The challenge: Many of these defects are hidden inside the material or at transition points. Visual detection is generally not possible in a reliable manner. 

Non-destructive testing during operation 

Modern, non-destructive material testing in a continuous process is therefore indispensable — especially for detecting mechanical inclusions and other undesirable phenomena such as pores, cavities, or grooves. The eddy current-based testing and detection system from ROLAND Electronic, the UFD 40, was specially designed for continuous industrial use in wire and cable plants.

Real-time measurement using the eddy current method

The measuring principle is based on the eddy current measurement method. First, a magnetic field is generated by a coil. Then, eddy currents are induced in the test object, a conductive material (e.g., wire or cable). Material defects, such as flaws or bonds, alter the flow of these eddy currents. This leads to measurable changes in the magnetic field of the receiver coil. These changes are recorded, filtered, and analyzed by the evaluation electronics. A change is then recognized as a “defect” if the filtered sensor signal exceeds the predefined switching threshold. This is done in a continuous process, contactless, and in real time. The maximum sampling rate for the measurement is 15 kHz. This enables the system to achieve a position resolution of 0.6 mm at material speeds of 10 m/s. The self-sufficient measuring box transmits the measurement result directly to the PLC of the entire system via a fieldbus network or parallel I/O. With the “error” information and the precise position data, the appropriate measures can be taken to rectify the error. 
 

Wide range of uses thanks to modular design

The UFD 40 test coil system has a modular design and is suitable for material diameters from 1 to 90 mm as standard (larger diameters are also possible). The different sensors for the respective test piece diameters can be exchanged quickly and easily. The UFD 40 is multi-channel capable. Each channel has completely independent functionality (measurement, evaluation, and real-time communication with the PLC). The channels either operate autonomously in “standalone” mode or are controlled by an external PC (“remote” mode). 
 

The UFD40 from ROLAND ELECTRONIC is a powerful eddy current testing system for wire and cable manufacturers that can be easily and seamlessly integrated into existing production lines. It reliably detects mechanical defects and other faults during operation, thereby significantly reducing costly rejects in production, fully automatically.

Link:
https://umformtechnik.net/wire/Content/Reports/Precise-splice-detection