ISO 11289:1993 (R2021)

The principle of the method specified is preparing the test sample according to the class to which the product to be examined belongs, and measuring the potential difference between a glass electrode and a reference electrode immersed in the test sample. Applies to four classes of product: 1. homogeneous products with a liquid or thick texture, or products exhibiting a large liquid or thick phase; 2. homogeneous pastes or heterogeneous products for which homogenization is necessary; 3. heterogeneous products with large solid components; 4. products whose liquid phase mainly consists of oil or a water/oil emulsion.