Filter Handling and Exchange
Computation of Mass Concentration
Thermo Fisher Scientific
Partisol 2000
i
and Partisol 2000
i
-D Instruction Manual
3-11
8.
Determine the net mass filter loading (DW) by subtracting the average
initial filter weight (W
i
computed in Step 3 of “
Pre-Sampling Filter
Weighing
” on page
3-3
) from the final filter weight (W
f
computed in
Step 4 above). Ensure that the figures used in this computation were
obtained from the same filter and balance.
Figure 3–10.
Placing a Used 47 mm Filter on a Balance
Note
Refer to the U.S. EPA 2.12
Quality Assurance Handbook
, Section
11.
▲
Compute the average mass concentration (MC) of particulate matter
during the sampling period using the following formula with the
information previously assembled:
where:
DW = the net change in the mass (g) of the 47 mm filter between
the initial weighing and the post-collection weighing, as computed
in Step 8 of “
Post Collection Weighing
”.
10
6
= Conversion factor from grams (g) to micrograms (μg).
V = the volume drawn through the filter, as obtained from the
Sampler. For U.S. EPA PM
2.5
, this must be volumetric m³. Other
sampling standards require that the standard volume be used. The
Partisol 2000
i
and Partisol 2000
i
-D Samplers report volumes in
both the actual or standard volume.
For 24-hour PM
2.5
concentration averages to be valid without adjustment
for U.S. EPA reporting purposes, the total sampling time must be between
23 and 25 hours, and other requirements must also be met, as referenced in
the U.S. EPA 2.12
Quality Assurance Handbook
, Section 8. The Sampler
Computation of Mass
Concentration
