6. Calibrate each personal sampling pump to the appropriate flow rate with a representative sampler
in line.
NOTE 1: Because of their inlet designs, nylon and aluminum cyclones are calibrated within a large
vessel with inlet and outlet ports. The inlet is connected to a calibrator (e.g., a bubble meter).
The cyclone outlet is connected to the outlet port within the vessel, and the vessel outlet is
attached to the pump. See APPENDIX for alternate calibration procedure. (The calibrator can
be connected directly to the HD cyclone.)
NOTE 2: Even if the flow rate shifts by a known amount between calibration and use, the nominal
flow rates are used for concentration calculation because of a self-correction feature of the
cyclones.
7. Sample 45 min to 8 h. Do not exceed 2 mg dust loading on the filter. Take 2 to 4 replicate samples for
each batch of field samples for quality assurance on the sampling procedure (see Step 10).