Note that there are two measurements of strain in the polymer tests:

*  During the initial part of the test, the extensometer is attached.
   Use the extensometer data at small strains to determine modulus.

*  For overall strains, use the length of the gage length portion of the specimen (fillet to fillet).
   Compute strain using crosshead displacement  / gage length.
   
Since many of the polymer specimens form a neck and draw with a constant cross section, the determination of final true strain using final neck dimensions is NOT valid.

Use ADDITIONAL DATA posted on-line to develop analysis for a full range of cross head rates from 1mm/min to 500mm/min (total of 6 sets of data for each material).