Karl Deutsch Pruf - Und Messgeratebau Gmbh+co. Kg

Estel Hoesch Werke Aktiengesellschaft

Volker K Deutsch

Wolfgang Bottcher

Hermann J Kopineck

Werner F Roddeck

Werner Borchert

Klaus D Mreyen

The invention relates to a method and means for measuring the depth of cracks, using a potential probe connected to a measuring instrument and having two current terminals and additional voltage-measuring terminals (potential probe method). The object of the invention is to eliminate the separate calibration devices needed for the checks and collective measurements necessary when using known potential probes, and to make the check measurements in conjunction with the actual depth-measuring process. This problem is solvable by using a potential probe (S) as per the drawing, where at least two pairs of terminals (1+2, 3+4) having known but different spacings serve as adjustment measuring portions and are connected to an adjustment circuit (JM, UM) in a measuring-instrument microcomputer (M) and an additional pair of terminals (2, 3) having a known spacing serve as a crack-depth measuring portion and are connected to a crack-depth measuring circuit (TM) in the microcomputer. The probe is attached to the workpiece so that the adjustment portions lie on opposite sides of the crack, whereas the crack-depth measuring portion contains the crack.

Method and means for measuring the depth of cracks

A method of and apparatus for measuring the layer of coating thickness of non-magnetic substances on a ferromagnetic parent material by the magneto-inductive method or of non-metallic substances on a conductive parent material by the eddy current method. This is done with the use of a probe whose coil inductance is evaluated as a criterion for the thickness of the layer to be measured. An adjustment to the geometry and the magnetic properties of the specimen are made before the first measurement. In the adjustment, at least one non-magnetic or non-conductive foil is disposed or are consecutively disposed between the probe and the surface of the coated specimen and the measured data obtained then and in the subsequent measurements are fed to a microcomputer. In the semiconductor store of the micro-computer, the non-linear relationship between the coil inductance of at least one probe and the distance between the probe and the parent material is being or has been stored in the form of at least one values table and in which the layer thickness values of the foils are being or have been stored. The microcomputer calculates the thickness values of the layer material from the measurement data fed to it and from the stored data.

Method of and apparatus for layer thickness measurement

An electrodynamic sound converter is disclosed for the non-destructive ultrasonic testing of workpieces during relative movement of the workpiece and the testing head. The testing head has an annular electromagnet which produces a magnetic field, and a rod-shaped core extends coaxially through the electromagnet and has a tip which projects beyond the same in direction towards the workpiece to be tested. The core is axially slidable relative to the electromagnet towards and away from the workpiece and the electromagnet and the tip of the core are each independently maintained at a fixed predetermined spacing from a surface of the workpiece being tested. The tip is being biased towards the surface, and a high-frequency coil is located adjacent the tip and serves to produce electromagnetic oscillations. Various modifications are also disclosed.

Growing community of inventors

Wuppertal, Germany

Volker K Deutsch