Abstract: A method of testing the position of an edit point between an edited magne tape packed in a cassette and a leader spliced ahead of the recording or a trailer spliced after the recording, includes determination of a distance of the edit point from a cue tone situated, for example, at least before the beginning of the recording, or from the end of the recording and generating first and second output signals commensurate with an optical measurement of the edit point and an inductive measurement of the recorded cue tone. In dependence of the position of the recorded cue tone behind the leader or ahead of the trailer as viewed in tape travel direction, a time difference, such as, between the ascending flank of the second output signal and the descending flank of the first output signal, is determined. The determined time difference is then compared with upper and lower limits which define a tolerance range for the position of the edit point before or behind the recorded cue tone.

Abstract: Light conductive fibers being embedded as crack monitors in reinforced compound material are protected as follows. During laminate assembly the fiber ends are slipped into relatively short teflon hoses but being provided to be at least in parts embedded in the compound parts to be made; the ends of the hoses that will be embedded are closed with a cold curing laminate resin; the fiber ends with enclosing teflon hoses will be threaded through laminate openings during assembly of the lamination, and the fiber ends with projecting hoses are also inserted in a conical bore of an assembly device; open areas and portions of the compound part adjacent to the conical bore of the assembly tool are filled with laminate resins; a protective cover is then placed onto said bore and over the teflon hose protected fiber ends prior to curing of the part; and the thus prepared part is cured in an autoclave.

Abstract: A system for sensing fractures in a structural component that has a plurality of light conductor fibers attached to or incorporated in the structural component, such as an aircraft body or wings made of fiber reinforced material. The light conductor fibers function as fracture sensors. For this purpose the light supply to each individual fracture sensing light conductor and the interrogation whether a light signal has passed through the light conductors is controlled by a computer. The absence of a light signal at a particular conductor signifies a fracture and this fact may be indicated on a display in the cockpit of an aircraft.

Abstract: An arrangement for detecting cracks within a construction or structure part made of multiple lamina in a compound fashion and wherein at least some of said lamina are made of fibres, being at least partially embedded in synthetic resin, includes light conducting fibres in said lamina taking the place of regular ones of said fibres within a pattern of such fibres either as part of the weaving pattern or as particular interposed layer.

Abstract: The invention relates to a measuring device for determining cracks. Light conductive fibers or film are provided as crack detectors in this measuring device which fibers or films are applied directly upon the construction parts. Light is coupled into these light conductive fibers by means of a coupler and the passage of light is monitored at the free end. A fiber fracture serves as irreversible crack indication.

Abstract: Laminated parts of structural material receive as embedment light transmitting fibers, preferably in addition to reinforcing fibers, and light transmission through the light transmitting fibers is monitored for purposes of determining pattern irregularities and formation of cracks.

Abstract: A centrifuge for biological specimens is constructed to include one or two additional concentric rotors being independently drivable and provided with means for transfer of objects to and/or from the main centrifuge. The rotating specimen is under observation from a stationary observation point.