SBIR-STTR Award

The ultimate goal of this three phase SBIR proposal is to design, develop, fabricate, and test real- time radiography system for inspecting large CDI castings with the emphasis on the production oriented inspection system. The proposed system takes significant advantage of detector system, data acquisition system, automated data analysis and image display software already developed by Omega. The propose designs are based on Omega's unique and very high performance detector designs and the Tangential Scanning technique developed for the NSWC Tangential Scanner System for Rocket Motors. The Tangential data collection method has already proven it's advantages in the Rocket Motor System. It leads to faster scanning rate, smaller data files, larger contrast due to flaws and easier yet faster data analysis. The Tangential scanning technique will use the natural circular symmetry of the CDI casting for data collection. In the Tangential Scanner system, the data is naturally collected at the tangent of various diameter circles. Thus the data is naturally collected through equal amount of steel material. This leads to mostly equal x-ray signal detected by the detector system. In such a scanning scheme, abrupt or even slow change in the x-ray intensity is easy to recognize. The difference in the detected x-ray intensity is usually either due to a flaw or a known feature in the casting. Simple image analysis techniques like Thresholding, Differentiation, Low Order Curve Fitting, Mask Subtraction and other Convolutions can be used in automated mode to detect flaws and unwanted features in the CDI castings.

The goal of the 3 phase program is to build and test a RTR system for large CDI castings with production use emphasis. This system takes advantage of detectors, data acquisition hardware, automated data analysis and image display software already developed by Omega. The phase II prototype is based on improvements in the detector system built during phase I. During phase I, we fabricated a test set up to scan 5

Benefit:
The Tangential system for CDI casting will provide a very powerful tool for the Navy's CDI casting program. Similar problems and applications exist in the commercial world (automotive, machine tool and large equipment industries) where CDI castings are used.

Keywords:
scanning, radiography, Tangential