SAE ARP598 and ISO 4407 Compliant Technological Advances in Wear Debris Particle Imaging for On-Site Condition Monitoring in the Aerospace Industry

The need to maintain aircraft in remote, harsh environments poses significant challenges. For example, in desert assignments or on-board carrier vessels where frequent rotation of staff with variable levels of skill and experience requires condition monitoring equipment that is not only robust and portable but also user friendly and requiring a minimum of training and skill to set up and use correctly. The mainstays of any on-site aircraft maintenance program are various fluid and particulate condition monitoring tests that convey information about the current mechanical state of the system. In the front line of these is the collection and analysis of wear debris particles retrieved from a component’s lubricating or power transmission fluid or from magnetic plugs. It is standard practice within the specialist laboratory environment to view and image wear debris using a microscope. However, it is not possible to view both macroscopic and microscopic particles at the same magnification. In addition, shallow depth of focus at high magnifications means that microscope stands must be particularly stable in order to view and capture blur-free images. Thus, a good quality microscope will weigh upwards of 20kgs.The current work has researched and developed new imaging technology that caters specifically to the need for robust, portable imaging equipment that is easy to set up and use on-site. The novel hardware/software combination is ISO 4407, SAE ARP598 and ASTM D7684 compliant with a range of on-screen magnifications from x20 to x500 and produces sharply focused one-shot images that allow both macroscopic and microscopic particles to imaged and analysed at the same magnification.