Weight per Gallon Cups also known as Density Cups, Specific Gravity Cups or Pycnometers are used to quickly and accurately determine the weight per gallon, and also the specific gravity of paints, lacquer, pastes, semi-pastes, and other liquid or semi-liquid materials.
|Model:||US Standard Weight Per Gallon||Mini Weight Per Gallon||British Standard Weight Per Gallon||Tarelite Weight Per Gallon|
|British Standard||U.S. Standard|
|Capacity:||Accommodates 83.205 grams of water at 77.0° F (25.0°C)||Accommodates 8.3205 grams of water at 77.0° F (25.0°C)||100cc accommodates 99.705 grams of water at 77.0° F (25.0°C)||100cc||83.2|
|Weight:||Cup with Cover, approximately 130 grams||Cup with Cover, approximately 56 grams||Cup with Cover, approximately 143 grams||44g||47g|
|Pounds per U.S. Gallon =||Gram Weight of U.S. Standard Cup Contents x 0.1000||Gram Weight of Mini Cup Contents||-||Gram Weight of Cup Contents x 0.10000|
|Specific gravity =||Gram Weight of Cup Contents x 0.01202||Gram Weight of Cup Contents x 01202||Gram Weight of Cup Contents x 0.01001||Gram Weight of Cup Contents x 0.01001||Gram Weight of Cup Contents x 0.01202|
|Pounds per British (Imperial) Gallon =||-||-||Gram Weight of British Standard Cup Contents x 0.1||Gram Weight of Cup Contents x 0.1000||-|
|Grams per liter =||-||-||-||Weight of contents (in grams) x 10||-|
|Kilograms per Liter =||-||-||-||Weight of contents (in grams) ÷ 100||-|
|Measurements are normally made at a temperature of 77.0°F (25.0°C)|
Cup Factor - Comparative results on different materials measured in the same cup are accurate to within the limits of accuracy of the balances used. Comparative results between cups may be somewhat improved by determining a cup factor as follows: Divide 83.205 by gram weight of water at 25°C (77°F). Example: if the cup actually holds only 83.000 grams, divide 83.205 by 83.000 which equals 1.0025. Multiply all cup readings by this factor of 1.0025. In the same manner if the cup holds 83.400 (grams) divide 83.205 by 83.400 which equals 0.9977. Multiply all readings by this factor of 0.9977.
Care of Cups - There are numerous grades of Stainless Steel and all of them will corrode under adverse environmental conditions. A common type of Stainless Steel is the 300 Series which is most usually produced in sheets for forming into vats, kettles and the like. This series is highly resistant to corrosion under normal use conditions. It is very difficult, however, to machine this type where close tolerance and smoothness of finish are requirements. Prior to the middle of 1989, Gardco weight per gallon cups were fabricated, using Series 300 Stainless Steel for the sidewall and the more easily machined, but less corrosion resistant, Series 400 Stainless Steel for the base and cover. Since then, with the installation of state of the art computer controlled metal cutting machinery, all Gardco weight per gallon cups are machined from Series 300 Stainless Steel solid bar stock. With the exception of a daily cleaning, Gardco weight per gallon cups are essentially maintenance free. If it is expected that a cup will be stored for an extended period of time, it is recommended that it be given a light coating of protective oil. With only these precautions, the cup should provide long and satisfactory service and retain its original attractive appearance.
ISO 2811, DIN 53 217, ASTM D1475
Meet ASTM Methods of Test
Qualify Under ANSI/NCSL Z540-1 as Applicable
Conform to ISO 9000 When Ordered With Calibration Certification
As a quality control check, errors in composition of a paint will usually be indicated by variations in the pycnometer value. In normal use in the Paint Industry, many specifications will allow a tolerance of about 0.2 pounds per gallon. Any deviation that is larger than this would make the paint suspect regarding the proper amount of ingredients in the batch.
To check the actual capacity of your cup proceed as follows: