Specific Gravity

Specific gravity is defined as the ratio of the density of a substance to the density of water.

As it is the density of something divided by the density of something else, the result is a dimensionless (No unit).


It can be expressed as:

SG = ρ something / ρ H₂O

SG = Specific Gravity
ρ something = density of the fluid (usually in kg/m³)
ρ HO = density of water (usually kg/m³)

It's important that both units system match so you can cancel each other.

It doesn't matter if you use SI units or the imperial english system, as long as you use them consistently. Both in SI units or both in the imperial system.

As stated above the result is a dimensionless unit that has the same absolute value regardless if you started using SI or imperial units to get it.

Real World Examples

To be continued



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Materials: Specific Gravity
Specific Gravity
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