The EZ Zahn Viscosity Dip Cup is the finest, most reliable, ASTM calibrated & documented viscosity cup on the market. It is not matched by any other dip cup of its type, either with respect to the advantages listed below, in highest quality of workmanship or in continuing quality control procedures. All EZ Viscosity Cups are made of stainless steel and are calibrated at our Gardco Service Department.
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The EZ Viscosity Cup Series is a logical and necessary outgrowth of the standardization studies on the Zahn Signature Viscosity Cup and similar cups for the promotion of this most popular type of viscosity measuring instrument as a national and international standard. Not only has this cup been improved with respect to earlier produced cups and designed to comply to the requirements of ASTM D4212 but, in addition, each EZ Viscosity Dip Cup is furnished with a table which permits conversion between efflux time in seconds to the nearest tenth of a second to viscosity in centistokes. This table is particularly useful in determining efflux time in seconds when viscosity in centistokes is known.
For those users who require documented certification of their measuring equipment, the EZ™ dip cups may be ordered, at an additional charge, with a CERTIFICATE of CALIBRATION . This document contains not only information on actual cup calibration with standard oils traceable to the National Institute of Standards and Technology but in addition, this certification also complies to conditions and procedures under the requirements of ANSI/NCSL Z540 or ISO/IEC 17025 as applicable.
The EZ™ Viscosity 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 flow cup are of stainless steel except for the name plate. The following table provides operating range specifications, dip cup midrange sensitivity and recommended Canon calibration oils (standards). Following this table are graphs and mathematical formulas that relate efflux time in seconds to centistoke viscosity.
|Cup Number||Seconds Range||Centistoke Range||Midrange Sensitivity ¹||Calibration Oil Number ²|
|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
EZ™is a Registered Trade Mark of the Paul N. Gardner Company, Inc. - The information contained herein, or supplied by us or on our behalf in any other manner is based on data obtained by our own research and is considered accurate. However, NO WARRANTY IS EXPRESSED OR IMPLIED REGARDING THE ACCURACY OF THESE DATA, THE RESULTS TO BE OBTAINED FROM THE USE THEREOF, OR THAT ANY SUCH USE WILL NOT INFRINGE ANY PATENT. This information is furnished upon the condition that the person receiving it shall make his own tests to determine the suitability thereof for his particular purpose.
Viscosity Cup Care - EZ™ viscosity cups are ruggedly constructed with all parts made of stainless steel, except the nameplate, and will give many years of satisfactory service requiring only thorough cleaning after each use. It is recommended, however, that calibration of the cup be confirmed periodically, or if dropped or otherwise subjected to damage, with the appropriate standard oil selected from the specification table. The listed viscosity value of these oils as shown on the container label is traceable to the National Institute of Standards and Technology.
Guide for removing the G-series calibrating oil from Gardco viscosity cups. - Any remaining material in the cup must be removed by flushing with a suitable solvent. Light naphtha, heptane, octane, highly aromatic solvents, and or any other petroleum-derived hydrocarbon solvent can be used. Varsol® is a commercial solvent that works very well for this purpose. Varsol is a registered trademark of the Exxon Company.
Completely dry the viscosity cup with a lint free cloth. Use a highly volatile solvent for a second cleaning as since any remaining hydrocarbon solvents from the first process will evaporate quickly after the sample has been flushed from the cup. Hypersolve, MEK and Alcohol can be used in aluminum cups and Hypersolve and Alcohol for the stainless steel cups. Acetone is commonly used as the second solvent because of its high volatility and its ability to dissolve traces of petroleum solvents and water.
In the third process a low velocity stream of clean air will be sufficient to evaporate remaining traces of any volatile solvent. Be aware, avoid rapid evaporation of these solvents as this can cool the surface to such an extent that humid air may be brought below the dew point, causing a film of water to form on the cup.
Standard "G" Series Oils - Warning: Silicone fluids should not be used to calibrate viscosity cups. These materials change the interface between the cup surface and the test material and therefore change the cup calibration. The following is taken from ASTM D445: Viscometers used for silicone fluids should be reserved for the exclusive use of such fluids. Solvent washings from these viscometers should not be used for cleaning other viscometers.
Gardco produced viscosity cups are calibrated with standard “G” series oils. These standard calibration oils prepared expressly by the Cannon Instrument Company for the Paul N. Gardner Company are produced in accordance with ISO/IEC 17025, ISO Guide 34, ISO 9001.
Centistokes viscosity of these oils is traceable to the National Institute of Standards and Technology. These oils are available from the Paul N. Gardner Company. Shown in the graph is the viscosity cup number and the standard “G” oil used for its calibration. Normally, cup calibration is at 25 degrees Celsius, shown on the graph by bold lines intersecting with the curve in the circle. Graphs for all cups in the EZ series are included with each cup sold by Paul N. Gardner Company.
Viscosity of most liquids, including the standard oils, are dependent on temperature. Efflux time in seconds for the indicated cup-oil combination from twenty (20) to twenty seven (27) degrees Celsius is shown in the graph. The cup may be checked with the indicated “G” oil with reasonable accuracy within these limits. For best accuracy, the temperature of the standard oil should be 25°C. The standard oil value in centistokes is printed on the standard oil bottle label. Conversion from viscosity to efflux time in seconds is by formula or table which defines the characteristics of the cup. The applicable formula and table are furnished with each cup sold as an additional customer service by the Paul N. Gardner Company and licensed distributors.