Viscosity sensors for engine oil condition monitoring-Application and interpretation of results

There is an increasing demand for the on-line condition monitoring of lubricating oils. In our recent research, we considered various sensor principles for the on-line monitoring of thermal aging of engine oils. One of the investigated parameters is the viscosity of the lubricating oil, which can be efficiently measured using microacoustic sensors. Compared to conventional viscometers, these sensors probe a different rheological domain, which needs to be considered in the interpretation of the measurement results. This specific behavior is examined by systematically investigating engine oils with and without additive packages, which were subjected to a defined artificial aging process.