ASTM D130 for oils and D4048 for greases: a polished copper strip soaks in the sample at a set temperature, commonly 100 C, then is compared with a color chart running from 1a (slight tarnish) to 4c (heavy corrosion). Active sulfur from EP additives or contamination darkens the strip. It matters for anything with bronze, brass or copper inside, such as worm wheels, bushings, coolers and windings.
Copper strip corrosion test came back 3b, that gear oil isn't going near the bronze worm wheels.
Also heard as
- copper corrosion test
- copper strip
- D130
Related terms
EP
Extreme pressure: additives or oils that react with metal under heavy load to prevent welding and scuffing.
Additive package
Pre-blended mix of performance chemicals that a blender adds to base oil to make a finished lubricant.
Oil analysis
Lab testing of in-service oil samples to judge oil condition, contamination and machine wear.
TAN
Total acid number: milligrams of potassium hydroxide needed to neutralize the acids in one gram of oil.