DANSK DSF/ISO/FDIS 18787 PDF

This International Standard gives basic principles and requirements for the methods of determining water activity (aw) of food products for human consumption and animal feed within a measurement range of 0 to 1. The measurement principles are based on the dew-point measurement or on the determination of the change in electrical conductivity of an electrolyte or in the permittivity of a polymer. The method does not apply to products stored below their freezing point (equivalent to the temperature at which ice crystals appear in the product) or to products corresponding to a water-in-fat emulsion or to crystal products such as sugars, salt, minerals. For products containing volatile compounds, such as alcohols, specific equipment adaptations may be necessary to apply the method.