The ISO 9202 standard specifies the method for determining the fineness of jewelry and precious metal alloys. The standard applies to jewelry, precious metals and their alloys, helping to determine the composition ratio and mass level of precious metal alloys. By precise measurement of the precious metal content in the alloy, ensure that the product meets the relevant mass and industry requirements. The standard provides a scientific basis for quality control for the jewelry industry and promotes conformity and transparency in the production, trading and certification of jewelry and precious metal alloys. This method is widely used in jewelry manufacturers, testing agencies and precious metal suppliers, providing an important standard for the accurate assessment of precious metal alloys.