A method for determining the partial acid value (method A) and the total acid value (method B) of polyester resins and binders for paints and varnishes are defined in this standard. It is not applicable to phenolic resins. The intention of the standard is to provide quality-control data for the acceptance or rejection of such products in accordance with the terms defined, as well as to be used in research and development to monitor the completion of the polycondensation reaction.