Met One Instruments LVS-100, User Manual

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Introduction MicroVol-1100 User manual 1.6
1.4 Background/ Theory
1.4.1 Particulate Sampling
The MicroVol is designed primarily as a particulate sampler. The MicroVol pump and
flow controller draws a sample of air through a specially prepared filter. The filter
collects the airborne particles for analysis. The MicroVol controls the flow-rate and
records the volume of air that has been sampled.
The airborne suspended particles are collected on a pre-weighed filter over a pre-
determined period. After the sampling period is complete, the filter is removed and re-
weighed to determine the concentration and/or composition of suspended particulate.
Concentration results are typically expressed in micrograms per cubic metre (µg/m
3
)
of air sampled at standard temperature and pressure conditions.
Acceptable levels have been established to govern the amount of airborne particulate
of a particular size and composition that may pose a health hazard to humans.
The MicroVol-1100 utilises a size-selective inlet to restrict the sampled particulate to
being that of a designated size or smaller.
•
A PM
10
sample inlet restricts the collected particulate to that with an
aerodynamic equivalent diameter (AED) of 10 microns or less.
•
A PM
2.5
sample inlet similarly restricts the collected particulate to
that with an aerodynamic equivalent diameter (AED) of 2.5 microns
or less.
•
A TSP (Total Suspended Particulate) sample inlet, ideally, samples
all suspended particulate matter. However, it should prevent
unusually large particles and insects from being collected on the
filter element.
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