AN320-en-GB_V1.2 11/14
6
Operation
Air
Velocity
and
Air
Volume
Measurements
1.
Switch
the
meter
ON
by
pressing
the
POWER
button
momentarily.
The
meter
will
countdown
from
30
to
0
as
it
performs
a
self
‐
test.
Press
the
POWER
button
again
to
switch
the
meter
OFF.
2.
Note
that
the
meter
will
automatically
enter
the
sleep
mode
after
20
minutes
of
inactivity.
To
disable
this
feature:
with
the
meter
OFF,
press
and
hold
the
POWER
and
the
U/mode
buttons
for
2
seconds.
The
LCD
will
display
'
n
'
as
it
switches
ON.
Now
the
sleep
mode
is
disabled
and
the
user
must
press
the
POWER
button
momentarily
to
switch
the
meter
OFF.
3.
When
the
meter
is
ON,
the
upper
display
can
indicate
air
velocity,
relative
humidity,
or
CO
2
(use
the
U/mode
button
to
scroll).
The
lower
display
digits
can
indicate
air
flow,
dew
point
temperature,
wet
bulb
temperature,
or
air
temperature
(use
the
L/mode
button
to
scroll).
4.
Place
the
sensor
in
the
air
stream.
The
air
must
enter
the
vane
from
the
rear
of
the
meter.
The
Air
Temperature,
Relative
humidity,
and
CO
2
sensors
are
located
at
the
center
of
the
vane
on
the
rear
of
the
meter.
5.
Read
the
measurement
data
on
the
LCD.
Air
velocity
readings
are
indicated
in
meters
per
second
(m/s)
or
feet
per
minute
(fpm).
Temperature
readings
(air,
dew
point
DP,
or
wet
bulb
WBT)
are
indicated
in
°C/°F.
Air
flow
(volume)
is
indicated
in
CFM
(cubic
feet
per
minute)
or
CMM
(cubic
meters
per
minute).
Use
the
L/mode
button
(for
lower
display)
and
the
U/mode
button
(for
upper
display)
to
scroll
through
the
displayed
reading
options.
6.
To
change
between
Imperial
and
Metric
units
of
measure
refer
to
the
SETUP
Mode
section.
7.
To
measure
the
Air
Volume
of
a
duct,
first
measure
the
duct’s
area
(see
the
Appendix
for
area
calculations)
and
then
enter
the
area
value
in
the
meter’s
SETUP
mode
in
in
2
or
cm
2
.
After
the
area
value
has
been
entered,
use
the
L/mode
button
to
scroll
to
the
air
volume
display
(CMM/CFM)
on
the
lower
digits.
Place
the
meter
in
air
stream
to
measure
volume.
8.
Optional:
measure
Air
Volume
with
an
airflow
Cone
or
Square
adaptor
by
first
attaching
one
of
the
adaptors
to
the
meter
(the
optional
cone
adaptor
kit
includes
a
round
and
a
square
cone;
kit
part
number
AN300
‐
C).
The
meter
will
automatically
recognize
that
the
adaptor
is
attached
to
the
meter
and
a
cone
icon
will
appear
on
the
display.
Note:
regardless
of
the
AREA
setting
in
the
SETUP
mode,
the
meter
will
default
to
the
dimensions
of
the
vane
opening.
Ensure
that
the
airflow
adaptor
is
well
mounted
and
locked
before
taking
measurements.
LCD
backlight
Press
the
U/mode
button
to
switch
ON
the
LCD
backlight.
The
backlight
will
automatically
switch
OFF
after
approximately
10
seconds
to
conserve
battery
power.
Note
that
the
backlighting
switches
ON
automatically
when
the
meter
is
switched
ON
by
the
user.
