Hydrometers are glass instruments that are calibrated and are normally used to compare the densities of liquids. They can be used to measure the specific gravity or relative density of a material.

Petroleum hydrometers, also known as API hydrometers are used to determine density, relative density, API gravity or specific gravity of crude petroleum, petroleum products or mixture of petroleum and non petroleum products, which are normally handled as liquids.

Working Principle of Petroleum Hydrometer

• Generally, values are measured on a hydrometer either at the reference temperature or at any other convenient temperature.
• Values obtained as density, API gravity or relative density can be converted to equivalent values in other units at intermittent reference temperatures by with the help of the Petroleum Measurement Tables.

Proper determination of the gravity of crude oils and crude petroleum products is important for the conversion of measured volumes at a measured temperature to volumes at standard temperature of 60° F. Another important factor that determines the quality of crude oils is API gravity.

Application

There are various applications of petroleum hydrometer. Some of it's common applications are in:

• Petroleum Industry
• Particle Size Analysis
• Oil & Gas Plants
• Petrochemical Industry