The ISO 4406 particle count system has specified three size classes related to a 100 ml oil sample
as follows:
•
R
4
= number of particles equal to or larger than 4
μ
m
•
R
6
= number of particles equal to or larger than 6
μ
m
•
R
14
= number of particles equal to or larger than 14
μ
m.
The (older) NAS 1638 and SAE AS 4059 cleanliness classes for oils are given in
Cleanliness classes NAS 1638 and SAE AS 4059
.
Tab 12-6
Cleanliness classes NAS 1638 and SAE AS 4059
Number of particles per 100 ml for particle size ranges (
μ
m)
Cleanliness
class
5 to 15
15 to 25
25 to 50
50 to 100
100 to 150
(14)
4 096 000
729 600
129 600
23 040
4 096
(13)
2 048 000
364 800
64 800
11 520
2 048
12
1 024 000
182 400
32 400
5 760
1 024
11
512 000
91 200
16 200
2 880
512
10
256 000
45 600
8 100
1 440
256
9
128 000
22 800
4 050
720
128
8
64 000
11 400
2 025
360
64
7
32 000
5 700
1 012
180
32
6
16 000
2 850
506
90
16
5
8 000
1 425
253
45
8
4
4 000
712
126
22
4
3
2 000
356
63
11
2
2
1 000
178
32
6
1
1
500
89
16
3
1
0
250
44
8
2
0
00
125
22
4
1
0
X52
AA00-0000-00AAA-030F-A
Operation Manual
System oils
Winterthur Gas & Diesel Ltd.
- 449 -
Issue 002 2018-11
