To check the integrity of the pile (drilled shafts) using the CLS method, it is necessary to install at least three pipes on the reinforcing cage. Pipes Ø38 mm are placed at an equal distance from each other (observed in a horizontal plane). Then they are filled with water, and transceivers are inserted into them, which are pulled from the bottom of the pile to the top, and between them the arrival time of the ultrasonic wave is measured. Unlike the PIT method, the CSL method has the ability to detect geometrically smaller anomalies given the resolution of the test.