This standard specifies a dedicated method for determining the pH value of polyvinyl alcohol (PVAL) materials, with the key focus on preparing the test solution for measurement. The standard details the process of dissolving PVAL samples in heated deionized or distilled water under specific conditions, followed by cooling to room temperature to form the solution to be tested. Subsequently, the measurement is performed using a calibrated laboratory pH meter equipped with a glass electrode-reference electrode pair or a combination pH electrode. This method excludes the direct measurement of powdered PVAL, ensuring that the results reflect the actual acid-base characteristics of the material in aqueous solution, which is crucial for controlling the performance of PVAL in applications such as adhesives and textile sizing agents.