The iodine needed for the reaction is replenished by adding iodine-containing standard solution.
This instrument belongs to the coulometric method, which is based on the fact that after the sample is dissolved in the electrolyte of a special solvent containing a certain amount of iodine, the water consumes iodine, and the required iodine is no longer titrated with standard iodine-containing reagents, but through the electrolysis process , so that the iodide ions in the solution are oxidized to iodine at the anode:
2I———2e——→I2……………………………………………………(2)
The iodine produced reacts with the water in the sample again, and the end point is indicated by a double platinum electrode. When the iodine concentration in the electrolyte returns to the original concentration, stop the electrolysis. Then according to Faraday's law of electrolysis:
m=×=
In the formula: m——the weight of water in the sample, mg;
C——electricity consumed by electrolysis, mc;
M - the molecular weight of water;
n - electron transfer number;
i——electrolysis current, mA;
t——electrolysis time, s;
96500——Faraday's constant;
10722——Electrolysis of 1mg of water consumes electricity, mc.
As long as the required parameters are input into the microcomputer of the instrument, the water content in the analysis sample can be expressed in ppm or %, μg.
Trace moisture analyzer is a new generation of intelligent moisture analyzer combined with micro-coulomb principle and single-chip microcomputer technology. It has the characteristics of high sensitivity, fast analysis speed, accurate results, and easy operation. It is widely used in petroleum, Fertilizer, chemical industry, electric power, metallurgy, medicine, geology, college teaching and other fields. Executive standard: SH/T0246.
Features
1. It has high sensitivity, fast analysis speed, accurate results and easy operation. Both high-low water content can be accurately measured.
2. The trace moisture analyzer is a new generation of intelligent moisture analyzer based on the principle of microcoulomb titration, using double platinum electrodes to detect the titration process, and using a microcomputer to control the electrolysis and data processing systems.
3. The instrument can automatically perform baseline correction. The operating parameters and analysis results are not only displayed by the LCD module, but also can be printed and archived by the printer as required. The instrument has the advantages of high sensitivity, good stability, accurate results, simple operation and fast analysis. The instrument can be used for the analysis of water content in petroleum and petrochemical products, and can also be used for monitoring the water content of substances in the production and scientific research of chemical, food, electric power, metallurgy, medicine, sanitation and environmental protection systems.
