Application of Multiparameter Kalman Filter in Ultrasonic Water Meter

Table 2

Data collation and analysis before and after filtering.

Before filtering	Flow velocity (m/s)	10	10.2	10.1	9.8	10.2	10.1	10.2	10.1	10
	Temperature (°C)	25	25.3	25.5	24.9	25.3	25.1	25.3	25.2	25
	Speed of sound (m/s)	1494.463	1495.234	1495.744	1494.204	1495.234	1494.720	1495.234	1494.977	1494.463
	Time difference (ns)	895.4884	912.4562	902.8941	877.8824	912.4562	904.1313	912.4562	903.8204	895.4884
After filtering	Flow velocity (m/s)	10	10.0264	10.0348	9.9954	10.0322	10.0449	10.0579	10.0661	10.0531
	Temperature (°C)	25	25.0149	25.0377	25.0301	25.0435	25.0463	25.0491	25.0565	25.0537
	Speed of sound (m/s)	1494.463	1494.501	1494.560	1494.540	1494.575	1494.582	1494.589	1494.608	1494.601
	Time difference (ns)	895.4884	897.806	898.488	894.983	898.237	899.365	900.521	901.232	900.077