• FerroChem NDT Systems Private Limited

Flexible Copper Mesh Contact Pads for MPI

Magnetic particle inspection (MPI) is a non-destructive testing (NDT) technique for detection of surface cracks on ferrous components. In MPI, strong magnetic fields are induced in the specimen, which are being tested for cracks. The induction of strong magnetic fields is achieved by various methods; however, the most common amongst them is the "Direct Contact" method. "Direct Contact" method employ electric current of high magnitude (1000 to 3000 A) and low voltage is passed along the long axis of the specimen by gripping it between head stock and tail stock of bench type MPI equipment. The areas on the surface of the specimen, where the electric current of high magnitude enters and leaves are prone to damages due to sudden temperature rise caused by passing of the current. A "highly conductive and flexible surface" provided on head stock and tail stock enlarges the area of contact thereby limiting the temperature rise likely to be caused due to passing of high magnitude electric current. Copper mesh flexible contact pads developed by FerroChem provide the ideally expected "highly conductive and flexible surfaces". These pads are manufactured from specially developed "soft" copper braids and sheets. The surface of copper mesh snuggly enwraps the contact surfaces to increase the area of contact and minimize the rising of temperature there. These pads are "made to order" as per the sizes of head and tail stocks of the MPI equipment on which they are intended to be used. Pads with "double layer" are also available, which can be used from both the sides thus providing a longer life.