Appendix
Note: increasing the measurement reference by 1 causes the particle count
to double.
Example: ISO code 18 / 15 / 11 means:
Cleanliness class
Particle count / 100 ml
Size ranges
18
130,000 – 250,000
> 4 µm
(c)
15
16,000 – 32,000
> 6 µm
(c)
11
1,000 – 2,000
> 14 µm
(c)
are found in 100 ml of an analyzed sample.
Overview of the differences between ISO 4406:1987 and ISO 4406:1999
"old" ISO 4406:1987
"new" ISO 4406:1999
Size ranges
> 5 µm
> 15 µm
> 4 µm
(c)
> 6 µm
(c)
> 14 µm
(c)
Dimension
determined
Longest dimension of
a particle
Diameter of the
coextensive circle
ISO 11171:1999
Test dust
ACFTD - dust
1-10 µm ultra
fine fraction
ISO 12103-1A1
SAE Fine,
AC – Fine
ISO 12103-1A2
SAE 5-80 µm
ISO MTD
Calibration
dust for
particle
counters
ISO 12103-1A3
SAE Coarse
Coarse
fraction
ISO 12103-1A4
Comparable size
ranges
Old ACFTD
calibration
Comparable
ACFTD
calibration
New NIST
calibration
-----
< 1 µm
4 µm
(c)
5 µm
4.3 µm
6 µm
(c)
15 µm
15.5 µm
14 µm
(c)
FCU 2000-4 series
en(us)
109 / 120
BEWA FCU2000-4 3109987h en-us 2017-01-24.docx
2017-01-24
