A State-of-the-Art Colorimetric Patch Analyzer

摘要

In 2013, ASTM announced ASTM D7843 for analyzing oil contamination by color using commercially available colorimetric spectrometers, which use reflecting light only. Contaminants in turbine oils are mostly oil oxidation products of molecular sizes. When warm turbine oil which has been used for several years is filtered through a membrane filter, the color of the membrane filter may be white. However when the same oil is filtered after cooled at room temperature in dark for 3-4 days, the color of the membrane patch sometimes becomes brown. When we examine such an almost-white membrane patch with back light, we will notice brown color of oil oxidation products. This paper discusses a newly developed colorimetric patch analyzer to detect contaminants, which were collected on the surface, by reflecting light and also those, which were captured inside a membrane filter, by transmitting light.