This is a method standard for the testing of key raw materials in the natural rubber industry. It specifies in detail how to determine the alkalinity of concentrated natural latex (i.e., its ammonia or potassium hydroxide content). The standard provides two methods: potentiometric titration and visual (colorimetric) titration. The potentiometric titration method uses a precise pH meter (with an accuracy of 0.02 pH units) combined with an automatic potentiometric titrator to monitor the endpoint, ensuring result accuracy. Regarding core testing instruments, in addition to the titration setup, the standard explicitly requires the use of an electric stirrer with non-metallic paddles (or a magnetic stirrer) to maintain sample uniformity, as well as an analytical balance with a precision of 0.01 grams. Its latest version further unifies and optimizes the testing procedures, providing a reliable basis for the production, trade, and quality control of natural latex.