A Zahn Cup is no different than any other precision quality control instrument. It needs to be calibrated from time-to-time, based upon its frequency of usage. The standard oils used for calibration are available from Bay press Services. Refer to the chart when inquiring about calibration oils for your specific Zahn Cup. It is necessary to time the liquid flowing from the cup, accurate to a tenth of a second. For this purpose, Bay press Services now offers a digital stopwatch, part # MIS-SW.
The following table provides specifications of the various cups:
All viscosity standards are packaged in sealed, dark glass bottles. Net content of each bottle is 0.47 Liter (1 Pint). A label on each bottle gives the Standard Name, Lot No., Termination Date, Viscosity in Centistokes at 25.00C (77.00F)* and a statement that the standard “is prepared expressly for Paul N. Gardner Co., Inc., P.O. Box 10688, Pompano Beach, FL 33061-6688” by the Cannon Instrument Company and that data on the standard is traceable to the National Institute of Standards and Technology. A Material Safety Data Sheet (M.S.D.S.) accompanies each bottle of oil.
|Cup Number||Seconds Range||Centistoke Range||Midrange Sensitivity¹||Calibration Oil Number²|
|1||40 to 60||10 to 36||1.3||G-10/19|
|2||20 to 60||19 to 156||3.3||G-60/117|
|3||12 to 60||64 to 596||10.5||G-200/458|
|4||10 to 60||79 to 784||13.9||G-200/458|
|5||10 to 60||161 to 1401||24.2||G-350/878|
|¹ Stated as centistokes per second of efflux time.
² Centistoke values are nominal – actual values printed on labels
Please note that these items are special order and are not returnable.