Navigating Zahn-Type Viscosity Cups: Unveiling Variances for Precision with GARDCO Cups

Different manufacturers have replicated the Zahn cup, leading to significant variations in efflux time between cups of the same make, production runs, and even within the same lot. Variations exceeding 50% have been observed.

Original specifications were based on early G.E. Zahn Cups, which lacked calibration, resulting in varying efflux times between cups.

Two calibrated Zahn-type cups are manufactured to align with past and current specifications: the GARDCO S90/Zahn Signature Dip Cups and the GARDCO EZ Zahn (ASTM) Dip Cups.

The GARDCO S90/Zahn Signature Dip Cups cater to older specifications. Specification sheets should now include Zahn cup type (EZ or S90/Zahn Signature), cup number, and efflux time details. Only use CALIBRATED cups displaying the GARDCO (Paul N. Gardner Co., Inc.) nameplate.

Advantages

1. The EZ to S90/Zahn Signature Seconds Conversion Charts by GARDCO facilitate the conversion of S90/Zahn Signature Dip Cup readings to ASTM D 4212 readings. This preserves established records with S90/Zahn Signature Dip Cups and allows inversion to ASTM D 4212 readings if required. While the cup Constants and Formulas for the S90/Zahn Signature Dip Cups differ from ASTM Specification D 4212, sets of graphs illustrating these variations are available upon request.
2. GARDCO Cups provide reliable, credible, and accurate readings.
3. EZ Cups are calibrated within 3% tolerance.
4. S90/Zahn Signature Dip Cups are calibrated within 5% tolerance.
5. All GARDCO Cups can undergo calibration and come with Calibration Charts to convert efflux time in seconds to viscosity in Centistokes.
6. A "Viscosity Cup Equivalent Chart" in wall size allows conversion of efflux times in seconds to viscosity in Centistokes for all 45 cups manufactured and calibrated by Gardco.
7. All GARDCO cups undergo calibration using standard liquids traceable to the National Institute of Standards and Technology.
8. Both GARDCO EZ & GARDCO S90/Zahn Signature dip cups are eligible for Calibration Certification under ANSI/NCSL Z540-1 as applicable.
9. Oils used to standardize GARDCO Cups comply with ISO 9002.
10. Avail the 20% trade-in allowance on your old Zahn Type cup when purchasing a new EZ cup (Dealers Excluded). (Dealers Excluded).

What You Get When Buying a Gardco Viscosity Cup

• Comprehensive cup usage descriptions, accessories, and pricing.
• Set of 5 conversion charts correlating efflux time to Centistoke viscosity.
• Calibration Oil Temperature/Viscosity charts provided for all 5 cups.
• FAQs addressing queries about viscosity cups.
• Usage guidelines included.
• Step-by-step instructions for GARDCO viscosity cup calibration.
• Details on viscosity cup calibration liquids along with pricing.
• ANSI/NCSL Z540-1 Traceability Statement provided.
• Set of five charts facilitating the conversion of S90/Zahn Signature efflux time to EZ efflux time available upon request.

Watch Out For All Those So-Called “Zahn-Type” Viscosity Cups Out There

The products and reputation hold immense value, demanding careful consideration when choosing a "Zahn cup."

Despite the shared designation of being a "Zahn-type" cup, multiple producers offer varying products. With each purchase of a cup from the same maker, the likelihood of encountering slight differences compared to existing ones remains high.

Why Are All These Cups Out There Different?

