ISO 4406: Particulate Contamination, by HIAC Particle Counter, ISO Cleanliness Code

ISO 4406 Hydraulic Fluid Power Fluids-Method for Coding the Level of Contamination by Solid Particles

Hydraulic systems use pressurized hydraulic fluids to transmit power. Contamination of these fluids, from environmental debris, microbial growth, wear, fluid degradation or other sources, may decrease system efficiency, damage components and potentially cause system failure. The ISO Cleanliness Code is a standardized system developed to give a comparative value of the number of particles in a fluid. In this method, the concentration of particles in 3 size categories (? 4 µm, ? 6 µm and ?14 µm) is determined and used to establish the ISO Cleanliness Code rating.

Using an Automatic Optical Particle Counter as per the method, the number of particles in each size category is determined and reported along with the ISO Cleanliness Code.

Related tests offered by Petro-Lube: We offer optical microscopy tests (ARP 598B, WQTM 611, ASTM F312, FTM 3013, FTM-3009) and Automatic Optical Particle Counting (ISO 4406, ASTM D6786, FTM 3012, SAE J1165, SAE 749) to determine the cleanliness of fluids. Automatic optical particle counting is the best choice for most samples it usually yields accurate results and gives an in-depth breakdown of particle sizes in the sample. Optical microscopy helps to identify the types of particles in cases of high automatic particle counts. If you are interested in the total volume of sediment consider ASTM D2273, FTM 3101 or ASTM D91. For the total mass of particles by filtration, consider ASTM D4898.

We offer three types of automatic particle counting tests: (1) ISO 4406, presently the most commonly used code to express the cleanliness of hydraulic fluids. (2) the ISO Solid Contaminant Code (SAE J1165) and (3) the National Aerospace Standard Code (NAS 1638).