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Vickers by Danfoss Target-Pro 2 Analyzer and Sampler Operation Manual V-PP-MC-0002-E
July 2023
ISO standard 4406
is the preferred method of counting
solid contaminant particles in a sample. The code is con-
structed from the combination of three scale numbers
selected from the following table.
The first scale number
represents how many particles
in a milliliter sample of the fluid are larger than 4 µm(c).
The second number
represents how many particles are
larger than 6 µm(c).
The third number
represents how many particles are
larger than 14 µm(c).
Microscope counting
examines the particles differently
from APCs; the code is given with two scale numbers only.
These are at 5 µm and 15 µm, equivalent to the 6 µm(c) and
14 µm(c) of the APCs.
ISO 4406 Cleanliness
Code System
N U M B E R
O F
PA R T I C L E S
P E R
M L .
S C A L E
N O .
More
Up
to
and
Than
Including
2.5M
-
>
28
1.3M
2.5M
2
8
640k
1.3M
2
7
320k
640k
2
6
160k
320k
2
5
80k
160k
2
4
40k
80k
2
3
20k
40k
2
2
10k
20k
2
1
5000
10k
2
0
2500
5000
1
9
1300
2500
1
8
640
1300
1
7
320
640
1
6
160
320
1
5
80
160
1
4
40
80
1
3
20
40
1
2
10
20
1
1
5
10
1
0
2.5
5.0
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
0.0
0.01
0
Table 5: ISO 4406 Allocation of Scale Numbers
ISO 4406 Cleanliness Code Chart (with 100ml sample volume)