Remaining Useful Life Estimation Routine (RULER) uses Linear Sweep Voltammetry to measure the levels of Amine and Phenol anti-oxidant additives in the oil. These are typically compared with a baseline measurement obtained from a virgin oil sample (ideally from the same batch of oil).
If anti-oxidants are allowed to deplete below a critical level the oxidation process accelerates, leading to reduced oil life and potential for varnish deposition. RULER monitoring enables management of the additive levels through top up or partial changes, significantly extending the life of the oil.