14.1.1 Repeatability- The diferrence between successive test results obtained by the same operator with the same apparatus under constant operating conditions on identical test material would, in the long run, in the normal and correct operation of the test method exceed the followingvalues only in one case in twenty. Repeatability(r) may be calculated as shown in Eq 12 for all materials covering the full scope of this method.See Table 4 for calculated values.