Leader Electronics Corp. LMV-181A - Operational Guidelines; Input Voltage and Noise Considerations; Measurement Preparation; AC Voltage Measurement Procedure

6-3
Excessive
input
voltage
The
maximum
input
voltage
of
this
instrument
is
AC
peak
+
DC
=
600V.
Do
not
apply
a
voltage
greater
than
this
value,
if
a
larger
input
is
applied
to
the
input
terminals,
circuit
parts
may be
damaged
or
destroyed.
6-4
Input
waveform
This
instrument
gives
indications
according
to
the
mean
value
of
the
input
waveform,
and
the
calibration
is
done
in
effective
values
of
sine
waves.
Therefore,
distortion
of
the
input
voltage
waveform
may
result
in
incorrect
readings.
6-
5
Induction
noise
When
the
measured
voltage
is
very
small,
or
when
the
impedance
of
the
source
of
the
measured
voltage
is
relatively
high,
an
incorrect
indication
may
result
due
to
the
induction
of
external
noises,
if
this
occurs,
use
shielded
cables
to
reduce
or
eliminate
noise
pick-up.
7.
Operation
.
j
.
.
7-
1
Preparation
1.
Before
connecting
this
instrument
to
the
power
source,
check
to
see
that
the
pointer
of
the
scale
is
at
0.
If
it is
off
0,
set
it to 0
by
adjusting
the
zero
adjustment
screw.
2.
Connect
the
power
plug
to
the
power
source
of
the
correct
voltage.
3.
Set
the
range
switch
to
300V
[500V]
in
advance.
4.
When
the
power
switch
is
turned to ON,
the
pilot lamp
should
light.
The
pointer
will
vibrate
irregularly
for about
five
seconds
after
power
goes
on,
but
it
does
not
indicate a
malfunction.
5
The
instrument
will
stabilize
in
about
five seconds
after
power
is
applied.
7
7-2
Measurement
of
AC
Voltage
1.
The
meter
will
indicate
presence
of
voltages
when
a
connection
is
made
to
the
“INPUT”
terminal
and
the
voltage
to
be
measured
is
applied.
2.
if
the
reading
is
less
than
30%
of
full
scale,
turn
the
“RANGE”
button
counterclockwise,
and
reduce
the
volt-
age
range
gradually.
Read
the
indicated
value
when
the
pointer
is
more
than
30%
of
the
full
scale
and
less
than
full
scale.
3.
There
are
two
maximum
voltage
calibrations,
“1”
and
‘
3
[“1.5”
and
“5”],
on
the
scale.
Tables
1
and
2
show
the
positions
of
“RANGE”
buttons
vs.
the
calibration
of
the
voltages
used.
LMV-
181A
Table
1
8