TE-WILBUR OPERATIONS MANUAL REV 002.22 4/27/2017
Tisch Environmental 1-TSP-AND-PM10 email@example.com www.tisch-env.com Page 34 of 185
4.6 Filter and Filter Cassette
The filter specifications for PM2.5 and PM10 sampling are detailed in EPA QA
Guidance Document 2.12 – Monitoring PM2.5 in Ambient Air Using Designated
Reference for Class I Equivalent Methods and are as follows:
o Material – PTFE Teflon with integral support ring.
o Size- circular 46.2mm diameter +/- 0.25mm (with support ring).
o Support ring – Polymethylpentene (PMP) or equivalent inert material,
0.38 ± 0.04mm thickness, outer diameter 46.2 ± 0.25mm, and width of
o Pore size – 2µm as measured by ASTM F 316-94.
o Thickness – 30-50µm.
o Maximum pressure drop of a clean filter is 30cm of water column at
16.67 L/min clean air flow.
o Maximum moisture pickup – no more than 10µg weight increase after
24 hour exposure to air at 40% RH, relative to the weight after a 24 hour
exposure to air at 35% RH.
o Collection efficiency – greater than 99.7% as measured by the dioctyl
phthalate (DOP) test (ASTM 1995c) with 0.3µ m particles at the
sampler’s operating face velocity.
o Filter weight stability (including test for loose, surface-particle
contamination and test for temperature stability) - filter weight loss ≤
20µg in either test, measured as specified in 40CFR Part 50, App. L,
o Alkalinity – less than 25 micro-equivalents/g of filter, as measured in a
procedure based on Appendix A of EPA QA Guidance Document 2.12
– Monitoring PM2.5 in Ambient Air Using Designated Reference ro
Class I Equivalent Methods.