Table 7.

Performance comparison of factory and own calibrations for direct regression approach of sensors from ECH₂O family: R² values, average AD (vol %) and RMSE values (vol %).

			Factory Linear Calibration			Own Linear Calibration
Sensor Type	Material	Packing	R2	Average AD (vol %)	RMSE (vol %)	R2	Average AD (vol %)	RMSE (vol %)
ECH2O TE	Soil	Moderate	0.962	2.25	2.88	0.962	1.98	2.31
ECH2O EC-5	Soil	Moderate	0.977	2.97	3.07	0.977	1.54	1.80
ECH2O EC-10	Soil	Moderate	0.968	4.83	5.81	0.968	1.91	2.12
ECH2O EC-20	Soil	Moderate	0.972	4.84	5.83	0.972	1.81	1.97
ECH2O TE	Sand	Loose	0.963	1.34	3.68	0.992	0.49	0.62
ECH2O EC-5	Sand	Loose	0.982	3.40	5.85	0.982	0.77	0.93
ECH2O EC-10	Sand	Loose	0.926	13.06	16.43	0.928	1.45	1.86
ECH2O EC-20	Sand	Loose	0.811	11.90	15.08	0.810	2.17	3.02
ECH2O TE	Sand	Moderate	0.983	1.27	2.80	0.983	0.95	1.11
ECH2O EC-5	Sand	Moderate	0.986	1.56	3.28	0.986	0.85	0.98
ECH2O EC-10	Sand	Moderate	0.917	11.81	15.05	0.917	2.07	2.43
ECH2O EC-20	Sand	Moderate	0.930	11.26	13.93	0.930	1.96	2.23
ECH2O TE	Sand	Compact	0.976	1.35	2.16	0.978	1.19	1.44
ECH2O EC-5	Sand	Compact	0.981	1.29	2.61	0.981	1.09	1.32
ECH2O EC-10	Sand	Compact	0.977	7.18	10.02	0.963	0.38	0.49
ECH2O EC-20	Sand	Compact	0.993	7.87	10.02	0.991	0.75	0.90