〔 DTb =(ts
-(1/K)* tN ) 〕、補正伝播時間比〔Rc =(1/ K)*(tN
/ts ) 〕および正規化補正伝播時間比 (DRs = 1.0 −R
c)とアルカリ濃度との関係を示す図面である。FIG. 5: Corrected propagation time difference [DTb = (t s
-(1 / K) * t N )], corrected propagation time ratio [Rc = (1 / K) * (t N
/ t s )] and the normalized corrected propagation time ratio (DRs = 1.0 −R
It is a drawing which shows the relationship between c) and alkali concentration.
Claims (13)
個の既知濃度の溶液および基準液の超音波伝播時間を測
定して関係式を作成し、該関係式から被測定液の濃度を
求めるに際し、該関係式に伝播路長に関連する補正項を
有し、且つ該補正項が(1)基準とする検出器を用いて
測定して得られた任意の液の超音波伝播時間情報、およ
び(2)補正対象の検出器で測定して得られた(1)と
同液の超音波伝播時間情報からなることを特徴とする溶
液濃度の測定方法。1. An ultrasonic wave propagation time detector for a solution measures ultrasonic wave propagation times of a plurality of solutions having a known concentration and a reference solution to create a relational expression, and obtains the concentration of a solution to be measured from the relational expression. upon, have a correction term related to the propagation path length to the equation, and using a detector to which the correction term is to (1) the reference
The ultrasonic propagation time information of any liquid obtained by measurement, and
(2) and (1) obtained by measuring with the detector to be corrected
A method for measuring a solution concentration, which comprises ultrasonic wave propagation time information of the same solution .
音波伝播時間と温度を測定して関係式を作成する請求項
1に記載の溶液濃度の測定方法。2. The solution concentration measuring method according to claim 1, wherein the ultrasonic wave propagation time and temperature of a plurality of solutions having a known concentration and a reference solution are measured to create a relational expression.
時間を測定して得られた超音波伝播時間情報の比(時間
比)または補正された時間比を前記関係式に用いる請求
項1または2に記載の溶液濃度の測定方法。3. Ultrasonic propagation of a solution having a known concentration and a reference solution.
The method for measuring a solution concentration according to claim 1, wherein a ratio ( time ratio ) of ultrasonic wave propagation time information obtained by measuring time or a corrected time ratio is used in the relational expression.
時間を測定して得られた超音波伝播時間情報の差(時間
差)または補正された時間差を前記関係式に用いる請求
項1または2に記載の溶液濃度の測定方法。4. Ultrasonic propagation of a solution having a known concentration and a reference solution.
The solution concentration measuring method according to claim 1 or 2, wherein a difference ( time difference ) in ultrasonic wave propagation time information obtained by measuring time or a corrected time difference is used in the relational expression.
基準液の超音波伝播時間を測定し、該関係式により被測
定液の濃度を求める請求項1〜4の何れかに記載の溶液
濃度の測定方法。5. The ultrasonic wave propagation time of a plurality of solutions having known concentrations and a reference solution is measured by one detector, and the concentration of the solution to be measured is determined by the relational expression. Method for measuring solution concentration.
で複数個の既知濃度の溶液の超音波伝播時間を測定し、
基準液用検出器で基準液の超音波伝播時間を測定し、該
関係式により被測定液の濃度を求める請求項1〜4の何
れかに記載の溶液濃度の測定方法。6. An ultrasonic wave propagation time of a plurality of solutions having known concentrations is measured by a detector for a liquid to be measured, using a plurality of detectors.
5. The solution concentration measuring method according to claim 1, wherein the ultrasonic wave propagation time of the reference liquid is measured with a reference liquid detector, and the concentration of the liquid to be measured is determined by the relational expression.
る請求項6の溶液濃度の測定方法。7. The method for measuring a solution concentration according to claim 6, wherein a common ultrasonic circuit is used for a plurality of detectors.
液を検出器に通過して超音波伝播時間を測定し、該関係
式を補正する請求項1〜7の何れか一項に記載の溶液濃
度の測定方法。8. The method according to claim 1, wherein a solution having a known concentration is passed through a detector at a specific time or a specific command to measure an ultrasonic wave propagation time, and the relational expression is corrected. Solution concentration measurement method.
音波受信素子を有する検出器、該検出器内物質の温度測
定器、超音波伝播時間測定回路を有し、且つ複数個の既
知濃度の溶液および基準液の超音波伝播時間を測定し、
(1)基準とする検出器を用いて測定して得られた任意
の液の超音波伝播時間情報、および(2)補正対象の検
出器で測定して得られた(1)と同液の超音波伝播時間
情報からなる、伝播路長に関連する補正項を有する関係
式を用いて被測定液の濃度を計算する手段を有すること
を特徴とする溶液濃度の測定装置。9. A detector having an ultrasonic wave emitting element for emitting ultrasonic waves and an ultrasonic wave receiving element, a temperature measuring device for the substance in the detector, an ultrasonic wave propagation time measuring circuit , and a plurality of known concentrations. The ultrasonic wave propagation time of the solution and reference solution of
(1) Arbitrary values obtained by measurement using a detector as a reference
Information of ultrasonic wave propagation time of liquid, and (2) detection of correction target
Ultrasonic wave propagation time of the same liquid as (1) obtained by measuring with a dispenser
An apparatus for measuring a solution concentration, comprising means for calculating the concentration of a liquid to be measured using a relational expression having a correction term related to a propagation path length, which comprises information.
