Method for on-line monitoring of lubricating oil using light in the visible and near IR spectra

摘要

Oil aging and particulate building in a lubricant other than one exposed to combustion products is monitored by detecting light transmitted through the lubricant at least one, and preferably, two or more preselected wavelengths over a pathlength greater than about 0.5 cm wherein one wavelength is in the near infra-red spectrum and/or one wavelength is in the visible or near infra-red spectrum. The detected light when compared to predetermined values provides an indication of the condition of the lubricant.