Black gold vacuum pump oil is an ISO 41, special to this type of application
For use in any vacuum pump, black gold is extremely pure and non-detergent
Black gold is hydro processed which means it goes through a series of catalytic steps rendering the oil extremely refined, more viscous and more stable
Result is clear mineral oil which will alert to contamination sooner as it becomes cloudy or milky
In extreme temperatures, the oil will be more resistant to contaminants
Oil be changed after every evacuation for maximum performance and pump efficiency
Best test to see oil is contaminated is through a micron gauge, with a leak free system
Viscosity is a measure of the weight of the oil
For industrial oil, the viscosity is an ISO grading at 40 deg C