Karl Fischer Operations
The Karl Fischer operates by the coulometric titration method, which occurs at the anode. The negatively charged ions flow to the anode, which reacts with the iodine present in the Coulometric C solution. The electrical charge is measured. When all the water has been titrated, the excess iodine is detected by an electrometric endpoint (measured in mA). Based on the stoichiometry one mole of iodine reacts with mole of water, thus the water content is equal to the total current produced.
Importance of the Karl Fischer Test
The Karl Fischer test is important because it informs the user how much water is in his system. High water can cause coalescing filter and bearing damage. It also causes corrosion in the compressor.