The test involves placing the fluid under examination in a test reservoir, where atmospheric air is maintained at 10% relative humidity. A non-rotating steel ball, held in a vertically mounted chuck, is pressed against the outside diameter of an axially mounted cylindrical steel ring with a specified load. Meanwhile, the test ring is rotated at a constant speed, partially immersed in the fluid reservoir to keep it wet and ensure continuous transport of the test fluid to the ball/ring interface. The resulting wear scar on the ball serves as a measure of the fluid's lubricating properties.