Particle Count

Method Automated Laser Particle Counter
Standards ISO 4406

What is it used for?

A technique, primarily used for hydraulic oil samples, to determine the degree of particulate contamination present in a given oil sample across three specific particle size bandings.


How does it work?

A portion of sample is passed through a flow cell through which laser-light is passed en-route to a CCD sensor.


The number of “shadows” and their size determines the count of particles in the sample.


What do the results tell us?

A “code” is assigned to particle count values derived at three different micron levels: greater than 4 microns, greater than 6 microns and greater than 14 microns.


A code is generated, consisting of three numbers, e.g. 17/15/12. This would indicate that:


Particle Size Code Particles / mL
More than 4 micron 17 640-1300
More than 6 micron 15 160-320
More than 14 micron 12 20-40

This is of particular importance for hydraulic systems where small particulates can have catastrophic effects.


The technique is also a good indicator of the cleanliness of new lubricants, or the need to filter a new oil prior to use. Trending can also monitor ingress of fine particulates over time (e.g. fine wear and dust).


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