Metrohm has developed a method to determine the moisture content of gases based on the ISO standard 10101.
The reproducible determination of the water content is tricky as many gases usually only contain a few ug/L water.
The problem is not the coulometric measurement itself, but the sample introduction.
An optimal measuring set up and the exact determination of the gas volume are the be-all and end-all of water determination in the lower ppm range.
In order to ensure a reproducible gas introduction time, the control of the valves should be automated.
The Tiamo titration software is suitable for this purpose.
By using a relay box, the valves can be opened and closed according to the conditioning or determination status of the coulometer.
In addition, the duration of the gas introduction is documented and can be used for calculating the gas volume.
The gas to be analysed is passed through the Karl Fischer titration cell in which the water is absorbed by the KF reagent and then determined using Metrohm's 831 KF coulometer.
In addition to natural gas, the Metrohm method can also be used for other gases that do not react with the Karl Fischer reagent.
