The setting of the oil mirror of the nitrogen compressor is to facilitate the understanding of the remaining amount and color of the lubricating oil. Can we judge whether the equipment is malfunctioning from the color of the lubricating oil? If it is the same lubricating oil, according to the time scale trend, it is possible to analyze and judge the quality of the lubricating oil. Because the change of color means that its chemical composition has changed or there are pollutants. If it is not the same type of oil, the quality of the oil cannot be judged based on the color alone. The color of lubricating oil is related to its main raw material, and there is no direct relationship between its color and oil quality.
The color of the base oil varies according to the processing depth. Class I oils are mostly light yellow, but the II and III base oils refined through advanced hydrogenation treatment, and synthetic oils prepared by chemical methods, such as PAO, ester oils, polyethers, etc., will contain less aromatic hydrocarbons. After impurities, their color will be relatively lighter and can achieve the same transparency as water!
Influenced by additives, air compressor oils include viscosity index improvers, extreme pressure antiwear agents, antioxidants, antifoaming agents, rust inhibitors, demulsifiers, etc. All these additives have their own different colors.
When the additives and the base oil are blended, the color of the lubricating oil will have different changes, darker (such as brown), or lighter.
The effect of coloring agent, sometimes it is necessary to add a specific coloring agent to some lubricating oils and greases to change their original color. The purpose of this is sometimes to serve as a warning to distinguish other lubricants. In fact, it is more of a marketing factor. For example, Ingersoll Rand is light red, Sullair is green, Atlas is translucent white, and CompAir It is blue, Unitex is red, etc. Sometimes it is just to distinguish different product lines, and the dye will not act as a lubrication and protection.
During the use of air compressor oil, the color of the oil will change from light to dark, which is a common phenomenon. Some users directly confuse the darkening of the oil with the quality of the oil, and change the oil immediately, which is unscientific. When the air compressor oil needs to be replaced, in addition to judging from the appearance, it is also necessary to judge from the change of the comprehensive index such as viscosity, acid value and insoluble content, or roughly according to the experience of the on-site service personnel, from the consistency, odor and appearance , Preliminary judgment, sometimes the oil looks good on the outside, but it has been seriously gelled and aged. If judged from the appearance only, it is easy to cause waste of resources or ignore the real risks that actually occur.