Testing of industrial products - Aggregates for construction

Precision values obtained from the cross-testing experiments on the Total Sulfur test

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


Table 1. Repeatability and reproducibility
Sulfur contents (% by mass).
Level 1Level 2Level 3
Number of laboratories includedN 181819
AverageX 0.5391.1401.521
Repeatability standard deviationSr 0.0210.0420.047
Reproducibility standard deviationSR 0.0570.1370.102
Repeatability limitr 0.0590.1180.131
Reproducibility limitR 0.1600.3830.284

Table 2. Functional relationships.
Sulfur contents (% by mass).
Functional relationship
Repeatability standard deviation Sr = 0.006 + 0.029 X
Reproducibility standard deviation SR = 0.022 + 0.073 X
Repeatability limit r = 0.017 + 0.081 X
Reproducibility limit R = 0.062 + 0.204 X

Table 3. Repeatability and reproducibility standard deviations
expressed as coefficients of variation (%).
Level 1Level 2Level 3
Repeatability coefficient of variation Cr3.93.73.1
Reproducibility coefficient of variation CR10.612.06.7