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Standard Operating Procedures (SOPs)
2.3
SASS or SuperSASS: Fit the other end of the tubing into the
individual filter's sampling inlet port. The outside diameter of the supplied
silicone tubing is just the right size to create a seal against the inside surface
of the inlet port.
2.4
Sampler with a low flow rate (1-5 lpm): You may need to adapt the
smaller inlet diameter of the downtube to accommodate a minimum 0.25"
standard barb fitting. Remove any screen that surrounds the inlet, and then
connect the inlet adapter to the other end of the supplied silicone tubing.
»
See "Standard Mode connections to air samplers via the barb fitting" on page
15 for more details.
3. Position the FP-25 external
temperature probe. Insert the temp probe
into the sampler's radiation shield, and leave
it in position during flow measurement. If the
sampler has no radiation shield, place the
temp probe in the shade in the immediate
vicinity of the sampler
Caution: The FP-25 uses its external temp probe to provide actual
volumetric flow measurements. Ensure that the temp probe is not left
in direct sunlight, where its readings can become artificially elevated.
Caution: Some samplers have metal radiation shields. Take care not to
let the tip of the FP-25 temp probe rest against this metal.
4. Prepare the air sampler. Place your air sampler into Audit or Calibration
Mode following the instructions in the sampler's manual. The sampler manual
may require you to install a new filter for this procedure.
Note: Allow the sampler’s internal flow controllers sufficient time to
warm up, as directed in the sampler’s manual. Some thermal mass
flow controllers require 15-30 minutes to achieve full accuracy.
5. Conduct the sampler's flow verification or calibration procedure.
Consult your air sampler manual for instructions.
Note: Take care to distinguish between actual (volumetric) flow rates
and standardized (mass) flow rates. In Standard Mode, volumetric flow
is displayed to the left of standardized flow at the bottom of the screen.
You can highlight either one of these values in the center of the screen
by pushing the button that lies underneath it.
5.1
Monitor live flow readings until the sampler flow rate settles.
When the FP-25 shows Instant at the top of the screen in Standard Mode,
the FP-25 is providing live flow readings. If flow is stable, you can use these
Verifying Flow Rates in Standard Mode