Measuring equipment
Particle measurement
Online particle measuring device
The separation performance of filters can be assessed by determining the number of particles in the filtrate. Various classification systems have been derived for coding the particle number, which indicate a certain particle content of a suspension in purity classes. They include, among others, the following:
- ISO 4406
- NAS 1638
- SAE AS 4059
An online particle measuring device can hence be used to ensure permanent quality control of the filter system. The specified cleanliness classes of the classification systems are based on particle size, particle number and particle size distribution.
ISO 4406 stipulates a three-digit code for the classification of the number of particles. The three classes are specified as > 4 µm, > 6 µm and > 14 µm cumulative.
NAS 1638 is the pioneer in the determination of cleanliness classes. It defines
5 cleanliness classes, with differential counting in ranges of 5 µm – 15 µm, 15 µm – 25 µm, 25 µm – 50 µm, 50 µm – 100 µm and >100 µm.
SAE AS 4059 specifies the particle count cumulatively for ranges of > 4 µm, > 6 µm,
> 14 µm, > 21 µm, > 38 µm and > 70 µm.
Request particle measurement