Moisture content/water content (residual moisture)
The choice of the appropriate method depends essentially on the expected moisture content. Higher water contents can be determined gravimetrically well with the drying oven technique. When lower water contents are expected, the water selective Karl Fischer titration should be chosen, as incorrect measurements, for example by other volatile matters can be excluded. The Karl Fischer method is, however, not intended for determination of higher water contents.
Standard Tests
Moisture of paper/board
Specific Norm: DIN EN ISO 15512
The test is performed by gravimetry according to the traditional oven drying method. This is not selective for water, other volatiles are also detected. The method is therefore only suitable for higher water contents and samples with a negligible amount of other volatiles besides water. The samples, as desired, are tested as received (without condioning) or after conditioning in a standard climate 23/50 or a climate according to your information. The moisture retention of the samples are usually in the lower percentage range.
Moisture content of plastics (e.g. granulates, plastic films, cold sealants)
Specific Norm: DIN EN ISO 15512 Verfahren B2
The test is carried out with the water-selective Karl Fischer method. Solid samples, e.g. plastic resins or plastic films, are heated prior to the measurement in a furnace and the extracted gas phase is led for analysis in the Karl Fischer solution. This method is particularly suitable for low absolute levels well below one percent down to a few ppm, So for example, also of determining the residual moisture in thin coatings (e.g., dispersions) on moisture-free carrier films (e.g. of polyethylene).
Moisture content of, liquid samples, e.g. solvents, printing inks, laquers
Specific Norm: DIN 51777-1
The test is carried out with the water-selective Karl Fischer method. In the case of liquid samples, e.g. Solvent, these could be analyzed directly. This method is particularly suitable for low absolute levels well below one percent down to a few ppm.
Moisture content, substrate with coating
Specific Norm: DIN EN ISO 15512
This method can be used, for example, to determine the moisture content of acrylate dispersions on polyethylene films.