Unlike the gravimetric moisture-measuring techniques, the result is not distorted by substances evaporating from the sample. It therefore delivers reproducible, accurate results and facilitates separate identification of free surface and capillary water, as well as bonded water.
The water is evaporated out of the sample in a programmable oven and is fed to the sensor by a carrier gas. The coulometric sensor absorbs water into its hygroscopic phosphorous pentoxide coating. The water is electrolysed immediately and the required electrical charge is proportional to the quantity of water which is determined. Thus the sensor regenerates itself and is always ready to use.
Operation is extremely simple. No special or toxic chemicals are required to operate the system. The operator profits by reduced operating and disposal costs, as well as reduced blank value input regarding chemicals.