Testing of industrial products - Aggregates for construction

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

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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 1	Level 2	Level 3
Number of laboratories included	N	18	18	19
Average	X	0.539	1.140	1.521
Repeatability standard deviation	S_r	0.021	0.042	0.047
Reproducibility standard deviation	S_R	0.057	0.137	0.102
Repeatability limit	r	0.059	0.118	0.131
Reproducibility limit	R	0.160	0.383	0.284

Table 2. Functional relationships.
Sulfur contents (% by mass).
	Functional relationship
Repeatability standard deviation	S_r = 0.006 + 0.029 X
Reproducibility standard deviation	S_R = 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 1	Level 2	Level 3
Repeatability coefficient of variation	C_r	3.9	3.7	3.1
Reproducibility coefficient of variation	C_R	10.6	12.0	6.7