This standard specifies a method for the determination of the ash content of petroleum products such as distillate and residual fuel oils, crude petroleum, lubricating oils, waxes and other petroleum products, in which any ash-forming constituents present are normally considered to be undesirable impurities or contaminants. Ash can result from oil-soluble or water-soluble metallic compounds or from extraneous solids such as dirt and rust. The method is applicable to products having ash contents in the range 0,001 % (m/m) to 0,180 % (m/m), but does not apply to products which contain ash-forming additives, including certain phosphorus compounds. The analysis