Ultrasonic measurement waveguide rod and ultrasonic measurement instrument

Abstract

An ultrasonic measurement waveguide rod which is easy to manufacture and is capable of preventing a noise echo. An ultrasonic flaw detection waveguide rodis arranged with a probe on one axial end thereof and a contact surface to be brought into contact with a test piece on the other end thereof. The cross-sectional shape of the rodperpendicular to the axial direction is a polygon having sides any one (A) of which is not parallel to any of the other sidesB,C,D. Since at least a pair of the sidesA,C opposed to each other are not parallel to each other, an ultrasonic wave P is allowed to reflect off outer surfaces making up the nonparallel sidesA,C, enabling the ultrasonic wave P to be prevented from returning to the probeas a noise echo. For example, the ultrasonic wave component reflected perpendicularly by one outer surface is reflected by the opposite outer surface and travels toward the outer surface having the sideD. Hence, an echo or a noise hardly returns to the probe.