The pDR-1500 needs its filter changed very 24 hours of runtime. Filters may also be used for gravimetric calibration. This activity steps through filter changing.

The Filter

The standard filter for the pDR-1500 is a 37mm fiberglass filter. One such brand is EMD Millipore AQFA03700, these are available from Fisher Scientific in packs of 100. Pre-weighed filters for gravimetric calibration are available from Chester LabNET. Other lab services may be explored from the same labs providing analysis for the Minivol.

• Chester LabNET, 12242 SW Garden Place, Tigard OR 97223. Phone: 503.624.2183

Changing the filter

This procedure is described in section 5-6 of the pDR-1500 Manual.

Materials needed:

• 37mm filter (EMD Millipore AQFA03700)
• PTFE-coated (Teflon®) tweezers (Saint-Gobain D1069288, from Fisher scientific #1031710)
• A clean surface

Unscrew the filter holder:

Remove and open the filter cassette:

Use the tweezers to remove the filter from the filter cassette, handling the filter from the edge and taking care not to bend the filter (especially if it is being sent to a lab):

Place new filter into filter the cassette, handling the filter from the edge and taking care not to bend the filter. There is a notch in the side of the PetriSlide that can be used to approach the edge of the filter:

Place filter cassette back into the pDR-1500. When replaced, the metal screen of the filter cassette should face outwards:

Screw the filter holder cap back on.

Done!

Packing used filter for a lab

If you are sending the filter to a lab, place used filter into the PetriSlide as soon as possible. Record the Filter ID in your monitoring records, check that the correct filter ID is on your PetriSlide holder, and pack for mailing to the lab.