Karl Fischer Titrator is used for Accurate Moisture Estimation in various samples. The Karl Fischer method is used for many substances as a reference method. It is a chemical analysis procedure which is based on the oxidation of sulfur dioxide by iodine in alcoholic solution. The titration can be performed Volumetrically or Coulometrically.
In the Volumetric Method, Karl Fischer solution containing iodine is added until the first trace of excess iodine is present. The volume of K. F. Reagent is proportional to the water content in the sample. It is necessary to standardize the Karl Fischer Reagent using known water standards such as Distilled Water or Sodium Tartrate Dihydrate (DST).
Volumetric Titrator is used for higher water contents such as 100 PPM and above using appropriate sample quantity. For higher water contents, less sample quantity is necessary and proportionately higher sample quantity is required for low water contents.
In the Coulometric Method, the iodine required in the reaction is generated in the titration cell by electrochemical oxidation of iodide until again a trace of un-reacted iodine is detected. Using Faraday's law, the amount of iodine generated to neutralize the water content is calculated from the quantity of electricity required.
The Coulometric Titrator is used for trace analysis of water content. This model is recommended for Transformer/Insulating Oils containing water less than 100 PPM.