Table 5. . Performance of different calibration models, weights and transformations in terms of quality control and calibrator precision and accuracy.

Model	Weighting	Transformation	QC rank		Cal rank	Rank sum	Final
			Imprecision	%Accuracy	%Accuracy
Quadratic	None	log-log	4	1	1	6	1
Quadratic	1/X	None	2	3	2	7	2
Linear	None	log-log	3	2	2	7	2
Linear	1/X	None	1	4	4	9	4
Quadratic	None	None	6	5	5	16	5
Linear	None	None	5	6	6	17	6*

CV: Coefficient variation; QC: Quality control.