For many years there has been a requirement for the continuous monitoring of lubricating oils by a device permanently mounted on an engine or gearbox. With the advent of high temperature surface mount electronic components it is now possible to package such a device into a sensor not much larger than a standard pressure switch. Permittivity (or dielectric constant) has attracted a great deal of interest in the past as an indicator of the physical or chemical state of many solids and liquids, including lubricating oils, and dielectric spectroscopy is a standard tool in many laboratories. The challenge in making a device at the right price is to identify the best way to use permittivity, and to reduce the associated electronic circuitry to its simplest possible form. Of the two components of complex permittivity, it is shown that the imaginary part, representing the dielectric loss factor (Tang) , is the better indicator of oil quality.
On-board oil condition sensing
Ölzustandssensorik am Bord
2000
6 Seiten, 13 Bilder, 4 Quellen
Aufsatz (Konferenz)
Englisch