Abstract: A wheel probe for ultrasonically inspecting a component, such as the wall of a pipe, is of hollow form to define a chamber in which at least one ultrasonic transducer is supported to direct and receive ultra-sound through the wheel probe. The chamber is filled with an acoustic coupling liquid, and at least one resilient diaphragm is provided in the wall of the chamber so as to deflect in response to a difference in pressure thereon and balance the pressure of the liquid with that of the environment about the wheel probe.

Abstract: Disclosed is a wheel probe for use on a pipe inspection vehicle. The wheel probe comprises a annular perspex outer rim with a polyurethane tire mounted on a hub assembly which, with the hub, defines a fluid-tight chamber containing an acoustic coupling fluid. A number of ultrasonic transducers are located inside the chamber and are positioned close to the inside circumferential surface of the rim. The hub assembly is carried by a spring loaded carriage which is secured through which ultrasound will pass.The wheel probe includes a guide wheel on each side. The guide wheels are carried by the carriage but are moveable bodily relative to the center of the hub assembly, and when deflected, they operate on the assembly to move the wheel probe to ensure that the outer rim of the wheel is correctly aligned relative to the pipe.The wheel probe has a number of shields spaced around its periphery.