The RULER analysis measures the residual level of antioxidants (typically amine- and phenol-based) in the oil. These substances counteract oxidation and prevent the oil from breaking down too quickly.
Using electrochemical analysis, the remaining amount of antioxidants is quantified and compared to fresh oil.
The customer gets an accurate picture of how much protection is left in the oil, and can use this to plan oil changes or assess system impact.