This International Standard specifies a method for the determination of ash in the pitch for electrodes used in the production of aluminium. The method is applicable to products (tar pitch, petroleum pitch, etc.) producing a quantity of ash greater than or equal to 0,05 % (m/m). If it is required to express the result on the dry product, carry out the water determination by azeotropic distillation as specified in ISO 5939. Refer the result of the determination of ash obtained on the product as such, to the dry product. NOTE — This ash may be utilised for subsequent elemental analysis.