Forwarding WTC air monitoring scope for final review, Aug 2002

NYC 9/11 Public Portal Document

Environmental Protection Agency Pt. 763. Subpt. E, App. A

TABLE 1—NUMBER OF 200 MESH EM GRID OPENINGS (0.0057 mm2) that NEED TO BE ANALYZED TO MAINTAIN SENSITIVITY OF 0.005 STRUCTURES/CC BASED ON VOLUME AND EFFECTIVE FILTER AREA

Effective Filter Area elective Filter Area 385samm ___ eSSsqmm Volume fillers) » ol grid openlnQi 560 24 1,250 24 600 23 1,300 23 700 19 1,400 21 800 17 1,600 19 900 IS 1,800 17 1.000 14 2,000 15 1,100 12 2,200 14 I 1,200 11 2,400 13 I 1,300 10 2,800 12 Recommended 1,400 10 2,800 11 I Volume 1,800 9 3,000 10 I Range 1,600 6 3,200 9 Recommended 1 1,700 8 3,400 9 Volume i 1,800 6 3,600 8 Range 1,900 7 3,800 8 I 2,000 7 4,000 8 I 2,100 6 4,200 7 2,200 6 4,400 7 2,300 6 4,600 7 2,400 6 4,800 6 2,500 5 5,000 6 2,600 5 5,200 6 2,700 5 5,400 6 2,800 5 5.600 5 2,900 5 5,800 5 3,000 5 6,000 5 3,100 4 6,200 5 3,200 4 6,400 5 3,300 4 6,600 5 3,400 4 6,800 4 3,500 4 7,000 4 3,600 4 7,200 4 3,700 4 7,400 4 3.800 4 7.600 4

Note minimum volumes required: 25 mm : 560 Hers 37mm ;l2S0Ulers

FMer dUmeter of 25 mm - sffscHva area of 385 sq mtn FHer diameter o( 37 mm • enective area of 855 sq mm

20. Ensure that the sampler Is turned up­ 22. Ensure that the samples are stored in a right before Interrupting the pump flow. secure and representative location. 21. Check that all samples are clearly la­ 23. Do not change containers If portions of beled and that all pertinent information has these filters are taken for other purposes. been enclosed before transfer of the samples 24. A summary of Sample Data (Juality Ob­ to the laboratory. jectives is shown in the following Table 11:

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