SAMPLE PREPARATION:
7. Wipe dust from the external surface of the filter cassette with a moist paper towel to minimize
contamination. Discard the paper towel.
8. Remove the top and bottom plugs from the filter cassette. Equilibrate for at least 2 h in the
balance room.
9. Remove the cassette band, pry open the cassette, and remove the filter gently to avoid loss of
dust.
NOTE: If the filter adheres to underside of cassette top, gently lift using the dull side of scalpel
blade. Take care not to tear the filter.
NIOSH Manual of Analytical Methods (NMAM), Fourth Editio