Automated liquid penetrant testing system inspects for surface defects in base metal and welds

June 14, 2010

ARC Specialties has introduced an automated approach to the final inspection process in liquid penetrant testing (LPT). The Automated Liquid Penetrant (ALP) inspection system incorporates a Cognex CCD camera with software written by the manufacturer to inspect parts for surface defects in both the base metal and welds. Defects appear as contrasting dye spots. These indications form when the penetrant wicks out of the defect into the developer.

The system identifies all relevant indications. It traces the perimeter of each indication, calculates the precise area, and gives a pass/fail grade based on user-defined tolerances set within the software. Each indication's location is recorded in a data log along with inspection data for quality records and repair work.

The PC-based system uses a GUI that allows for real-time machine vision throughout the inspection process.