1. Most available cups fail to meet the stringent requirements of ASTM and ISC Specifications. Gardco EZ Cups meet and exceed the standards set by ASTM D-4212 and ASTM D-816. The Calibration Oils utilized for standardizing EZ Cups comply with ISO-9002 standards.
2. None of the cups provides a Drain Time Warranty of 3% based on certified viscosity standard oils—except for Gardco Calibrated EZ Cups.
3. The majority of available cups lack certification for liquid calibration. Gardco EZ Cups, however, are fully calibrated.
4. None of the cups on the market offers printed fundamental viscosity information, technical details about cup calibration, etc. Gardco EZ Cups stands out by providing comprehensive information on the use, calibration, and more.
5. No other cups possess copyrighted conversion charts converting tenths of seconds into centistoke viscosity. Gardco EZ Cups include the Conversion Charts free of charge.
6. Some cups may have off-center orifices. Gardco EZ Cups, in contrast, feature perfectly placed orifices.
7. Certain cups have oval or irregularly shaped orifices. Gardco EZ orifices maintain perfect roundness.
8. Some cups lack instructions for use. Gardco EZ Cups not only provide complete instructions but also include a Conversion Chart.
9. Some cups lack an identity nameplate. Gardco EZ Cups feature highly informative nameplates.
10. Other cups lack copyrighted Conversion Charts and formulas for instant conversion of tenths of seconds efflux time into basic centistoke viscosity. Gardco Calibrated EZ Cups include copyrighted Conversion Charts and formulas for this purpose.
11. No other cups in the market offer a copyrighted wall size Viscosity Equivalent Chart enabling conversion between various cups, including all 46 Efflux Cups manufactured by the Paul N. Gardner Company. Gardco provides this exclusive chart valid only for Calibrated Gardco Cups. Request literature for details.
12. None of the other cups available can be documented as comprehensively as Gardco (Paul Gardner Company) Cups.
13. Other cups lack the option for a trade-in with a 20% allowance, unlike Gardco, which offers a 20% discount when trading an old Zahn-type cup for a new Calibrated EZ Viscosity Cup.
14. Many cups in the market exhibit unreliable results, varying between production runs. Gardco EZ Cups maintain a guaranteed accuracy of 3% consistently, year after year, upon leaving their manufacturing plant.
15. Cups from foreign and domestic firms often lack reliability guarantees, admitting differences between cups. Purchasing an uncalibrated cup is akin to acquiring a yardstick without any measurements. In contrast, Calibrated EZ Cups offer a standard basis of reference with a guaranteed 3% accuracy year after year from Gardco's manufacturing plant.
16. None of the cups available come with a Calibration Certificate meeting MIL-STD 45662A except for Gardco EZ Cups, which qualify for certification under Mil Std 45662A. Inquire about certification pricing.
17. Most cups do not provide Certified Calibration Oils upon request. Gardco offers "G" Series Certified Calibration Oils meeting ISO standards for use with EZ cups. Request information for details.
18. The majority of cups lack technical assistance on viscosity matters via phone or fax. Gardco provides continuous support through the Physicist to assist customers in using Viscosity Cups.
19. No other cup provides conversion information between two cup types except Gardco. They offer individual and/or sets of Conversion Charts translating readings from all five Gardco Zahn Signature Cups to all five Gardco EZ Cups. Inquire for details. Additionally, Gardco presents a wall size Viscosity Equivalent Chart applicable to all 35 Gardco Efflux-Type Viscosity Cups, encompassing various cup types like Zahn Signature Cups, EZ Cups, Ford Dip Cups, Standard Ford Cups, Fisher Cups, ISO Cups, ISO Dip Cups, and Din Cups.
20. Although some cups on the market are priced lower than an EZ cup, quality often aligns with the price. Investing a few dollars more in an EZ Cup ensures accurate, reliable service for many years if handled correctly. Opt for the precise, Calibrated EZ Cup carrying the trusted Gardco name.

Trade-In Those Old Uncalibrated Cups

1. It is important to remember that Calibrated EZ cups will not deliver the same efflux time readings as uncalibrated cups previously used. EZ Cups comply with specifications, enabling users to determine material viscosity using the furnished Conversion Chart with each cup. This chart translates efflux time in seconds to centistokes viscosity, establishing a standard reference.
2. It is crucial to note that returns for viscosity cups cannot be accepted. Once these cups interact with coatings, paint, ink, or other substances, they cannot be restored to their original state. It is advisable to confirm the desired cup size before making a purchase.

This information has been sourced, reviewed and adapted from materials provided by Paul N. Gardner Company, Inc.

For more information on this source, please visit Paul N. Gardner Company, Inc.