Why the RCA of Each Code Points to Different Contamination and Wear Mechanisms Many people look at an ISO 4406 cleanliness result such as 18/16/13 and treat it as one single number. That is a serious analytical mistake. ISO 4406 is not one value. It is three separate population indicators for three particle-size thresholds: >4 µm(c), >6 µm(c), and >14 … Continue reading Why ISO 4406 Particle Count Codes Must Be Trended Separately