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EZ™ Zahn Viscosity Cups

Article No. 13793

Zahn EZ Viscosity Cup #5

  • EZ Zahn Viscosity Cup #5
  • Download Excel Viscosity Chart HERE

Insta-Visc App


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$173.00 excl. taxes & shipping cost


  • The EZ Flow Cup formula for each cup of the series matches the applicable ASTM formula in D4212 at the recommended calibration level
  • EZ Viscosity Dip Cups are compatible to ASTM D1084 Viscosity of Adhesives and ASTM D816
  • EZ Viscosity Cup calibration is traceable to the National Institute of Standards and Technology (NIST)
  • Calibration and Certification procedures qualify under ISO/IEC 17025 as applicable
  • 3% guaranteed tolerance for EZ Viscosity Cups complies with & exceeds ASTM D4212
  • Conversion table relating efflux time in seconds, to the nearest tenth of a second, to viscosity in centistokes furnished with each EZ™ Dip Cup.
  • EZ Dip Cup orifices are machined rather than drilled to insure exact centering in the cup hemisphere base and a minimum of burr formation. This insures an orifice of specified length and a correct symmetrical efflux stream.
  • The EZ Viscosity Cup 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.
  • The increased separation width of the support rods by over 20% and the lowering of weld to the cup provide best possible conditions for cleaning.
  • Viscosity Cups are non-returnable items. Subject to final sale.

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.

Technical Attributes

  • Data
    Cup NumberSeconds RangeCentistoke RangeMidrange Sensitivity ¹Calibration Oil Number ²
    140 to 6010 to 361.3G-10/19
    220 to 6019 to 1563.3G-60/117
    312 to 6064 to 59610.5G-200/458
    410 to 6079 to 78413.9G-200/458
    510 to 60161 to 140124.2G-350/878
    ¹ Stated as centistokes per second of efflux time.
    ² Centistoke values are nominal - actual values printed on labels

More Information

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.


  1. Select the proper number cup to be used from the Specification Table, which is dependent on the expected viscosity range of the material to be measured.
  2. Insure that the cup is clean and that there is no residual dried material in or around the orifice.
  3. Adjust the temperature, if necessary, of the test material.
  4. Completely immerse the cup into the material to be measured in a location free from bubbles or foam, holding the cup vertically by means of the stainless steel split key ring.
  5. Measure and record the temperature of the material that is encompassed by the cup.
  6. Hold cup vertically by inserting index finger into handle ring. In a quick, steady motion, lift the cup out of the sample material, starting the timer when the top edge of the cup breaks the surface. During the flow time, hold the cup no more than 6” above the level of the sample material.
  7. Stop the timer when the first definite break in the stream at the base of the cup is observed.
  8. Record the number of seconds of efflux time, temperature and the cup number. (Example: No. 2 EZ™ Dip Cup, 48.1 seconds at 25.1°C.) As an option to the preceding step, refer to the Insta Visc viscosity calculator Insta Visc App or conversion table for the cup to determine the centistoke viscosity for the measured efflux time in seconds and record this value and the measured temperature.
  9. Promptly clean the cup unless it will be used immediately for a rerun of the same material. (Use a length of nylon fishing line to clean the orifice.)



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