Determining The Starting Weight; Determining Sampling Points / Affixing The Magnetic Disk; Sampling - Wohler DTEST Notice D'utilisation

Dust surface density / level of cleanliness in air ducts and air-guiding surfaces
4.2 Determining the start-
ing weight
Fig. 8: Test canister
4.3 Determining sampling
points /
affixing the magnetic
disk
4.4

Sampling

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Place a single test cloth in each of the respec-
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tive test canisters, before moistening it with
solvent.
Use the scales to determine the weight of the
•
test canister.
Use the marker pen to write the starting
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weight on each test canister.
Determine the points where samples are to be
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taken and obtain access.
To facilitate sampling, affix the magnetic disk
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at the previously determined positions one af-
ter the other.
NOTE!
Use sufficient solvent in particular when it is
not possible to gather enough dust and dirt for
sampling, for example oily or old deposits of
soiling.
Select a suitable solvent. Isopropyl alcohol
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and acetone are suitable for metallic surfaces.
CAUTION!
Acetone can damage plastic materials. If neces-
sary, check resistance lists of the surface material
where the sample is to be taken!
Apply either small amounts of solvent to the
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respective test cloth or more to a larger area
of the cloth depending on the level of soiling.
Collect all dust/soiling on the inner surface of
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