• S90/Zahn Signature Dip Viscosity cups are an improved version of the time honored Zahn Signature viscosity cups. GARDCO is the only producer authorized to use the Zahn name and has added the S90 designation to identify the improved viscosity cups manufactured on new state-of-the-art equipment to insure optimum quality and uniformity.
  
  
• Calibration of the S90/Zahn cups match the earlier Zahn Signature cups.
  
  
• Conversion formulas and tables relating cup efflux time in seconds to viscosity in centistokes are identical for both series of cups.
  
  
• S90/Zahn cups qualify for certification under ANSI/NCSL Z540-1 or ISO/IEC 17025:2005, ISO 9001:2008, as applicable.
  
  
• S90/Zahn cups are calibrated with standard "G" series oils traceable to the National Institute of Standards & Technology.
  
  
• "G" series calibration oils are produced in accordance with ISO 9002.

NOTE: Efflux time from these cups does not meet ASTM specifications, but tables are available for converting S90/Zahn cup efflux time to EZ™ Zahn cup efflux time which complies with ASTM D 4212.