This International Standard specifies a method for determination of water up to 25 % in petroleum products, bitumens, tars and products derived from these materials, excluding emulsions, by the distillation method. The specific products considered during the development of this test method are listed in Table 3. This International Standard may be used to determine water content in excess of 25 %. However, no precision data has been determined at levels greater than 25 %. Volatile water-soluble material, if present, is measured as water. NOTE 1 A knowledge of the water content of petroleum products is important in the refining, purchase, sale and transfer of products. NOTE 2 The amount of water determined by this method can be used to correct the volume involved in the custody transfer of product.