Small Hole Measurement System

Military jet engine components (tail cones, augmenter liners, and turbine blades) incorporate large numbers of laser-drilled, small holes to provide surface film cooling air for protection against high operating temperatures. The holes must meet critical specifications to ensure adequate air flow while maximizing engine performance. Current inspection methods require that hole size be measured using a combination of mechanical pin gauging and flow testingtwo processes that are time consuming, require off-line testing, and are costly. Creare is developing a Small Hole Measurement System (SHMS) that provides fully automated, real-time measurement of the geometry of laser-drilled holes. During Phase I, we developed a proof-of-concept prototype and demonstrated extremely accurate characterization of the geometry of a range of both conventional and laser-drilled holes. BENEFIT: The SHMS will enable characterization of hole geometry during part manufacture. The system is expected to have commercial application in both military and private sectors for automated part inspection and measurement of critical dimensions.