规定方法的原理是根据待检产品所属类别制备试样，并测量浸入试样中的玻璃电极和参比电极之间的电位差。适用于四类产品:1。具有液体或厚质地的均质产品，或具有大液体或厚相的产品；2.均质膏体或需要均质的非均质产品；3.固体成分大的非均质产品；4.液相主要由油或水/油乳液组成的产品。

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.