Chemical concentration measurement and control equipment

Flow injection method

Measurement by Tokai Senko’s original continuous titration method

VOICE

About the processing liquid concentration of the factory line (process). Since it operates continuously, the change in processing liquid concentration is large. Therefore, I always want to control the concentration. However, the chemical solution is a mixture of multiple chemicals and cannot be measured with a measuring device. Therefore, since it can be measured only by titration, it is only titrated once every few hours. I want to constantly monitor as if measuring with a sensor.

Since it is a continuous titration method, it is possible to monitor the measured concentration.
In general titration, the concentration is measured intermittently, but since this device continuously samples, preprocesses, and titrates, it is possible to detect the concentration change quickly. It is also possible to measure the concentration of multiple chemicals at the same time, depending on the type of chemicals to be mixed.

The titration work is very time-consuming. The person in charge collects the chemical solution from the factory and measures it in the laboratory. I want to collect concentration data once an hour for process control, but I can only measure it once a day because it takes a lot of manpower. I want to measure frequently and always manage.

This device fully automates complicated tasks from sample collection to pretreatment and concentration measurement. We will strive for continuous process management and labor saving. In addition, the results can be saved on a memory card so that you can check the measurement history on your computer.

Currently we are measuring the concentration by titration. When the concentration decreases, the person in charge supplies chemicals and adjusts the concentration. I want to control the concentration automatically because the person in charge frequently puts in chemicals.

CCC METER II can even control the concentration. In addition to stabilizing the concentration, there are cases where the amount of chemicals used has decreased.

Feature

●It can be measured with accuracy comparable to manual analysis.
●Since it is constantly measured, it is possible to continuously monitor it, which is not possible with normal titration.
●This device automatically performs all complicated work from sampling to preprocessing and measurement.

●Fully automated. You can continuously manage various processes and save labor.
●The measurement results can be fed back to various processes. It is also possible to control the concentration.
●You can manage the measurement data on your computer.

measurement principle

CCC METER II is a measuring machine that continues titration analysis. In manual analysis, the equivalence point is detected by the change in the color of the indicator, but in this machine, the ORP electrode and pH electrode are used.

Measurement example: In the case of hydrogen peroxide （H₂O₂）

When hydrogen peroxide（H₂O₂）is titrated, the ORP potential (oxidation-reduction potential) changes as shown in Fig. 1 as the reagent (potassium permanganate （KMnO₄））) is added. The ORP potential rises as the reagent is dropped. Especially when approaching the equivalence point, the ORP potential changes rapidly. In the case of hydrogen peroxide, it changes significantly around 750 mV.

CCC METER II uses this principle to measure the hydrogen peroxide concentration by the flow injection method.

※What is the flow injection analysis method?

Flow injection is a method of (1) continuously flowing a sample into a thin tube, (2) injecting a reagent into it and causing a chemical reaction, and (3) measuring the ORP potential and analyzing the concentration.

As shown in Fig. 2, a certain amount of sample（H₂O₂）is passed through a system in which a constant amount of diluted water is poured. Add sulfuric acid（H₂SO₄）and reagent （KMnO₄）to the solution and measure the ORP potential. The amount of sample liquid（H₂O₂）supplied is constant, but the concentration (processing liquid concentration) is constantly changing. Therefore, the amount of reagent is controlled so that it always reaches the equivalence point (750 mV). For example, when it is 750 mV or less, the amount of reagent is increased, and when it is 750 mV or more, the amount of reagent is decreased. CCC METER II grasps the amount of this reagent and converts it to the concentration of hydrogen peroxide.

Example

(1) The solution in the “processing tank” is circulated by the circulation pump (“circulation pump”-> “processing tank”-> “adjustment tank”).
(2) During circulation, a part of the solution is sampled to “CCC METER II”.
(3) Measure the concentration of the sampled processing liquid by continuous titration.
(4) If the measured concentration is lower than the set concentration, feed it back and adjust the concentration with the “concentration adjustment pump”.
(5) Perform steps (1) to (4) continuously.
The above is an example of the system. Designed to your specifications.