Volumetric Karl Fischer Moisture Titrator
Karl Fischer Moisture Analysis uses two techniques. For very small amounts of moisture, the Coulometric Technique is preferred. When moisture content gets above the 1% to 2% range the Volumetric Technique is warranted.
The basis of the Karl Fischer technique is a reaction between iodine and water. This reaction changes the the conductivity of a sample containing water to a different level after the Karl Fischer reaction. This change in conductivity determines the end point of the reaction.
With this volumetric technique a solvent is placed in a sealed container or titration cell that includes an electrode, a sample port, a port for the introduction of Karl Fischer Reagent and a stirrer. Check the left column for a schematic of a typical system.
The testing procedure starts with the introduction of the sample, which is dissolved in a solvent contained in the titration cell. This changes the electrical conductivity of the solvent/sample mix.
Through the use of an automatic burette, reagent is added and reacts with the water to return the conductivity to the starting point. The amount of water/moisture in the sample is calculated based on the amount of reagent need to reach this point.
We offer the Hanna 903 Karl Fischer Titrator for this process. This instrument conducts the test automatically. It has a range of moisture content from 100 parts per million to 100%.
In addition to an on-board display, USB connectivity permits direct input from an electronic balance and results transfer to a computer.
Detailed specifications of the Hanna 903 are available in the Volumetric Karl Fischer section of the CSC On-Line Store. Click on the button below: