The principle of the method specified is passing a measured volume of gas through the titration cell, where the water is absorbed by the anodic solution. The iodine required for the determination of water by the Karl Fischer reaction is generated coulometrically from iodide. The quantity of electricity is directly proportional to the mass of iodine generated and hence to the mass of water determined. Applies to natural gas and other gases which do not react with Karl Fischer reagents. Is applicable to water concentrations between 5 mg/ cm^3 and 5000 mg/ cm^3.