SPECIFIC GRAVITY

Flow specific gravity / Absolute specific gravity is defined as the ratio of weight of solids of given volume to the weight of standard fluid (water) of some volume(Vs). 

We usually take water as a reference substance.

We know the density of water varies with respect to its temperature so we take the densest water which is at 4^oC temperature

(OR)

It is defined as the ratio unit weight of solids to the unit weight of standard fluid(water).

               

G (or) Gs = (weight of solids of given volume)/ (weight of water having some volume) 

Range of G

For inorganic soil :- 2.65 to 2.80

For organic soil :- 1 to 2

If the take substance is lighter than water (reference substance), than the Specific Gravity is < 1.

If the taken substance is Heavier than water( reference substance), than the Specific Gravity is >1.

                Specific Gravity >1 (Substance if heavier)

By this we can find out the weight of substance,

Weight of substance = Specific gravity x weight of water at 4^oC temperature