“…In recent years, thanks to breakthroughs in EMT basic research such as electrostatic signal conditioning circuit design (Addabbo et al , 2015), electrostatic sensing characteristics research (Yan et al , 2021) and electrostatic signal process methods (Wang et al , 2013); some researchers have designed a variety of different electrostatic sensors for condition monitoring of aero-engine lubricating oil line, carrying out researches including fault diagnosis of accessory gearbox, rolling bearing fault diagnosis and wear monitoring (Li et al , 2020; Zhang and Wang, 2020), wear site monitoring (Liu et al , 2022a; Liu et al , 2022b) and online oil debris monitoring (Sun et al , 2021). In addition, another group of researchers have carried out research on the fault diagnosis and health monitoring of aero-engine gas path components, including the monitoring of foreign object inhalation in the aero-engine intake (Guo et al , 2022), aero-engine gas path fault diagnosis and exhaust emissions assessment (Jin et al , 2020; Guo et al , 2021a).…”