Mean Density of Fluids

Mean Density of Fluids 

Mean density is the average amount of mass within a volume for a substance.  Note, volume of a material is often highly subject to the temperatures, since materials expand as they warm.  For that reason, mean densities of substances are often cited with a set of nominal conditions such as temperature and barometric pressure. 

The formula for mean density is:

μD = V / m

where:

• μD = mean density
• V = Volume in units like gallons or liters
• m = Mass in units like kilograms or pounds

Mean density is also often indicated as the Greek symbol rho (ρ).

The mean density of fluids can be useful since fluids (liquids and gases) conform to the shape of their containers.  This is why it is possible to use the mean density of a substance and the dimensions of its container to estimate the weight/mass of the substance in the container.