Hach HIAC ROC User Manual page 26

NAS codes
Table 11 shows the original NAS 1638 contamination limits by maximum particle counts per 100 mL
of fluid or by the weight of contamination per 100 mL of fluid.
Table 11 NAS 1638 codes for maximum contamination limits
Class
00
0
1
2
3
4
5
6
7
8
9
10
11
12
1
Same as ARP598
SAE codes
Table 12 shows the SAE AS4059 codes and the cleanliness levels.
Table 12 SAE AS4059 cleanliness levels by particle count
Size, ISO 4402 calibration, or
optical microscope count
Size, ISO 11171 calibration, or
2
electron microscope
Size code
Class 000
Class 00
Class 0
Class 1
Class 2
Class 3
Class 4
Class 5
Class 6
26 English
5 to 15 µm
1,000
2,000
4,000
8,000
16,000
32,000
64,000
128,000
256,000
512,000
1,024,000
> 1 µm
1
> 4 µm(c)
A
195
390
780
1560
3120
6250
12,500
25,000
50,000
Particle size range
125
250
500
Maximum contamination limits (particles/100 mL)
> 5 µm > 15 µm
> 6 µm(c) > 14 µm(c) > 21 µm(c) > 38 µm(c) > 70 µm(c)
B C
76 14
152 27
304 54
609 109
1220 217
2430 432
4860 864
9730 1730
19,500 3460
1
15 to 25 µm
22
44
89
178
356
712
1,425
2,850
5,700
11,400
22,800
45,600
91,200
182,400
> 25 µm > 50 µm
D E
3 1
5 1
10 2
20 4
39 7
76 13
152 26
306 53
612 106
> 100 µm
F
0
0
0
1
1
2
4
8
16