ALTANA Weight per Gallon Cups - Manual (Page 5)

The larger Imperial Cup contains 100.0 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 British Imperial Gallon. This weight in
pounds is multiplied by 0.10 to obtain the specific
gravity or the net weight of the cup is divided by
100 to obtain this figure directly.
Determination of Density and Specific Gravity
Density Specific Gravity
(lbs./gal.) (relative to water)
Regular U.S. Cups g of sample x 0.1 lbs./gal. x 0.12
or or
g of sample : 10 g of sample x 0.012
Midget Cups g of sample lbs./gal. x 0.12
or
g pf sample x 0.12
Regular Imperial Cups g of sample x 0.1 Ibs./gal x 0.10
or or
g of sample : 10 g of sample x 0.01
Importance of Temperature Control:
All weight per gallon cups are calibrated with di-
stilled water at the factory before shipment so that
the correct net weight of water is retained in the
cup at the prescribed temperature of 77°F (25°C).
This same standard temperature is recommended
when using these calibrated cups. Volume expan-
sion or contraction of both the cup and sample will
cause errors if the temperature is not kept under
control. In determining an absolute density value
both the cup and its contents must be brought to
the standard calibration temperature of 77°F or
Operation
4