Abstract: In a process for monitoring a device for automatically detecting and evaluating surface cracks by means of magnetic powder or the dye penetration process comprising an image pick-up camera and a digital image processing and control unit, a typical defect pattern is projected by means of a projector onto the surface of the article to be examined in the pick-up region of the image pick-up camera and registered, and a defect indication is triggered if the device ceases to operate reliably.

Abstract: A process and device for producing a radiographic image of a body employ a source of high-energy radiation arranged on one side of the body and a pick-up device arranged on the other side of the body, a real-time system for reproducing the radiographic image having a television camera and a screen, and a computer-tomograph to evaluate the radiographic image row-wise and to display a cross-section of the radiographed body on the screen. By means of the real-time radiographic image a cross-section is selected and represented computer-tomographically. In this manner in the real-time radiographic image the location can be determined of which a layer image is necessary in order to recognise defects in the body being radiographed.

Abstract: A magnetic coupling for translatorily movable bodies that is made in one position, is arranged so that it can be broken, without external control, in another position. For this purpose the first body has a coupling element of permanently magnetic or magnetizable material, the second body has at least one complementary coupling element of permanently magnetic or magnetizable material, and a third body has a coupling element of permanently magnetic or magnetizable material cooperating with the second body. Arranged between the complementary coupling element of the second body and the coupling element of the third body that is a spacer which can be moved as desired between the working positions.