- 4 -
Turn
‐
On,
Sensitivity
and
Volume
Settings
Turn
on
the
GA
‐
72Cd
by
rotating
the
On/Off
‐
Sensitivity
control
knob
clockwise
to
position
1.
This
sets
the
sensitivity
to
what
is
referred
to
as
the
Normal
Range
(the
L
meter
indication).
Sensitivity
can
be
increased
by
rotating
the
Sensitivity
control
clockwise
to
select
M,
H,
or
XH
settings
(as
indicated
on
the
meter’s
GAIN
display).
Adjust
the
Volume
control
for
the
desired
audio
output
level.
ON/OFF
Headset
Jack
Sensitivity
(also
output
for
Levels
Data
Logger)
Volume
Control
Magnetic
Field
Signal
Strength
Polarity
(in
differential
milligauss)
Selected
Sensitivity
Battery
Charge
Level
Indicator
Indicator
Negative
Polarity
Positive
Polarity
Expanding
Bar
Graph
Expanding
Bar
Graph
Figure
2:
Control
and
Meter
Indications
Battery
Level
Indication
The
meter’s
BATT
indication
displays
the
batteries’
voltage
level.
When
all
four
segments
are
black,
the
voltage
level
is
between
100%
and
25%
(up
to
40
hours
of
operation
with
intermittent
usage).
As
the
voltage
decreases,
the
number
of
black
segments
decreases.
Battery
life
varies
with
usage
and
the
ambient
temperature.
Cold
temperatures
reduce
battery
life.
Low
temperatures
may
result
in
only
two
or
three
segments
being
black;
this
could
be
temporary
and
all
segments
will
change
back
to
black
as
the
temperature
increases.
100 to 25%
25 to 20%
20 to 10%
10 to 1%
Figure
3:
Battery
Voltage
Status
Indications
