Development of computer-aided image analysis for filter debris analysis

In oil-wetted aircraft machinery fitted with coarse (>50 micron) filtration systems, sufficient fine particulate wear debris passes through the filter to enable meaningful spectrometric oil analysis (SOA) of the oil analysis (SOA) of the oil sample debris for off-line condition monitoring. The use of fine (10 micron) filters in the F404 engines of the CF-18 aircraft has severely limited the usefulness of oil analysis techniques because the filters remove almost all debris of significant from the oil. The Defense Research Establishment Pacific (DREP) has developed Filter Debris Analysis (FDA) as an alternative off-line monitoring procedure for the CF-18 F404 engines. In addition, FDA can supplement conventional oil analysis techniques for condition monitoring of machinery with coarse filtration by evaluating the accumulated wear debris generated between filter changes. The method has been very successful at predicting wear anomalies and is being adopted into the routine maintenance procedures for selected machinery. The main drawbacks of FDA at present are that it is time-consuming, it is manpower intensive, and the interpretation of debris levels is subjective. The authors are presently investigating the use of computer-aided analysis to interpret the debris found on filters with an ultimate goal of incorporating the FDA results intomore » an expert system for tracking the condition of oil-wetted equipment. Results of image capture and interpretation of FDA data are presented, and implications of these developments on condition monitoring of oil-wetted machinery are discussed.« less