Labconco Biological Safety Cabinets 30268 Series User Manual
Page 21
Product Service 1-800-522-7658
15
Original instructions
C
C
h
h
a
a
p
p
t
t
e
e
r
r
4
4
:
:
P
P
e
e
r
r
f
f
o
o
r
r
m
m
a
a
n
n
c
c
e
e
F
F
e
e
a
a
t
t
u
u
r
r
e
e
s
s
a
a
n
n
d
d
S
S
a
a
f
f
e
e
t
t
y
y
P
P
r
r
e
e
c
c
a
a
u
u
t
t
i
i
o
o
n
n
s
s
All Purifier Logic+ Biosafety Cabinets operate using the following
principles:
• Filtration and retention of particulates by High Efficiency Particulate
Air (HEPA) filter(s)
• Laminar airflow
• Directional airflow
The major components in a biosafety cabinet are:
• The HEPA filter(s) or optional ULPA filters
• The motor/blower to force air through the cabinet
• Cabinet air intakes (grilles), ductwork and air balance controls
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 typically held in place 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 4-1.
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. Thus, the filters used in the Logic+ cabinets are at least 99.99%
efficient in removing particles 0.3 micron.