Abstract: A method and apparatus for detecting disbond in laminar workpieces. Energy is transmitted to a workpiece (8) by repetitive impacts. A transducer (12) converts energy emitted from the workpiece (8) to an electrical signal. The energy emitted in response to each of the repetitive impacts is analyzed. After filtering out the DC component (20) and amplifying the signal (30) the maximum amplitude of the energy from each impact is selected (50) and passed to a sample and hold circuit (60). The piecewise linear output of the sample and hold circuit (60) is passed through a low pass active filter (70) prior to recording on a strip chart recorder. The strip chart record is analyzed to ascertain areas of the workpiece (8) having defective clad bonding (7).

Abstract: A filter apparatus (2) is disclosed for filtering out any reoccurring noise (5) present in a defect signal (1) received from a flaw detection device (4) such as an eddy current test probe. Filter circuit means (10) receives the defect signal generated by the flaw detector device and produces an output signal (5) duplicative of any reoccurring noise present therein. A differential amplifier (50) subtracts the output signal (5) of the filter circuit means from the defect signal (1) generated by the flaw detection device and amplifies the difference. A filtered defect signal (9) void of any reoccurring noise is thereby produced.

Abstract: A reel assembly for flexible tubing includes a drum having a conically shaped outer wall. The maximum diameter of the drum is less than the natural cast diameter of the tubing whereby the tubing coils in pressure contact with the inner surface of the outer wall. The friction of the tubing coils against the drum wall provides drive of the reel. Electrical interconnection to the tubing is provided by a cable extending in the central bearing mount and coiled loosely about the central bearing mount thereby allowing for expansion or contraction as the reel rotates.

Abstract: A drive assembly for a probe carrier such as used for inspection and maintenance of a heat exchanger in a steam driven electric power generation plant includes a motor and speed reducer and drive wheel for pushing a probe carrier through the tubes of the heat exchanger. The carrier may comprise nylon tubing, and the drive wheel includes radially mounted wires with the tips of the wires defining a surface for engaging the tubing. An adjustable pressure plate yieldably biases the tubing into engagement with the drive wheel with sufficient pressure for the wire tips to indent the tubing surface but without penetrating the tubing surface whereby an interference drive of the probe carrier is achieved.