GB 6856-1986 stipulates the relevant standards for the pH reference reagent sodium tetraBoricacid. Clarify its technical requirements, such as key indicators such as purity and impurity limit, standardize inspection rules, including sampling plans and judgment basis. At the same time, rigorous test methods are given to determine various indicators. The production and inspection of sodium tetraBoricacid according to this standard can ensure its high accuracy and reliability as a reference reagent in the field of pH measurement. In chemical analysis, scientific research experiments, water quality testing and many other scenarios that rely on accurate pH value determination, it provides a solid foundation for accurate quantity traceability and guarantees the accuracy of related work.