This standard specifies the technical requirements for standard water used in the physical testing of pulp, applicable to various pulp-related experimental scenarios. Its core objective is to mitigate the impact of electrolytes and impurities on pulp drainage performance and brightness (whiteness) by limiting the water's electrical conductivity. It stipulates that the electrical conductivity of standard water at 25°C shall not exceed 0.25 mS/m. The standard covers the entire process of preparation, testing, storage, and usage. Water can be prepared using methods such as distillation or ion exchange, and testing requires a conductivity meter (equipped with temperature compensation and a measurement accuracy of ±1%) as well as common laboratory glassware. Additionally, it specifies that storage must be carried out in airtight containers made of inert materials to prevent water quality deterioration, thereby providing critical assurance for the accuracy and consistency of physical test results for pulp.