API gravity measures the density of petroleum liquids.

API gravity measures the density of petroleum liquids.

• A. Viscosity
• B. Density of petroleum liquids
• C. Temperature
• D. Pressure

Answer: (B)

API gravity is a density-based measure for petroleum liquids, expressed relative to water. The higher the API gravity, the lighter the liquid; the lower the API gravity, the heavier the liquid. This relationship comes from how API gravity is defined in terms of the liquid’s specific gravity at 60°F. In practice, API gravity directly reflects how dense a hydrocarbon is, which is why crude oils and fuels are categorized by API numbers to compare heaviness or lightness. Because API gravity is tied to density (specific gravity), it does not measure viscosity, temperature, or pressure. Those properties are separate factors used for other aspects of cargo handling and safety. For context, an API gravity around 40 is very light (density well below water), while an API gravity around 10 is much heavier (density near or slightly above water).

API gravity is a density-based measure for petroleum liquids, expressed relative to water. The higher the API gravity, the lighter the liquid; the lower the API gravity, the heavier the liquid. This relationship comes from how API gravity is defined in terms of the liquid’s specific gravity at 60°F. In practice, API gravity directly reflects how dense a hydrocarbon is, which is why crude oils and fuels are categorized by API numbers to compare heaviness or lightness.

Because API gravity is tied to density (specific gravity), it does not measure viscosity, temperature, or pressure. Those properties are separate factors used for other aspects of cargo handling and safety. For context, an API gravity around 40 is very light (density well below water), while an API gravity around 10 is much heavier (density near or slightly above water).