Rohmann – ultra fast sorting
23 February 2015
The demand on automatic inspection equipment for the 100% inspection of screws, nuts, stamped parts and fastening components is constantly increasing. Beside the capability of cross-checking material properties (such as hardness, tensile strength or other important material characteristics) or geometric deviations, inspection speed is a very important factor.
Taking this into account, Rohmann GmbH with its head office in Frankenthal, Germany, has developed a special user mode for its Elotest PL500 and Elotest IS500 instrument series.
FastSort – ultra-fast single frequency sorting with inversion point determination
The FastSort operating mode is used for structural or material verification testing on a fast moving test piece, with encircling absolute coils or absolute touch probes. In contrast to multi-frequency sorting it is not necessary to stop the test piece at the sensor. In FastSort mode the inversion point of the XY signal is determined, corresponding to the optimal placement of the test piece in the test coil or near the touch probe. Only this inversion point is evaluated and compared with the evaluation thresholds. In this way, each test piece is tested in a reproducible position. If set up correctly, the test is, as far as possible, independent of the speed of an individual part (number of parts per time interval).
To trigger the determination, the instrument itself creates a detection threshold, which is also taken to count the number of pieces. The only requirement is that the pieces are fed with a significant separation. Inspection speeds of up to 200 parts/second can be achieved, depending on the handling mechanics used. Finally the FastSort mode is not dependant on a certain frequency range, so the test frequency can be freely chosen to optimise the required inspection result.
Additional to the FastSort mode, Rohmann GmbH provides a selection of suitable coils and touch probes. One is the HDS (High Distance Sensor) PLA-61. This sensor was designed for ‘glass plate’ applications, where the test pieces are placed on a fast rotating glass plate. The sensor is placed under the glass plate, and works even with a distance of up to 10mm to the test piece. If required the sensor can also be installed beside or above the test parts.
www.rohmann.de
