Application Testing for concealed cracks in bolted connections with thick walls The ARK 31-2 is a toroidal core probe in an absolute circuit. It is designed for low-frequency tasks in the range from 30 Hz to 5 kHz. Its ring-shaped, focused eddy current field makes it less sensitive to interference from iron bolts or iron rivets. Its high penetration depth enables it to identify cracks in aluminum at depths of up to 10 mm. The signal image above shows the crack between two bores at a depth of 6 mm in the medium layer of a bolted connection. To do so, the probe is positioned above the head of the ferritic bolted connection. The signal in the middle of the image shows a non-defective connection, while the signal above it is the crack. A test piece with a defined defect is required in order to adjust the device parameter settings. ARK 31-2 absolute probe Application: Crack detection in multi-layered bolted or riveted sheets. Low interference from iron bolts and rivets due to the focused, ring-shaped eddy current field. Probe system: Absolute ferrite core, transformer-like Frequency range: 30 Hz - 5 kHz Active range: Depending upon the diameter Penetration depth: Approx. 4 - 10 mm (depending upon the diameter) Technical data Cable: EK-X-HF Housing: Plastic (Delrin), stainless steel Diameter: 8 - 26 mm Weight: 30 - 50 g Order data: A00xxxx6 (Please inform us about the diameter) www.rohmann.de • E-Mail: info@