The Foerster CIRCOGRAPH DA is the latest generation of rotating-probe eddy current testing systems for non-destructive inspection of bright metallic semi-finished products — bars, tubes, wires, rods, billets, and rails. Rotating probe heads spin at up to 18,000 rpm around the test piece, scanning the surface in a helical pattern for 100% coverage without contact. Direct signal digitization at the sensor head minimizes analog noise pickup, and up to 256 channels are processed in real time without multiplexing — a critical advantage at high line speeds.

How does C-Scan visualization improve defect analysis?

The CIRCOGRAPH DA generates a C-Scan — a 2D map showing defect position in both longitudinal and circumferential coordinates on the test piece surface. Unlike single-channel eddy current instruments that report only a pass/fail or a single amplitude trace, the C-Scan reveals defect orientation, length, and clustering patterns. Digital speed-shift filters automatically adjust filter parameters to match the actual test velocity, maintaining consistent sensitivity across acceleration, steady-state, and deceleration phases of the production line. This is particularly valuable for wire drawing and tube production where line speed varies during coil changes.

Which rotating head matches which product size?

Four rotating heads span the full diameter range: Ro 20 covers 2–20 mm at up to 18,000 rpm (6 m/s in the F fast variant), Ro 35 handles 2–35 mm at 9,000 rpm, Ro 65 spans 5–65 mm at 6,000 rpm, and Ro 130 accommodates 10–130 mm at 3,000 rpm. The modular architecture allows a single CIRCOGRAPH DA electronics rack to serve multiple inspection stations with different rotating heads. FOERSTERnet enables remote access from multiple computer stations for centralized quality data management and ISO 9000-compliant documentation.