Intelligent Diagnosis Method for Centrifugal Pump System Using Vibration Signal and Support Vector Machine

Table 2

DI values and standard deviation of DI values of 3 NSPs between two states from original signals.

Two states	In mild step			In medium step			In severe step			DI’s standard deviation
	Normal state and abnormal state	0.35	0.39	0.44	0.56	0.65	0.60	0.82	0.77	0.91	0.24	0.19	0.24
Cavitation and impeller unbalance	0.33	0.20	0.53	0.45	0.41	0.59	0.88	0.75	0.72	0.29	0.28	0.10
Cavitation and shaft misalignment	0.27	0.38	0.34	0.44	0.68	0.41	0.69	0.56	0.95	0.21	0.15	0.33
Impeller unbalance and shaft misalignment	0.42	0.45	0.41	0.60	0.59	0.51	0.73	0.61	0.83	0.16	0.09	0.22