ALTANA Weight per Gallon Cups - Manual (Page 4)

Operation
1. Mix the material thoroughly before pouring a
representative sample into the cup. Fill the cup
until the liquid level is just below the rim at 25°C or
other agreed upon temperature. Avoid trapping air
bubbles in the sample.
2. Place the perforated lid on top of the cup and seal
it with a careful twisting motion. An excess of the
liquid should ooze (not squirt) put of the small hole
on top of the snugly fitting lid. Wipe off this excess
material, using a soft cloth or tissue paper.
3. Weigh the properly filled cup, (usually to the nea-
rest 0.1 gram), on an appropriate laboratory ba-
lance. A tare weight is available with the 3 sizes of
cups. It can be used as a counterpoise to determine
rapidly the net weight of the sample when an even-
arm or trip balance is used. The weight of the tare
equals the exact weight of the empty cup and its lid.
4. Using the net weight, compute the pounds-per-
gallon density or the specific gravity of the sample
by the following methods.
Calculations:
The Regular Cup contains 83.2 grams of water at
25°C. The net weight in grams of the fluid sample
is divided by 10 to obtain the weight in pounds
per U. S. Standard Gallon. This weight per gallon
is multiplied by 0.12 to obtain a specific gravity or
the net weight of the cup can be divided by 83.2
for a direct conversion to specific gravity.
The Midget Cup has a capacity of 8.32 grams of
water at 25°C. The net weight of the fluid sample
in grams equals the sample‘s density in pounds
per U. S. gallon. To obtain specific gravity, multiply
pounds per gallon by 0.12 or divide the net weight
of the cup by 8.32.
Operation
3