Page:NIOSH Manual of Analytical Methods - 0501.pdf/2

PARTICULATES NOT OTHERWISE REGULATED, TOTAL: METHOD 0501, Issue 1, dated 8 May 2015 - Page 2 of 4

NOTE: The cassettes should be fabricated so as to ensure complete sealing of the internal capsule after sample collection.
 * 1) Sampler: Internal capsule, 37-mm polyvinyl chloride (PVC), 2- to 5-µm pore size membrane or equivalent hydrophobic filter attached to PVC housing and supporting pad in 37-mm 2-piece cassette filter holder
 * 1) Personal sampling pump, 1 to 2 L/min, with flexible connecting tubing
 * 2) Microbalance, capable of weighing to ±0.001 mg
 * 3) Static neutralizer, e.g., 210Po; replace no more than nine months after the production date
 * 4) Tool for handling internal capsules, e.g., forceps (preferably plastic)
 * 5) Environmental chamber or room for balance (e.g., 20 °C ± 1 °C and 50% ± 5% RH)

None.

Equilibrate the PVC filter capsules in an environmentally controlled weighing area or chamber for at least 24 hours.

NOTE: An environmentally controlled chamber is desirable, but not required. Place backup pads in filter cassette bottom sections. Weigh the filter capsules in an environmentally controlled area or chamber. Record the internal capsule tare weight, W$1$ (mg).  Zero the balance before each weighing.  Handle the filter capsule with forceps. Pass the internal capsule over an antistatic radiation source. Repeat this step if the capsule does not release easily from the forceps or if it attracts the balance pan. Static electricity can cause erroneous weight readings.  Assemble the filter capsules in the filter cassettes and close firmly so that leakage around the internal capsule will not occur. Place a plug in each opening of the filter cassette. Place a cellulose shrink band around the filter cassette, allow to dry and label the cassette with indelible ink.</ol>

<li>Calibrate each personal sampling pump with a representative sampler in line.</li>

<li>Sample at 1 to 2 L/min for a total sample volume of 17 to 333 L. Do not exceed a total filter capsule loading of approximately 5 mg total dust. Take two to four replicate samples for each batch of field samples for quality assurance on the sampling procedure.</li></ol>

<li>Wipe dust from the external surface of the filter cassette with a moist paper towelette to minimize contamination. Discard the paper towelette.</li> <li>Remove the top and bottom plugs from the filter cassette. Equilibrate for at least 24 hours in the balance room.</li> <li>Using forceps, open the cassette and remove the internal capsule gently to avoid loss of dust or damage to the capsule.</li></ol> NIOSH Manual of Analytical Methods (NMAM), Fifth Edition