Alco
‐
Sensor
FST®
Operator’s Manual
PROTECTED
A
Alco
‐
Sensor
FST®
Operator’s
Manual
13
of
30
2018
‐
12
‐
18
The
Alco
‐
Sensor
FST®
has
an
automatic
sampling
system
designed
to
ensure
that
a
sample
of
deep
lung
air
is
obtained
and
analyzed.
In
order
to
trigger
automatic
sampling
the
subject
must
blow
with
a
minimum
flow
rate,
must
produce
a
minimum
breath
volume
and
blow
for
a
minimum
duration.
When
the
minimum
flow
rate
is
met
a
continuous
tone
will
sound,
the
head
icon
will
stop
flashing,
the
message
Blow
will
disappear,
and
one
of
three
progressive
dashes
will
appear
to
the
right
of
the
icon.
If
the
subject
continues
to
blow
while
exceeding
the
minimum
flow
rate
two
more
dashes
will
appear
to
the
right
of
the
head
icon.
If
the
subject
stops
blowing
before
the
sampling
requirements
have
been
met,
one
of
the
four
flow
messages
will
appear
and
the
device
will
re
‐
cycle
to
allow
a
second
attempt
to
provide
a
sample.
After
a
very
short
wait
the
flashing
head
icon
will
reappear
and
the
subject
should
be
directed
to
blow
again.
The
device
will
allow
up
to
three
attempts
to
provide
a
breath
sample
for
each
test
sequence.
When
all
the
sampling
requirements
are
met
there
will
be
an
audible
click
and
the
sample
will
be
accepted
and
analyzed.
The
analysis
of
the
breath
sample
usually
takes
less
than
10
seconds
to
complete
and
there
are
three
possible
results:
The
test
result
will
be
displayed
for
about
ten
seconds
and
then
the
device
will
power
off
automatically.
Show
the
reading
to
the
subject.
You
can
recall
the
test
result
using
the
menu
function,
LAST
(see
Alco
‐
Sensor
FST®
Menu
Functions
on
page
17).
4.2
Theory
and
Design
of
the
Alco
‐
Sensor
FST®
The
Alco
‐
Sensor
FST®
contains
a
fuel
cell
sensor
and
an
electrically
operated
sampling
system.
A
pressure
sensor
in
the
device
monitors
breath
flow
and
volume
to
determine
when
to
capture
a
breath
for
analysis.
While
a
subject
is
blowing
and
when
deep
lung
breath
is
reached
the
sampling
system
is
activated.
A
small,
fixed
volume
of
deep
lung
breath
is
drawn
onto
the
surface
of
the
fuel
cell,
any
alcohol
present
in
the
sample
is
oxidized,
generating
a
current.
The
resulting
electric
current
is
translated
into
a
blood
alcohol
concentration
and
the
result
is
displayed
on
the
Alco
‐
Sensor
FST®
in
blood
alcohol
concentration
units
of
milligrams
of
alcohol
in
100
milliliters
of
blood
(mg%).
Display
‐
The
display
and
the
back
light
turn
on
when
the
device
is
powered
ON.
Various
commands
and
symbols
appear
on
the
display
to
direct
the
operator
through
the
testing
procedure
and
alert
the
operator
of
improper
testing
conditions
detected
by
the
system.
Result
displayed
on
screen
BAC
Level
Digital
Numerical
Reading
0
to
59
mg%*
WARN
60
to
99
mg%
FAiL
100
mg%
or
higher
