Chapter 4: Performance Features and Safety Precautions
Product Service 1-800-522-7658
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Optional Evidence Prefilters
Optional Evidence Prefilters can be fitted on the inside (cabinet side) of the door
prefilter (located on the front of the door) and cabinet prefilter (located on the
inside top of the liner). These thin prefilters are designed for single-use, to be
removed after the evidence has dried. After removal, the Evidence Prefilters can be
examined for trace evidence, or stored with the evidence in a sealed bag for future
reference. See Appendix A for reorder part numbers.
Prefilters
Both the door prefilter (located on the front of the door) and cabinet prefilter
(located on the inside top of the liner) are disposable, polyester particulate filters.
Both filters have a Minimum Efficiency Reporting Value (MERV) of 11, meaning
they remove 65-79% of particles 1.0-3.0 microns in size, and more than 85% of
particles 3.0-10 microns in size. See Appendix A for reorder part numbers.
HEPA Filters
HEPA filters are disposable, dry-type particulate filters. The filter material or
media is typically made of borosilicate microfibers formed into a thin sheet, in a
process similar to the production of paper. This sheet is folded, or pleated to
increase its surface area. The pleats are held in place by aluminum diffusers or by
beads of glue that add rigidity to the media pack. The pack is then set into a frame,
and sealed as shown in Figure 4-2.
The HEPA filter manufacturer establishes the efficiency of the filter by challenging
it with an aerosol of known particle size. The number of particles that penetrate the
filter are quantified, and this establishes the efficiency of the filter. The filters used
in the evidence drying cabinets are at least 99.99% efficient in removing particles
0.3 micron.
Note:
The HEPA filter media is very fragile. DO NOT touch the media. If
you think the media of a HEPA filter is damaged, DO NOT USE THE
CABINET.
Call Labconco’s Product Service Department at 1-800-522-7658 or
816-333-8811.
Note:
HEPA Filters are only effective against particulate material. Gases will pass
through the filter.
Figure 4-2
Polyurethane seal
Between media pack
and filter frame
Filter frame
Filter media pack –
A continuous sheet
of filter media
