Method for managing lubricant oil, and method for predicting life of lubricant oil
A management method of a lubricating oil of the invention is a method of managing a lubricating oil by determining a degradation degree of the lubricating oil containing an antioxidant, specifically, according to determination methods a and b below. The determination method a includes: measuring an infrared ray absorption spectrum of the lubricating oil using a Fourier transform infrared spectrometer; and calculating a total content of the antioxidant and an altered substance having an antioxidant function to determine a deterioration degree of the lubricating oil from the obtained content. The determination method b includes: filtrating the lubricating oil with a filter; subsequently measuring a color difference of substances captured by the filter using a colorimeter, or measuring a color difference of the lubricating oil using the colorimeter; and determining a degradation degree of the lubricating oil and a mixture degree of foreign substances based on the obtained color difference.
1. A management method of a lubricating oil, the method comprising:
determining a degradation degree of the lubricating oil comprising an antioxidant according to a determination method a and a determination method b,
wherein:
the determination method a comprises:
measuring an infrared ray absorption spectrum of the lubricating oil with a Fourier transform infrared spectrometer, and
calculating a total content of the antioxidant and an altered substance having the same functional group as the antioxidant to determine a deterioration degree of the lubricating oil from the total content; and
the determination method b comprises:
filtrating the lubricating oil with a filter,
subsequently measuring a color difference of substances captured by the filter with a colorimeter, or measuring a color difference of the lubricating oil with the colorimeter, and
determining a degradation degree of the lubricating oil and a mixture degree of foreign substances based on the color difference of the substances or the color difference of the lubricating oil.
2. The management method of the lubricating oil according to claim 1 , wherein the Fourier transform infrared spectrometer satisfies the following:
interference pattern: high-throughput Michelson interferometer;
resolution: 4 cm −1 or more; and
cell material: ZnSe.
3. The management method of the lubricating oil according to claim 1 , wherein the colorimeter is configured to measure a color difference in an RGB color space or an L*a*b* color space.
4. The management method of the lubricating oil according to claim 1 , wherein the colorimeter is configured to measure a color difference in an RGB color space.
5. A lifetime expectancy prediction method of a measurement oil by determining a degradation degree of the measurement oil in a form of a used lubricating oil comprising an antioxidant, the method comprising:
obtaining a determination value of the measurement oil according to a determination method a and a determination method b) below;
subjecting the measurement oil to a degradation process for a predetermined time until the lubricating oil reaches a threshold value representing a usage limit of the lubricating oil, and obtaining a determination value of the measurement oil after being subjected to the degradation process according to the determination method a and the determination method below; and
predicting a lifetime expectancy of the measurement oil based on a time of the degradation process in the subjecting step, the determination value, which is obtained in the subjecting step, of the measurement oil after being subjected to the degradation process, and the determination value, which is obtained in the obtaining step, of the measurement oil,
wherein:
the determination method a comprises:
measuring an infrared ray absorption spectrum of the lubricating oil with a Fourier transform infrared spectrometer, and
calculating a total content of the antioxidant and an altered substance having the same functional group as the antioxidant to determine a deterioration degree of the lubricating oil from the obtained content, and
the determination method b comprises:
filtrating the lubricating oil with a filter,
subsequently measuring a color difference of substances captured by the filter with a colorimeter, or measuring a color difference of the lubricating oil with the colorimeter, and
determining a degradation degree of the lubricating oil and a mixture degree of foreign substances based on the color difference of the substances or the color difference of the lubricating oil.