The DELTA Group

for the Detection and Evaluation of the Long-Range Transport of Aerosols









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Technology

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 |

 

Samplers

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 m 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 m cyclone, which will reduce miss-sizing with giant particles poorly collected by greased impaction stages.

3-DRUM Sampler

  • Rotating Lundgren type Impactor

  • 3 aerosol size cuts

  • 23 liters/minute

  • Mylar and Aluminum substrates

  • 2.5 (cyclone)-1.15 um, 1.15-0.34 um, 0.34-0.1 um

 

8-DRUM Sampler  

See Operations Manual (ppt 2.4 mb)

  • Rotating Lundgren type Impactor

  • 8 aerosol size cuts,10 liters/minute

  • Field deployed for remote aerosol sampling on coated Mylar substrates

  • 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

 

Sample analysis chamber at Lawrence Livermore National Labs, Berkeley CA.

 

DRUM Strips from Kyoto, Japan (December 1999). The grey and black markings on the strips are particulate pollution.

 

Comparisons of a Variety of Aerosol Sampling Media with Analytical Sensitivity of Iron using PIXE, XRF and S-XRF

 

 

 

 

ALS

Analytical Sensitivity at iron  (ng/cm2)

 

Malm et al, 1994

Malm et al, 1994

10.3.1

 

 

PIXE

XRF

S-XRF

 

 

7

1

0.1

 

 

 

 

 

ANALYSIS OF AIR SAMPLES 

Areal

Air

 

 

Single PM 2.5 Filter Sample

Density

pg/m3

pg/m3

pg/m3

24 hr sample

on filter

 

 

 

 

(cm2/m3)

 

 

 

Hi-Vol EPA                  1970-99

0.26

1,820

260

26

(TSP < 1987; PM10> 1987)

 

 

 

 

WINS EPA                       1999

0.56

3,920

560

56

 

 

 

 

 

Virtual Impactor EPA     1985

0.34

2,380

340

34

 

 

 

 

 

Stacked Filter Unit UCD 1979

0.95

6,650

950

95

 

 

 

 

 

Stacked Filter Unit UCD 1982

0.26

1,820

260

26

 

 

 

 

 

IMPROVE UCD                1988

0.07

490

70

7

 

 

 

 

 

Int. Aerosol Sampler UCD 1999

0.07

490

70

7

 

 

 

 

 

ANALYSIS OF IMPACTORS

 

 

 

 

4 hr sample

 

 

 

 

Sizing, fixed or rotating drum

cm2/m3

pg/m3

pg/m3

pg/m3

 

 

 

 

 

MOUDI  U. Minn.              1985

0.16

1,120

160

16

 

 

 

 

 

DRUM UCD                      1985

1.57

10,990

NA

157

 

 

 

 

 

DELTA-DRUM UCD        1998

0.15

1,050

NA

15

 

 

 

 

 

10 min sample

 

 

 

 

Sizing, single dot or line

cm2/m3

pg/m3

pg/m3

pg/m3

 

 

 

 

 

MOUDI  U. Minn.             1985

NA

NA

NA

NA

 

 

 

 

 

DRUM UCD  (dot)          1985

0.013

1,300

NA

1.3

 

 

 

 

 

DELTA-DRUM (slot)       1998

0.12

10,000

NA

12

 

 

 

 

 

pg/m3 = picograms/cubic meter of air, or 0.001 ng/m3