In the meantime, we developed an own Integrated Sensors Board (ISB) in combination with commercially available ultrasound (>20kHz) sensitive MEMS sensors, supposed to be used in deployed cooled IR imager platforms, especially used for 24/7 continuous surveillance applications. We report on the specific electronic signal and data processing design and layout of our sensors board solution, where an effective data reduction and further analysis is applied down to calculation of relevant lifetime and state of wear figures for the definition of an effective lifetime model of the cooler mechanics, especially the bearings used on the coolers compressor. As part of RICOR’s goals to add the ability of failure prediction to its coolers, for improving customer’s Life Cycle Cost (LCC) , tests were performed with the ISB. First test results based on accelerated endurance lifetime tests performed at RICOR test facility on rotary Stirling coolers are reported and show a clear and robust indication of relevant state of wear figures, that can be used as end lifetime parameters, enabling effective alert to perform preventive maintenance. We clearly differentiate the herein reported methodology from frequently reported attempts based on vibrational analysis in the acoustic regime, where a strong dependence on the structural built-in conditions and the surrounding mechanics can make the clear indication of increasing wear induced damage inside the cooler mechanics, especially the bearings, almost impossible. |
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