Efficient Generation and Detection of a Guided Wave in a Pipe using Guided Wave Reflectors

A simple and effective method for generation and detection of a guided wave in a pipe was proposed using an iron hose-fixing belt as a reflector of the guided wave. The reflector is located (2n+1)λ/4 (n=1,2,3,,,) apart from a guided wave sensor in axial direction for the effective generation or detection in the magneto-strictive transduction. The reflector setting is determined under the consideration to the distance between the sensor and the reflector as well as phase inversion at the reflector. In above reflector setting, large amplitude is obtained because multiple-reflection between the reflector and the sensor occurs under phase matching conditions. In this paper, the principle of the method was first described. Experiments were carried out with the non-dispersive T(0,1) mode to verify the principle in comparison to a simple theory.