1.1 ,This test method covers the procedure for distillation of heavy hydrocarbon mixtures having initial boiling points greater than 150 ,°,C (300 ,°,F), such as heavy crude oils, petroleum distillates, residues, and synthetic mixtures. It employs a potstill with a low pressure drop entrainment separator operated under total takeoff conditions. Distillation conditions and equipment performance criteria are specified and typical apparatus is illustrated.