Testing of industrial products - Aggregates for construction

Precision values obtained from the cross-testing experiment on the Schlagversuch

Note. For all the tables here, "stragglers" have been included in the calculations, and "outliers" have been excluded.


Table 1. Repeatability and reproducibility.
Level 1Level 2Level 3
Number of laboratories includedN 141516
AverageX 11.021.627.7
Repeatability standard deviation Sr10.1770.2230.255
Reproducibility standard deviation SR10.4080.6061.225
Critical range Wc1.01.21.5
Repeatability limit r10.50.60.7
Reproducibility limit R11.11.73.4

Table 2. Functional relationships.
Functional relationship
Repeatability standard deviation Sr1 = 0.125 + 0.0046 X
Repeatability limit r1 = 0.350 + 0.0129 X

Table 3. Repeatability and reproducibility standard deviations
expressed as coefficient of variations.
Level 1Level 2Level 3
Repeatability coefficient of variation Cr11.61.00.9
Reproducibility coefficient of variation CR13.72.84.4

Table 4. Sensitivity ratios.
Level 2 - Level 1 Level 3 - Level 2Level 3 - Level 1
Repeatability 37.218.053.8
Reproducibility 14.54.512.9