What is a lux test for used oil?

A lux test for used oil measures the oil's ability to transmit light, indicating its clarity and contamination levels. The test involves shining a light through a sample of the oil and assessing the amount of light that passes through. Higher levels of contamination, such as soot or particulate matter, will reduce light transmission, signaling a need for oil change or further analysis. This test is useful for determining the oil's condition and effectiveness in lubrication.