Fisher Viscosity Cups

• Designed with a “snap in, snap out” type orifice, that permits coverage of the complete viscosity range with one cup and can be replaced if damaged rather than requiring replacement of the entire cup.
• Conversion formulas and table relating efflux time in seconds, to the nearest tenth of a second, to viscosity in centistokes are furnished with each Gardco/Fisher viscosity cup.
• Gardco/Fisher cups are not matched by any other such cups, either with respect to the advantages listed above, in highest quality of workmanship and in continuing quality control procedures.
• Qualifies for certification under ANSI/NCSL Z540 or ISO/IEC 17025, ISO 9001 as applicable. Conforms to ISO 9000 when ordered with calibration certification.
• Calibration of the new Gardco/Fisher cup is traceable to the National Institute of Standards and Technology.
• Gardco/Fisher cups are machined from solid bar stainless steel with brass, readily removable orifices. The support rods are stainless steel.
• The stainless steel support rods are offset from the side of the cup and secured to the cup sidewall below the cup rim. This eliminates errors due to test material drainage from support surfaces.
• Separation of the support rods from the cup by 18% and securing the rods to the cup below the cup rim provides best possible conditions for cleaning.
• Gardco/Fisher calibrated viscosity cups are designed, manufactured, calibrated and sold only by the Paul N. Gardner Company.

The Fisher series of viscosity cups as originally designed and produced, provided some advantages over other existing dip viscosity cups. They accommodated a larger sample of the test material. The orifice was considerably longer than its diameter resulting in cup efflux time more closely proportional to viscosity. However, there were deficiencies in the design. The cup was difficult to clean. It was costly to produce and to calibrate. A damaged or enlarged orifice resulted in necessity for replacement of the entire cup.

The Gardco/Fisher viscosity cups retain the original internal cup dimensions and the same orifice length and diameter but with the following improvements: The weight of the new cup has been reduced to 44% of the weight of the original cup for easier temperature control when cup and material are not at the same temperature. The orifices are of the readily replaceable type permitting coverage of the complete viscosity range with one cup and interchangeable orifices. The orifice may be readily replaced if damaged rather than requiring replacement of the entire cup. The design of the lower portion of the cup eliminates hard to clean areas. The design directs the flow of all test material from the outside of the cup away from the efflux stream improving cup accuracy. Rod supports are designed and secured to the cup in a manner to prevent drainage to the inside of the cup and to provide easier cleaning. In addition to physical improvements, the cups are furnished with conversion formulas and a table which relates the nearest tenth of a second of total efflux time to viscosity in centistokes. This table is particularly useful in determining efflux time in seconds when viscosity in centistokes is known.

The Gardco/Fisher viscosity cups are calibrated at time of manufacture to within 2% of target efflux time. This calibration is with standard oils traceable to the National Institute of Standards and Technology. At an additional cost any cup/orifice combination is available with a CERTIFICATE OF CALIBRATION. The procedures and conditions of calibration on which the certificate is based qualify under ANSI/NCSL Z540 or ISO/IEC 17025, ISO 9001, as applicable, & conforms to ISO 9000 when ordered with certification.

The Gardco/Fisher cups are produced to very close mechanical tolerance in elaborate jigs and fixtures. Such equipment not only insures that each cup is correctly produced but also that all cups are identical. All parts of the cup are of stainless steel except for the orifice and the name plate.