Filter Handling and Exchange
Pre-Sampling Filter Weighing
Thermo Fisher Scientific
Partisol 2000
i
and Partisol 2000
i
-D Instruction Manual
3-3
than ±5% relative humidity. The equilibration room must be held at a
constant temperature between 20 °C and 23 °C with a variability of not
more than ±2 °C.
Use the following procedure to weigh the 47 mm collection filters (tare
weight) before sampling. Refer to U.S. EPA 2.12
Quality Assurance
Handbook
, Section 7.
1.
Ensure that each filter has been equilibrated for at least 24 hours before
weighing.
2.
Filters must be weighed on a microbalance with a resolution of at least
1 g (0.001 mg). Be sure to warm up the balance before weighing
filters.
3.
Weigh each filter at least once (three times recommended), recording
the mass in grams (
Figure 3–1
). The average mass reading is the initial
filter weight, W
i
(g). Use appropriate techniques to neutralize static
charges on the filter. This pre-sampling weighing must take place
within 30 days of the sampling period.
4.
Immediately place each weighed filter into an open filter cassette (59-
004648-0001) (
Figure 3–2
) that has a serial number etched on the
screen. Configure the screen so that screen number is visible from
below. These filter cassettes also are referred to as having “serialized”
screens. Close the filter cassette by snapping its top part onto its bottom
section. Ensure that the top and bottom pieces of the cassette are
pushed completely together.
Figure 3–1.
Positioning a 47 mm Filter on a Balance
Pre-Sampling
Filter Weighing
