Let’s Talk Particle Size: Comparing ISO 23369, DFE, and Common Testing Methods

In this episode of Factory Side Chat, Scott Howard and Curt Martin dig into the details of particle size testing and what it really means for fluid cleanliness. From visual patch tests to advanced laser-based methods, they explain how to accurately measure contamination and why not all tests—and not all particles—are created equal.

You’ll learn how to interpret ISO 4406 codes, the differences between the new ISO 23369 cyclic flow test and Hy-Pro’s Dynamic Filter Efficiency (DFE) test, and why cold start retention and water/MPC testing are critical to your system’s performance and protection.