The presence of pentane insolubles loosely shows the degree of sludgy residue formed by oxidative degradation. This degredation can include lubricants, wear debris, soot from fuel combustion, and other ingress particles.
Toluene insoluble materials typically originate from external contamination, degradation of fuels and oils (and their additives), or wear debris and corrosion products.
In short, the insolubles are separated from the lubricant itself and gravimetrically measured.
Results give an indication of the lubricant’s ability for form resinous matter, or to determine the presence of debris and soot that may lead to additional machine issues.
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