Detection Principle of Trace Moisture Tester
Micro-moisture tester computer automatic control technology, using a large screen LCD display, full Chinese menu prompts the operation of a wealth of arithmetic, print the results of the experiment function, is the petroleum, chemical, electric power, medicine, pesticide industry and scientific research colleges and universities to test the moisture content of the heart of the instrument. Karl Fischer method, referred to as Fischer method, is the 1935 Karl Fischer (Karl Fischer) proposed the determination of moisture capacity split method. Fischer's method is the determination of material moisture in all types of chemical methods, water is more specific, the most accurate method.
The classical method has been improved in recent years to increase the accuracy and extend the measuring range, and has been listed as a standard method for the determination of moisture in many substances. Fischer-Tropsch method is an iodine quantity method, the basic principle is the use of iodine oxidation of sulphur dioxide, the need for -quantity of water to participate in the reaction: I2SO22H2O-2HIH2SO4 The above reaction is reversible. When the * concentration reaches 0.05% or more, the reverse reaction can occur. If we allow the reaction to proceed in a positive direction, we need to add a suitable alkaline substance to neutralise the acid produced during the reaction. It has been experimentally proven that pyridine is added to the system so that the reaction proceeds in the right direction.
It is especially suitable for samples that are easily destroyed by heat, and can measure not only free water but also bound water, and is often used as a standard method for analysing water, especially trace water. However, it is not suitable for samples containing strong reducing substances such as VC. Karl Fischer reagent is a kind of reagent for the determination of trace water in some substances, and its components are: methanol, pyridine, iodine, sulphur dioxide. The endpoint determination methods are visual and potentiometric.
