Met One Instruments LVS-100, Руководство пользователя

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Installation MicroVol-1100 User manual 1.6
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Stretched Teflon filters
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Quartz glass-fibre filters
•
Fluoropore filters
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Membra-fil filters
Select the type of filter that is most suitable for the particles that you are interested in
sampling, but do not use filters that are, or become, too restrictive, or the sampler will
be unable to maintain constant flow-rates. Filters with a sealing-ring around the outer
edge are recommended.
The filters should only be handled with clean, non-serrated tweezers, never with
fingers, and only at the edge.
Inspect each filter for defects such as pinholes, loose material, discolouration and non-
uniformity. Discard any filters that are defective in any way.
2.6.1 Pre-collection equilibration
Place filters on a Petri dish, and label each dish with a filter number. The
filters need to equilibrate for at least 24 hours under precisely controlled
temperature and relative humidity conditions:
Relative humidity should be maintained at a constant level of 50%
±
10% with
a variability of less than 5% (Australian Standards 3580.9.6-1990)
Temperature should be maintained at a constant level of 20-25
°
C (Australian
Standards 3580.9.6-1990).
A 6-place microbalance with a resolution of better than 0.01mg is required.
Before initial weighing of the filters, turn the microbalance on for 1 hour to
allow them to stabilise.
Weigh each filter at least twice and record the average initial mass of each
filter, W
i
. Always check the zero reading of the microbalance between each
reading.
Immediately after weighing, place each filter into either a filter holder, and
assemble the filter holder, or into a Petri dish with a lid. The sample travels
down through the filter holder, so ensure that the filter is installed with the
sample side up.
Record the relative humidity, temperature, date and time of the initial
weighing.
2.6.2 Filter exchange
Filter element exchange should ideally occur under laboratory conditions. Two
or more filter holders can be used on a rotating basis. Extra filter holders are
available as spare parts. Transport the filter holder (filter element installed) in
a press-seal anti-static plastic bag to the sampling site.
Whenever a filter is replaced, record the time, date, sampling times and dates.
This may be a good time to record the sample volume and corrected sample
volume, or download the data from the MicroVol. (See section 5)
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