Determining the Specific Gravity/Density
Determining the Specific Gravity of Solids
Preparation
(Distilled water is used in the description)
– Center the large-diameter beaker
(90 mm d) on the metal platform
– Fill it so that the distilled water
is approximately 5 mm below the rim
– Add three drops of tenside to the
distilled water
– Attach the thermometer to the rim
of the beaker using the retainer clip
– Clean the sample holder with a sol-
vent (especially the wires that will be
immersed) and hang it from the frame
Measuring Procedure
Determining the Weight of a Sample
in Air
– Tare the balance
– Place the sample on the upper pan on
the frame and weigh
– Record the weight W (a)
14
Determining the Buoyancy
G = W (a) – W (fl)
– Tare the balance with the sample on the
upper pan on the frame
– Place the sample in the sample holder
– Record the absolute readout of the
buoyancy "G," which is displayed with
a negative sign
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
ρ =
corr G
W (a) and G in g; ρ (fl) in g/cm
G = W (a) – W (fl)
1
) If you remove the pan hanger assembly
from the measuring device to do this,
make sure that no additional air bubbles
are on it when you re-immerse it; it is
better to place the sample directly on the
pan using forceps or a similar utensil�
1
)
3
]
3
+0�0012 g/cm
3