X1.3 Precision and Bias
X1.3.1 Precision has been determined in terms of the normalized reporting units.
X1.3.2 Repeatability—The difference (r) 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 values below only in
one case in twenty:
O Number r R Number r
0 to 20 4 0 to 20 5
20 to 40 6 20 to 40 10
40 to 100 8 40 to 60 20