Measuring Procedure (for Method 1only)
Determining the Weight of the Sample in Air
– Tare the balance
– Place the sample on the frame weighing pan and weigh
– Record the weight W (a)
Determining the Buoyancy G = W (a) – W (fl)
– Tare the balance again (with the sample on the frame weighing pan)
– Place the sample under the sieve or immerse it below the surface of the liquid
using the sieve
1
)
– Record the buoyancy “G,” which is displayed with a negative sign
Calculating the Specific Gravity
– Read off the temperature of the liquid
– Using the table at the back of this manual, find the density ρ (fl) which
corresponds to the temperature measured for distilled water
– Calculate the specific gravity using the following formula:
W (a) · ρ (fl)
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)
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 in the
liquid; it is better to place the sample directly under the pan using forceps, etc.
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