This standard determines the carboxyl group content in wood or lint pulp, reflecting the surface charge of the pulp, which is an important indicator in the paper industry. The standard includes two test methods: sodium chloride - carbonic acid method and methylene blue method, which are suitable for different carboxyl group ranges and conditions. The sodium chloride - carbonic acid method has lower Accuracy in the low carboxyl group value range, while the methylene blue method is suitable for the entire carboxyl group value range, but not for soluble carbohydrate materials. Users of the standard need to pay attention to safety and regulatory requirements.