The performance of machine learning approach on the CuSO₄ experiment of test dataset.

Normalization approach	Metrics
	R 2	Root mean squared error
Raw	0.9716 ± 0.0023	0.0965 ± 0.0039
Delta	0.9724 ± 0.0026	0.0950 ± 0.0054
Ratio	0.9744 ± 0.0031	0.0915 ± 0.0048