Judging the quality of vacuum diffusion pump oil can usually be evaluated by the following aspects:

Cleanliness of the pump oil: Check the color and clarity of the pump oil. High-quality vacuum diffusion pump oil should be transparent without suspended matter or sediment. Cloudiness, color changes, or impurities in the pump oil may indicate that the pump oil has deteriorated or is contaminated.

Smell of pump oil: Sniff the pump oil, if there is a noticeable pungent, sour, or peculiar smell, it may indicate that the pump oil has deteriorated or is contaminated.

Viscosity of the pump oil: Check the viscosity of the pump oil. Proper viscosity is important for proper operation of vacuum pumps. Pump oil that is too thin can cause poor seals, while too viscous can affect pump flow and performance. Use the pump manufacturer's recommended viscosity range to judge the suitability of the pump oil.

Moisture content: Moisture in the vacuum diffusion pump oil has a great influence on the performance of the vacuum system. The water content in the pump oil can be checked using a moisture analyzer or other testing methods. In general, a good pump oil should have a low water content.

Service life and maintenance intervals: Consider service life and maintenance intervals. High-quality vacuum diffusion pump oil usually has a long service life and requires less maintenance and replacement times during use.

It is worth noting that different types of vacuum diffusion pumps may have different requirements for pump oil, so it is recommended to refer to the instructions and recommendations provided by the pump manufacturer. In addition, in practical applications, it is very important to regularly check and maintain the vacuum diffusion pump and perform maintenance according to the operation manual and instructions to ensure the quality and performance of the pump oil.