NOTE 8—Because of the difficulty of securing the same tension in all
the filaments and because of slippage in the clamps, erratic results are
frequently obtained with zero-twist multifilament yarns unless a small
amount of twist is inserted before testing.Atwist of 14 6 1 tpcm/=T (36
6 3 tpi/=T ) or 43 6 4 tpcm/=D (110 6 10 tpi/=D ) where T equals
yarn number in tex and D equals yarn number in denier, is usually
satisfactory. But, for unfamiliar materials it may be necessary to test with
several different twist levels and determine the maximum breaking force.
Twist a test specimen length that is about 225 mm (9 in.) longer than the
gage length.