www.machinerylubrication.com | September - October 2022 | 35
EXAMPLE PARTICLE COUNT
Size in
Microns
Count
Larger than
Size per ml
4 1,752
6 517
10 144
14 55
20 25
50 1.3
75 0.27
100 0.08
4µm 6µm 14µm ISO Code
1,301 321 41 18/16/13
2,500 640 80 18/16/13
2,501 641 81 19/17/14
5,000 1,300 160 19/17/14
NUMBER OF PARTICLES PER ML
RANGER
NUMBER (R)
More than Up to and Including
5,000,000 10,000,000 30
2,500,000 5,000,000 29
1,300,000 2,500,000 28
640,000 1,300,000 27
320,000 640,000 26
160,000 320,000 25
80,000 160,000 24
40,000 80,000 23
20,000 40,000 22
10,000 20,000 21
5,000 10,000 20
2,500 5,000 19
1,300 2,500 18
640 1,300 17
320 640 16
160 320 15
80 160 14
40 80 13
20 40 12
10 20 11
5 10 10
2.5 5 9
1.3 2.5 8
0.64 1.3 7
0.32 0.64 6
0.16 0.32 5
0.08 0.16 4
0.04 0.08 3
0.02 0.04 2
0.01 0.02 1
