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#ASTM D 4212 UPDATE#

A wall size "Viscosity Cup Equivalent Chart" allows you to convert efflux times in seconds to viscosity in Centistokes for all 45 cups made and calibrated by Gardco.

All GARDCO Cups can be calibrated and furnished with a set of Calibration Charts to convert seconds efflux time to viscosity in Centistokes.

S90/Zahn Signature Dip Cups are calibrated within 5% tolerance.

EZ Cups are calibrated to within 3% tolerance.

GARDCO Cups give reliable, credible, accurate readings.

Sets of graphs with flow curves detailing these differences are available on request. This will allow you to maintain the records you have established with your S90/Zahn Signature Dip Cups, and also enable you to invert to ASTM D 4212 readings if necessary, even though the cup Constants and Formulas for the S90/Zahn Signature Dip Cups differ from ASTM Specification D 4212.

You can convert S90/Zahn Signature Dip Cup readings to ASTM D 4212 readings using the EZ to S90/Zahn Signature Seconds Conversion Charts by GARDCO.

Only use CALIBRATED cups with a GARDCO (Paul N.

#ASTM D 4212 UPDATE#

Be sure to update your specification sheets and literature to include the type of Zahn cup (EZ or S90/Zahn Signature), the cup # and the efflux time in seconds. GARDCO S90/Zahn Signature Dip Cups are designed to meet the earlier specifications. These two cups are the GARDCO S90/Zahn Signature Dip Cups and GARDCO EZ Zahn (ASTM) Dip Cups. We make two calibrated Zahn type cups that do differ in efflux time in seconds in order to meet both past and present specification requirements. Unfortunately, such cups were not calibrated which often resulted in variations of efflux time in seconds from cup to cup.

Some original specifications were based on the early G.E. Differences of over 50% have been recorded. Today these words can still be found in many technical specification sheets and literature, but today the phrase can be misleading, erroneous and meaningless because many makers have copied this cup and their efflux time in seconds can greatly differ from one make cup to another make cup, from one production run to another, as well as from one cup to another in the same lot. Tensile set is expressed in percent and is calculated by dividing the change in length of the test sample by the initial length.Fifty-eight years ago it meant just what it says. This provides a gauge length (benchmark) 25mm (1 inch) long and a gauge width of 6mm (0.25 inch). Die C has an overall length of 115mm (4.5 inches) with a narrow section 33mm (1.31 inches) long. The specification describes 6 options for the sample dimensions, but the preferred sample is "Die C". After the relaxation period, the final distance between the marks are measured.ĪSTM D 412 specifies a dumbbell shaped specimen.

The samples are then released from the fixture and allowed to relax for 10 minutes. The fixture stretches the samples to the specified elongation and holds them for 10 minutes. The samples are carefully mounted in the test fixture to provide uniform alignment and position. The initial length between these marks is measured for each sample. Two marks are precisely placed on each test sample at the ends of the gauge length of the dumbbell shaped specimens. Test samples are typically die cut from large sheets. This elongation consists of both permanent and recoverable components - thus the time for stretching and recovery are important factors, and both are specified by D 412. Tensile set testing of a rubber or thermoplastic elastomer evaluates the residual elongation of a test sample after being stretched and allowed to relax in the specified manner. Tensile Set of Rubber and Thermoplastic Elastomers ASTM D412