An instrument for assessing metallic wear debris captured by filter patch or magnetic chip detector

A prototype instrument has been developed that enables the quantification of significant metallic wear debris captured on either a filter patch (also known as a porous membrane) or a magnetic chip detector. With the introduction of fine filtration to machinery lubrication systems, the effectiveness of traditional oil analysis methods such as Spectrometric Oil Analysis (SOA) is significantly reduced, often to the point where it ceases to provide useful information about machinery health. The filter element in a lubrication system is a rich source of machinery health information however it is not often considered or exploited for condition monitoring. Whilst the filter patch technique is a convenient way for extracting the debris from a filter element, analysis of the captured debris has traditionally been tedious, time consuming and can lack repeatability. Other methods do exist to quantify filter debris, however they typically involve the transportation of the entire filter element to a laboratory, which is not always practical. The instrument that has been developed enables the metallic content of a filter patch to be quantified for trending or to identify which filter patches require further detailed examination. The instrument has also been designed to liberate and quantify ferromagnetic debris captured on a magnetic chip detector. Magnetic chip detectors are used widely in aviation machinery, however the assessment of captured debris is generally limited to a periodic visual inspection. The instrument uses a unique method to liberate and recover the debris combined with a commercially available inductive wear debris sensor.