The best test to see if your oil is contaminated is through a micron gauge.
Viscosity is a measure of the weight of the oil.
Black Gold vacuum pump oil is an ISO 41, special to this type of application.

Technical Details

Product Details

Product Dimensions

Package Dimensions
Width : 6.9 inch
Height : 3.6 inch
Length : 9.9 inch

Item Weight: 0 ounce (View shipping rates and policies)
Shipping Weight: 1.9 pounds (View shipping rates and policies)

ASIN : B003ZZFL10