Varian rough pump oil level

[Jsup]

There's an ongoing debate in the lab as to the proper fill level for oil in our Varian HS 602 rough pumps. I had heard filling roughly half way up the viewing window was protocol and techie X has heard filling it to the top line is protocol. Does anyone have any experience with proper oil filling?

[Rick]

The upper line indicate the maximum level permits for oil.
The best level is 3/4 between the minimum and maximum level.