[Retracted] Design of Water Quality Monitoring System in Shaanxi Section of Weihe River Basin Based on the Internet of Things

Table 2

Indication error and repeatability error under different water quality conditions.

Test items		Theoretical value	Detection value				Error	Repeatability
Test 1	pH	6.0	5.94	6.14	6.09	6.05	−0.003	0.11
		6.5	6.39	6.45	6.37	6.67	−0.019	0.12
		7.0	6.83	6.88	7.15	6.82	−0.03	0.16
Test 2	Temperature (°C)	15	14.6	14.38	15.43	15.09	0.018	0.44
		20	19.7	20.32	20.14	20.6	0.068	0.56
		25	24.3	24.6	25	25.3	−0.13	0.39
Test 3	Conductivity (Us/Cm)	300	303.4	297.6	301.9	302.6	0.042%	0.12%
		450	457.9	452.8	450.9	452.9	0.13%	0.22%
		500	508.4	505.9	495.7	504.9	0.15%	0.28%
Test 4	Dissolved oxygen (Mg/L)	3.0	3.04	3.08	3.02	2.91	0.08%	0.36%
		5.0	5.07	5.01	5.15	5.05	0.43%	0.54%
		6.0	6.15	6.02	6.17	6.09	0.55%	0.65%