Calculating the Specific Gravity
– Read off the temperature of the liquid
– Using the tables at the back of this manual, find the density
ρ
(fl) which
corresponds to the temperature measured for the liquid you are using
– Calculate specific gravity using the following formula:
W (a) · [
ρ
(fl) – 0.0012 g/cm
3
]
ρ
=
+ 0.0012 g/cm
3
0.99983 G
W (a) and G in g;
ρ
(fl) in g/cm
3
G = W (a) – W (fl)
Determining the Specific Gravity of Solids with a Density Less Than 1 g/cm
3
There are two different methods for determining the specific gravity of solids with
a density less than 1 g/cm.
Method 1:
For this method, distilled water is still used as the liquid causing buoyancy, but the
pan hanger assembly is replaced by the sieve for immersing samples.
To determine the sample’s buoyancy, float it on the surface of the water and then
immerse it using the sieve.
It is also possible to use forceps or a similar tool to place the sample directly under
the sieve (without removing the sieve from the frame).
If the buoyancy of the substance to be measured is so high that the weight of
the sieve is not enough to immerse the sample, increase the weight of the sieve by
adding an additional weight to the upper pan on the frame.
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