AN320-en-GB_V1.2 11/14
9
P4.0:
Altitude
Pressure
Compensation
5.
When
in
setup
mode
P4.0,
press
HOLD
to
enter
the
pressure
compensation
parameter.
The
LCD
will
show
hPA
(unit
of
measure:
hector
‐
Pascal
or
millibar)
on
the
lower
line
and
a
flashing
4
‐
digit
number
(from
700
to
1990;
the
default
is
1013
hPA
which
is
standard
pressure)
on
the
upper
line.
6.
Press
U/mode
to
increase
the
pressure
value
and
L/mode
to
decrease
it.
7.
Press
HOLD
once
more
to
return
to
P4.0.
8.
Press
and
hold
the
POWER
SET
button
for
2
seconds
to
return
to
the
normal
operating
mode.
Calibration
CAUTION:
Do
not
calibrate
the
meter
in
air
with
an
unknown
CO
2
concentration.
Doing
so
will
result
in
the
meter
being
calibrated
to
the
standard
400
ppm
and
could
lead
to
inaccurate
results.
1.
Place
the
meter
in
a
calibrated
environment.
2.
With
the
meter
OFF,
press
SET
,
HOLD
and
L/mode
simultaneously
to
enter
CO
2
calibration
mode.
3.
The
meter
will
run
a
30
second
countdown
and
'CAL'
will
show
in
the
lower
display.
4.
During
calibration
a
CO
2
reading
between
380
‐
420ppm
will
flash
in
the
upper
display.
5.
Wait
for
approx.
10
minutes
for
the
reading
to
stop
flashing.
6.
The
calibration
is
now
complete
and
the
meter
will
return
to
the
normal
operating
mode.
7.
To
abort
the
calibration
at
any
time,
turn
OFF
the
meter.
8.
If
the
calibration
fails
for
any
reason
please
return
the
meter
to
Extech
Instruments
for
an
evaluation
and
possible
repair.
