Application of Multiparameter Kalman Filter in Ultrasonic Water Meter

Table 4

Comparison of flow velocity and temperature before and after filtering and error analysis.

Speed of sound				Time difference
Before filtering	After filtering	Error	Error analysis (%)	Before filtering	After filtering	Error	Error analysis (%)
1494.463	1494.463	0.00	0	895.4884	895.4884	0.00	0
1495.234	1494.501	0.73	0.05	912.4562	897.806	14.65	1.61
1495.744	1494.56	1.18	0.08	902.8941	898.488	4.41	0.49
1494.204	1494.54	-0.34	-0.02	877.8824	894.983	-17.10	-1.95
1495.234	1494.575	0.66	0.04	912.4562	898.237	14.22	1.56
1494.72	1494.582	0.14	0.01	904.1313	899.365	4.77	0.53
1495.234	1494.589	0.64	0.04	912.4562	900.521	11.94	1.31
1494.977	1494.608	0.37	0.02	903.8204	901.232	2.59	0.29
1494.463	1494.601	-0.14	-0.01	895.4884	900.077	-4.59	-0.51