音波受信素子を有する被測定液用検出器と基準液用検出
器、各検出器の温度測定器、切替器による各検出器に共
通の超音波伝播時間測定回路を有し、且つ複数個の既知
濃度の溶液および基準液の超音波伝播時間を測定し、
(1)基準とする検出器を用いて測定して得られた任意
の液の超音波伝播時間情報、および(2)補正対象の検
出器で測定して得られた(1)と同液の超音波伝播時間
情報からなる、伝播路長に関連する補正項を有する関係
式を用いて被測定液の濃度を計算する手段を有すること
を特徴とする溶液濃度の測定装置。10. A detector for liquid to be measured and a detector for reference liquid having an ultrasonic wave emitting element for emitting an ultrasonic wave and an ultrasonic wave receiving element, a temperature measuring device for each detector, and a common detector for each detector. Having an ultrasonic wave propagation time measurement circuit , and measuring the ultrasonic wave propagation time of a plurality of solutions of known concentration and reference solution,
(1) Arbitrary values obtained by measurement using a detector as a reference
Information of ultrasonic wave propagation time of liquid, and (2) detection of correction target
Ultrasonic wave propagation time of the same liquid as (1) obtained by measuring with a dispenser
An apparatus for measuring a solution concentration, comprising means for calculating the concentration of a liquid to be measured using a relational expression having a correction term related to a propagation path length, which comprises information.
に既知濃度の溶液を満たして超音波伝播時間および温度
を測定し、該関係式を補正する手段を有する請求項9又
は10に記載の溶液濃度の測定装置。11. The method according to claim 9 or 10, further comprising means for filling a detector for measuring the liquid to be measured with a solution having a known concentration at a specific time, measuring the ultrasonic wave propagation time and temperature, and correcting the relational expression. The solution concentration measuring device described.
式を作成し、基準液の温度情報から得られる超音波伝播
時間と、測定して得られる該時間との差または比から、
溶液濃度の測定装置の狂いを監視する手段を有する請求
項9〜11の何れかに記載の溶液濃度の測定装置。12. An ultrasonic wave propagation time of the reference liquid is measured to create a relational expression, and from the difference or ratio between the ultrasonic wave propagation time obtained from the temperature information of the reference liquid and the time obtained by measurement,
The solution concentration measuring device according to any one of claims 9 to 11, further comprising means for monitoring a deviation of the solution concentration measuring device.
して関係式を作成し、該溶液の超音波伝播時間情報と温
度情報の時間的経過から、溶液濃度の測定装置の狂いを
監視する手段を有する請求項12に記載の溶液濃度の測
定装置。13. An ultrasonic wave propagation time of a solution having a known concentration is measured to create a relational expression, and the deviation of the solution concentration measuring device is monitored from the time course of ultrasonic wave propagation time information and temperature information of the solution. The solution concentration measuring device according to claim 12, further comprising:
Priority Applications (1)
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JP30650194A JP3381747B2 (en) | 1994-12-09 | 1994-12-09 | Method and apparatus for measuring solution concentration |
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JP30650194A JP3381747B2 (en) | 1994-12-09 | 1994-12-09 | Method and apparatus for measuring solution concentration |
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Publication Number | Publication Date |
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JPH08159946A JPH08159946A (en) | 1996-06-21 |
JP3381747B2 true JP3381747B2 (en) | 2003-03-04 |
Family
ID=17957790
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JP30650194A Expired - Fee Related JP3381747B2 (en) | 1994-12-09 | 1994-12-09 | Method and apparatus for measuring solution concentration |
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JP (1) | JP3381747B2 (en) |
Families Citing this family (10)
Publication number | Priority date | Publication date | Assignee | Title |
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JP2002071646A (en) * | 2000-08-28 | 2002-03-12 | Kyoto Electron Mfg Co Ltd | Liquid concentration measuring method |
JP2003185537A (en) * | 2001-12-20 | 2003-07-03 | Fujitsu Ltd | Measuring apparatus for chemical liquid, chemical liquid- supplying method, and measuring method for concentration of chemical liquid |
JP4540375B2 (en) * | 2004-03-24 | 2010-09-08 | 株式会社ミヤコシ | Ink density measurement method |
JP5608884B2 (en) * | 2009-05-09 | 2014-10-22 | 本多電子株式会社 | Ultrasonic flow meter and fluid supply system |
JP5956834B2 (en) * | 2012-06-04 | 2016-07-27 | 日本無線株式会社 | Processing equipment |
CN104122170A (en) * | 2013-04-25 | 2014-10-29 | 上海朝辉压力仪器有限公司 | Liquid density instrument |
JP6481999B2 (en) * | 2015-03-09 | 2019-03-13 | 日本無線株式会社 | Surface acoustic wave sensor and solution property measuring method |
JP6961306B2 (en) * | 2017-11-10 | 2021-11-05 | 株式会社ディスコ | Inspector, liquid supply device, and protective film coating device |
DE102018202587A1 (en) * | 2018-02-21 | 2019-08-22 | Robert Bosch Gmbh | Device for determining quality, tank device |
WO2022074820A1 (en) * | 2020-10-09 | 2022-04-14 | 三菱重工業株式会社 | Analysis system and management system, analysis method, and analysis program |
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1994
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