This standard specifies a method for the determination of ash content of all solid biofuels. The ash content is determined by calculation from the mass of the residue remaining after the sample is heated in air under rigidly controlled conditions of time, sample weight and equipment specifications to a controlled temperature of (550 ± 10) °C. Automatic equipment may be used for the determination when the method is validated with biomass reference samples of an adequate biomass type and this equipment fulfils certain specified requirements. The standard has been prepared by CEN/TC 335 "Solid biofuels", the secretariat of which is held by SIS (Sweden). The responsible German committee is Working Committee NA 062-05-82 AA "Feste Biobrennstoffe" ("Solid biofuels") at NMP.