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Our sampling techniques are designed to provide precise and accurate values for
aerosol parameters by size based upon a mix of well established (IMPROVE
filters, DRUM, MOUDI, and IMPROVEd DRUM) and innovative (DELTA-DRUM, 4 hr
DELTA-IMPROVE filter) sampling.
| Samplers
| 3-DRUM Sampler |
8-DRUM Sampler |
Comparisons of a Variety of Aerosol Sampling Media with
Analytical Sensitivity of Iron using PIXE, XRF and S-XRF |
DELTA-DRUM (continuously,
two matched units)
DELTA-DRUM
(intermittent, for optical sizing)
IMPROVEd DRUM
(fills gaps in DELTA-DRUM)
MOUDI, DRUM, and
IMPROVE 12 hr and 4 hr filters for Quality Assurance
The DELTA-DRUM,
an eight stage slotted-DRUM impactor designed (Raabe et al, 1988) as an 8
stage version of the 3 stage IMPROVE DELTA-DRUM/ARB MSAM
samplers proved itself successful during a study called SEAVS. This unit has several advantages over the DRUM: 10 l/min flow,
vs. 1 l/min DRUM, giving 10x the mass for analysis and better sensitivity,
6 mm slits
resulted in 3x the precision of a normal DRUM,
laterally
uniform deposits that allow beta gauge measurements of mass and development of
techniques to spectrally measure b(abs) from DRUM samples.
The DELTA-DRUM also has the
advantage of a 0.75 µm
cut in a region of high optical efficiency, based upon the results at both SEAVS
and, earlier, Los Angeles (Cahill et al). The DELTA-DRUM also handles
large input particles with a 10 µm
cyclone, which will reduce miss-sizing with giant particles poorly collected by
greased impaction stages.
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3-DRUM Sampler
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Rotating Lundgren type Impactor
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3 aerosol size cuts
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23 liters/minute
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Mylar and Aluminum substrates
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2.5 (cyclone)-1.15 um, 1.15-0.34 um, 0.34-0.1 um
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8-DRUM Sampler
See Operations Manual (ppt 2.4 mb)
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Rotating Lundgren type Impactor
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8 aerosol size cuts,10 liters/minute
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Field deployed for remote aerosol sampling on coated Mylar
substrates
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Size cuts: Inlet-5 um, 5-2.5 um, 2.5-1.15 um, 1.15-0.75 um, 0.75-0.56
um, 0.56-0.34 um, 0.34-0.26 um, 0.26-0.09 um
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Sample analysis
chamber at Lawrence Livermore National Labs, Berkeley CA. |
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DRUM Strips from Kyoto, Japan (December 1999).
The grey and black markings on the strips are particulate pollution. |
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Comparisons of a Variety of Aerosol Sampling Media with Analytical Sensitivity
of Iron using PIXE, XRF and S-XRF
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ALS |
|
Analytical Sensitivity at iron (ng/cm2) |
|
Malm et al, 1994 |
Malm et al, 1994 |
10.3.1 |
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PIXE |
XRF |
S-XRF |
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7 |
1 |
0.1 |
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ANALYSIS OF AIR SAMPLES |
Areal |
Air |
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|
Single PM 2.5 Filter Sample |
Density |
pg/m3 |
pg/m3 |
pg/m3 |
|
24 hr sample |
on filter |
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(cm2/m3) |
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Hi-Vol EPA 1970-99 |
0.26 |
1,820 |
260 |
26 |
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(TSP < 1987; PM10>
1987) |
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WINS EPA 1999 |
0.56 |
3,920 |
560 |
56 |
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Virtual Impactor EPA 1985 |
0.34 |
2,380 |
340 |
34 |
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Stacked Filter Unit UCD 1979 |
0.95 |
6,650 |
950 |
95 |
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Stacked Filter Unit UCD 1982 |
0.26 |
1,820 |
260 |
26 |
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IMPROVE UCD 1988 |
0.07 |
490 |
70 |
7 |
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Int. Aerosol Sampler UCD 1999 |
0.07 |
490 |
70 |
7 |
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ANALYSIS OF IMPACTORS |
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4 hr sample |
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Sizing, fixed or rotating drum |
cm2/m3 |
pg/m3 |
pg/m3 |
pg/m3 |
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MOUDI U. Minn. 1985 |
0.16 |
1,120 |
160 |
16 |
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DRUM UCD 1985 |
1.57 |
10,990 |
NA |
157 |
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DELTA-DRUM UCD 1998 |
0.15 |
1,050 |
NA |
15 |
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10 min sample |
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Sizing, single dot or line |
cm2/m3 |
pg/m3 |
pg/m3 |
pg/m3 |
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MOUDI U. Minn. 1985 |
NA |
NA |
NA |
NA |
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DRUM UCD (dot) 1985 |
0.013 |
1,300 |
NA |
1.3 |
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DELTA-DRUM (slot) 1998 |
0.12 |
10,000 |
NA |
12 |
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pg/m3 = picograms/cubic
meter of air, or 0.001 ng/m3 |
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