Filtertechnik
1 Central Park, Lenton Lane, Nottingham, NG7 2NR
Tel:
+44 (0)115 9003 600
Email:
Fax:
+44 (0)115 986 8875
Registered in England No: 03969985 VAT No: 760 821 731
Certification No. UK002838
Page 13 of 15
NAS Codes (NAS 1638)
Class
Particle Size Range (Particles/100 mL)
5 to 15 µm
15 to 25 µm
00
125
22
0
250
44
1
500
89
2
1,000
178
3
2,000
356
4
4,000
712
5
8,000
1,425
6
16,000
2,850
7
32,000
5,700
8
64,000
11,400
9
128,000
22,800
10
256,000
45,600
11
512,000
91,200
12
1,024,000
182,400
SAE Codes (SAE AS4059)
Maximum Contamination Limits (Particles/100 mL)
Size, ISO 4402
calibration, or optical
microscope count
1
> 1 µm
> 5 µm
> 15 µm
> 25 µm
> 50 µm
> 100 µm
Size, ISO 11171
calibration, or electron
microscope
2
> 4 µm(c)
> 6 µm(c)
> 14
µm(c)
> 21
µm(c)
> 38
µm(c)
> 70
µm(c)
Size Code
A
B
C
D
E
F
Class 000
195
76
14
3
1
0
Class 00
390
152
27
5
1
0
Class 0
780
304
54
10
2
0
Class 1
1560
609
109
20
4
1
Class 2
3120
1220
217
39
7
1
Class 3
6250
2430
432
76
13
2
Class 4
12,500
4860
864
152
26
4
Class 5
25,000
9730
1730
306
53
8
Class 6
50,000
19,500
3460
612
106
16
Class 7
100,000
38,900
6920
1220
212
32
Class 8
200,000
77,900
13,900
2450
424
64
Class 9
400,000
156,000
27,700
4900
848
128
Class 10
800,000
311,000
55,400
9800
1700
256
Class 11
1,600,000 623,000
111,000
19,600
3390
512
Class 12
3,200,000 1,250,000 222,000
39,200
6780
1020
1
Particle size based on the longest dimension.
2
Particle size based on the projected area equivalent diameter.
