Lubricants Impedance analysis

The impedance analysis can be further refined by looking at the modulus representation of the bulk lubricant response. The modulus spectrum sometimes allows determining an additional MHz range relaxation with characteristic capacitance of 20pF/cm and resistance in high ohms to low kohms in "model lubricant systems" with abnormally large excesses (15 to 20 percent) of polar additive [19]. This MHz featiue was identified as orientational... 

An equivalent-circuit model describing the impedance response of a typical lubricant has to take into account processes divided spatially into bulk lubricant and interfacial electrochemical (adsorption, mass transport, and charge transfer) zones [6]. Separation between these two zones can be achieved following the distributed impedance analysis in Section 6-3. The bulk resistance BULK represents a lossy part of the overall bulk-media relaxation mechanism [3,4], always existing in parallel with a bulk-media capacitance as ... 

V. F. Lvovich, M. F. Smiechowski, Non-linear impedance analysis of industrial lubricants, Electrochim. Acta, 2008,53, pp. 7375-7385. 

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