Industrial inspection of round long or continuous prod­ucts
Rev: 2002-01

General Description of the Application
For the inspection of round long or continuous prod­ucts such as wires, bars, and tubes, a traditional eddy current method uses differential encircling probes.
This is a low-cost EC solution to detect defects in the circumference of round products.
This EC solution is used for a large range of diameters typically extending from about 0.5 mm to 75 mm.
Each probe covers a range of diameters in increment between 70% and 90% of the probe diameter.
This is an excellent method to detect short defects in high-speed process in nonmagnetic and magnetic alloys. For magnetic alloys, a magnetic saturation can be operated.

Performance and Objectives of the Inspection

• High-speed inspection (10 m/s and more, depending on the size of the defects)
• Surface inspection
• Subsurface inspection: thin wall with magnetization if ferrous materials
• Defects: cracks, inclusions, holes, etc.
• Compact device

Description of the Inspection System
The product to be inspected is run through the probe and guided by a centering device to avoid lift-off variations.
The encircling probe is made with an emitter coil and two differential receiver coils.

Set of encircling probes and their mechanical support.

Parts to Inspect
• Wires in the cold or hot step of the process
• Tubes in the extrusion process
• Bars coming from lamination process

Defects to Be Detected
• Short cracks, inclusions, holes, etc.
• Examples of smallest defects:
- 0.4 mm (1/64 inc.) holes in aluminum tubes from Ø 6mm to 25 mm (0.25 in. to 1 in.)
- 0.8 mm (1/32 in.) through-wall holes in steel tubes with magnetization
- Voids in tin wire Ø 1 mm (0.04 in.)

Natural defect detected on aluminum alloy tubes.

Notes:
• The sensitivity is limited by the diameter of the products
• Differential encircling probes are not well adapted to detect long defects.
Equipment and Service
• QuickScan EC 1-1 including alarm option for paint marker, PIM21, encoder and electronic interface
• MultiView software
• Up-to-date industrial PC with at least a 17-in. monitor
• Industrial 18-in. cabinet with air conditioning
• Mechanical support
• Set of probes and centering guides adapted to the diameters
• Quadrature encoder and electronic interface (optional)
• Integration setup and test on samples
• Acceptance and training at R/D Tech Québec
• Installation and training at the customer's site

Products used for this application

QuickScan ECT
The QuickScan EC is a digital instrument designed for the inspection of ferrous and nonferrous materials using multielement probes. The capacities and flexibility of this system make it suitable for many applications such as surface inspection or measurement of material properties.