In-Line Ultrasonic Monitoring for Sediments Stuck on Inner Wall of a Polyvinyl Chloride Pipe

Table 2

The time of flight and the measured thickness of PVC sheets.

Specimen	T3	T5	T8	T10	T15	T22
Time of flight (s)	2.65	4.23	7.13	8.63	13.0	19.7
Actual thickness (mm)	3.0	5.0	8.0	10.0	15.0	22.0
Measured thickness (mm)	2.99	4.77	8.05	9.74	14.64	22.24
Error (%)	0.19	4.52	0.61	2.59	2.39	1.11