M/E MAN ES oil filtration standards ISO 4406 Vs ISO 4407


Can someone explain the difference(s) between ISO4406 and ISO4407?
Which standard should be followed for M/E system oil filtration in electronically controlled (ME) Main Engines?

Hello @Raj.Raganathan

ISO4406 is the referenced standard by MAN. It describes how to quantify the oil cleanliness through a code that describes particle concentration per particle size.
ISO4407 and ISO11500 describe the method with which particles are counted.

Below paper is an interesting read.