1.1 ,This test method covers determining the activity and coke selectivity of either equilibrium or laboratory deactivated fluid catalytic cracking (FCC) catalysts. The activity is evaluated on the basis of mass percent conversion of gas oil feed in a fluidized bed reactor. The coke yield is defined as the mass of carbon laid down on the catalyst, also expressed as a percent of the gas oil feed. The scope of the round robin will be limited to the determination of activity and coke. All other analyses are thus beyond this scope and should be noted as “,optional.”,