Closed mesh filters are the finest fabric possible. No measurable pore size |
Different binding (1 µm, 5µm, 10µm Mesh Filter) in Filtration Tests
Fabric: Sefar 03-1/1 ("1µm") |
Fabric: Sefar 03-5/1 ("5µm") |
Fabric: Sefar 03-10/2 ("10µm") |
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Test Setup scematically |
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The
filtrationtests were done by 5 different operators in the same way.
First the blank value of the equipment was determined. Then
the test liquid was filtered by a so-called 1µm mesh filter.
After that the filter was dried and archived in a filtermount. The
analysis of this filter (Dirt Liquid) showed the number of particles
which was hold back.
After that the filtered liquid (which passed the 1µm filter) was filtered with a 0.8µm Cellulose filter. The analysis of this 0.8µm filter (Filtered) showed the number of particles which could pass the mesh filter.
The
procedure was carried out also with the so-called 5µm and 10µm
filter as well as with an 15µm (open mesh) filter.
All
analysis were carried out with a pixel resolution of 2.3µm/px.
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Particle
number in size range 5 - 15 µm (rounded):
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Blank |
"1µm" |
"5µm" |
"10µm" |
15 µm |
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Dirt |
Filtered |
Dirt |
Filtered |
Dirt |
Filtered |
Dirt |
Filtered |
Min |
1.700 |
26.000 |
61.000 |
24.000 |
59.000 |
40.000 |
63.000 |
20.000 |
56.000 |
Max |
4.100 |
43.000 |
80.000 |
52.000 |
83.000 |
46.000 |
80.000 |
44.000 |
117.000 |
Average |
2.500 |
33.000 |
70.000 |
39.000 |
69.000 |
42.000 |
74.000 |
29.000 |
86.000 |
All
closed mesh filters showed the same result in the filtration test
within the accuracy of this test setup.
The assignment 1µm,
5µm, 10µm is misleading, because it suggests a true pore
size. All these fabrics do not have "true" pores.
They
are closed mesh filters and the so-called 1µm filter holds
back the same number of 5-15µm partices as it allows to pass
through.