A Planar Inductive Based Oil Debris Sensor Plug

• Published in: 2019 13th International Conference on Sensing Technology (ICST) pp. 1 - 4
• Main Authors: P., Muthuvel, George, Boby, Ramadass, G.A.
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01.12.2019
• Subjects: Condition Monitoring; Hydraulic oil; Inductance-to-Digital Converter; Inductive Coil; Lubrication oil; Online sensor; Wear debris
• ISSN: 2156-8073
• DOI: 10.1109/ICST46873.2019.9047688

Online monitoring of debris in hydraulic and lubrication oil is an effective method to enable preventive maintenance of the associated machinery. The debris particles generated by the machinery due to wear and tear are carried by the working or lubrication fluids. This paper presents a new online magneto-inductive sensor plug. The new sensor plug consists of a permanent magnet (PM) and a spiral-shaped planar sensor coil. The static magnetic field of the PM is utilized to attract the ferrous wear debris particles, that reach the oil tank/reservoir, to the sensor coil. The inductance of the sensor coil placed close to the PM will change as a function of the presence of magnetic/conductive debris. The change in inductance is measured using a high-resolution inductance to digital converter. The prototype of the proposed sensor unit is tested in an experimental setup similar to an industrial hydraulic system. The sensor responses for different size and quantities of debris particles were recorded after injecting them into the hydraulic circuit. The particles that are attracted towards the sensor plug are retained in the plug itself. Hence its recirculation in the machinery is avoided.