Abstract: A probe utilizing electrical fields for nondestructive testing of metals is disclosed which is mounted in a hand-held portable housing, or head, having limit switches therein for restricting up and down movement of the probe. Apparatus for selectively engaging the limit switches by the probe driving mechanism, without injury to the internal parts of the head, is also disclosed. The head may be equipped with a slip ring extender also, to enable an operator to use the head in a variety of positions, and the depth setting mechanism for the probe is protected against inadvertent movement during continued usage of the head.

Abstract: A method and apparatus for calibrating a gamma ray inspection system for measuring the wall thickness of a tubular product such as a pipe or the like, the system including a gamma ray beam generating station, means for conveying a tubular product axially past the gamma ray beam, the gamma ray generator being rotated during the axial movement of the tubular product, means for detecting the amount of attenuation of the gamma rays passing through the tubular product, and a calibration block having a first portion with a thickness corresponding to twice the nominal wall thickness of the tubular product to be inspected, and a second portion having a thickness corresponding to a predetermined amount less than the nominal wall thickness. Means are provided for selectively introducing the first portion and the second portion of the calibration block into the gamma ray beam to enable the operator to calibrate the equipment and to be able to detect tubular products which are defective in terms of thickness.

Abstract: Radioisotope camera lock, locking the source isotope in a safe, shielded position in the camera when not in use. The lock prevents the source isotope from being moved to an operative position outside of the camera, unless intentionally released by a key and reverse movement of source pigtail. A hollow lock casing is secured to and has communication with the interior of the radioisotope camera. The source isotope is at the end of a source pigtail and is cranked or pushed from the camera and pulled back into the camera by the cranking mechanism. A stop on the source pigtail cooperates with a lock spool movably mounted in the lock casing. A lock lever pivoted in the lock casing is provided to hold the source isotope in a shielded condition within the camera upon moving the lock to its locked condition. The locking arrangement is such that the source isotope will automatically be trapped in the camera as fully withdrawn into the camera prior to manual locking.