Eddy current testing is very well suited

Eddy current testing is very well suited Doctors, hospitals, and individuals depend on the highest quality hypodermic needles found to administer medicines and draw fluids. Unfortunately, 100% visual and/or water leak test inspection of the needle tubing or finished product for microscopic cracks or defects is nearly impossible. A hypodermic needle manufacturer has integrated automated eddy current testing solutions from Criterion NDT into their production lines to inspect 100% of their material for cracks and defects.

Medical grade hypodermic needles are available in numerous diameters and wall thicknesses. A hypodermic needle manufacturer wanted to detect through-wall cracks down to 0.100" x 0.004" (2.5mm x 0.1mm), in needles down to 0.011" (0.28mm) in diameter. The manufacturer’s process commences with the forming and welding of medical grade stainless steel strip, where tubing is drawn through forming dies and annealed, repeating this process until the desired diameter is achieved. The manufacturer wanted to ensure the quality of the tubing immediately prior to the needle cutting process.

Eddy current testing is very well suited for finding defects in metallic tubing and wire used for medical applications. As an example, a heart valve manufacturer employs eddy current to test the wire used in their heart valves. Manufacturers also use eddy current testing to find cracks and flaws in metal components such as bearings, gears, and shafts. Because eddy current testing is sensitive to the structure of the material, other applications may include detection of proper material hardness, case depth, and alloy. the solution In eddy current testing, an induction of an electromagnetic field into a metallic object, by way of an electrical coil, is the first step. The flow generated by the eddy currents in the metal will vary depending on the microstructure of test material. A crack or a flaw in an object will physically affect an eddy current, causing it to have to flow around the defect. The eddy current coil is sensitive to the magnetic field produced by the eddy current flow in the metal, and information related to changes in this field are processed by the eddy current instrument. The flaw detection thresholds are set based upon the enduser’s established quality requirements.