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Vickers by Danfoss Target-Pro 2 Analyzer and Sampler Operation Manual V-PP-MC-0002-E
July 2023
Ta r g e t C l e a n l i n e s s L e v e l s
You can use cleanliness levels to establish bench-
marks. If you have no component failures over a
prolonged testing period, the average level meas-
ured during that time may be an acceptable goal. If
you need to reduce equipment failures, want to
increase component life, or expect conditions to
change considerably, you can establish a higher
benchmark and use testing to help reach it.
An acceptable level of cleanliness depends on
three features:
1.
the contamination sensitivity of
components;
2
. the operational conditions of the
system;
3.
and the required reliability and life
expectancy.
NAS [National Aerospace Standard] 1638 Cleanliness Code System
Maximum Contamination Limits
(per 100 ml)
Size Range Classes (in microns)
00
0
1
2
3
4
5
6
7
8
9
10
11
12
5–15
125
250
500
1000
2000
4000
8000
16000
32000
64000
128000 256000
512000
1024000
15–25
22
44
89
178
356
712
1425
2850
5700
11400
22800
45600
91200
182400
25–50
4
8
16
32
63
126
253
506
1012
2025
4050
8100
16200
32400
50–100
1
2
3
6
11
22
45
90
180
360
720
1440
2880
5760
Over 100 0
0
1
1
2
4
8
16
32
64
128
256
512
1024
Cleanliness Code Chart (with 100mL sample volume)
H y d r a u l i c C o m p o n e n t M a n u f a c t u r e r s ’
R e c o m m e n d a t i o n s
Manufacturers know the effects of contamination. They issue
maximum permissible contamination levels, and
remind users that cleaner fluids will improve performance
and increase component life. But no one has established a
single standard for the cleanliness of hydraulic fluid, in part
because working conditions are different for any two appli-
cations. As a result, even trusted sources of information on
cleanliness levels give varying recommendations.
The table below should help you get started. It gives a
selection of maximum contamination levels that aretypical-
ly issued by component manufacturers. These relate to the
use of the correct viscosity mineral fluid. An even cleaner
level may be needed if the operation is severe, such as high
frequency fluctuations in loading, high temperature or high
failure risk.
Note:
The recommendations in this table should be viewed as
starting levels; adjust them as needed to reflect opera-
tional experiences or user requirements.
U N I T
T Y P E
I S O 4 4 0 6 C O D E
Pump
Piston (slow speed, in-line)
2 2 / 2 0 / 1 6
Piston (high speed, variable)
1 7 / 1 5 / 1 3
Gear
1 9 / 1 7 / 1 5
Vane
18/16/14
Motor
Axial piston
18/16/13
Radial piston
19/17/13
Gear
20/18/15
Vane
19/17/14
Valve
Directional (solenoid)
20/18/15
Pressure control (modulating)
19/17/14
Flow control
19/17/14
Check valve
20/18/15
Cartridge valve
20/18/15
Proportional
18/16/13
Servo valve
16/14/11
Actuator
20/18/15
Typical Manufacturer Recommendations for Component Cleanliness (ISO 4406)
The NAS system was developed in 1964 to define classes
of contamination in aircraft components.This standard was
extended to industrial hydraulic systems simply because
nothing else existed at the time.
The coding system defines the maximum numbers permit-
ted of 100ml volume at various size intervals (differential
counts) rather than using cumulative counts as in ISO 4406.
Although the standard provides no guidance for quoting lev-
els, most industrial users quote the highest code recorded
in all sizes; this convention is used on the Target-Pro 2.
Contamination Level Classes according to NAS 1638
(January 1964)
Each contamination class is defined by a number from 00 to
12 that indicates the maximum particles per 100 ml, counted
on a differential basis, in a given size bracket.
Contamination
Correspondent Recommended Typical
Codes
Codes
Filtration
Applications
ISO4406
NAS1638
Degree
4µm(c) 6µm(c) 14µm(c)
Bx
≥
200
14
12
9
3
3
High precision and
laboratory servo-systems
17
15
11
6
3–6
Robotic and
servo-systems
18
16
13
7
10–12
Very sensitive–high
reliability systems
20
18
14
9
12–15
Sensitive–reliable systems
21
19
16
10
15–25
General equipment
of limited reliability
23
21
18
12
25–40
Low-pressure equipment
not in continuous service
