Leader Electronics Corp. LMV-181A - Advanced Operation and Specifications; LMV-181 B Specific Ranges; Decibel Range Usage; Output Terminal Functionality

LMV-181B
RANGE
Scale
Multiplier
V per DIV
500
V 0
-5
100
10
V
150
V
0-1.5
100
5
V
50
V
0-5
10
1
V
15
V
0-1.5
10
0.5
V
5
V
0-5
1
0.1
V
1.
5V
0-1.5
1
0.05V
500
mV
0
-5
100
10
mV
150
mV
0-1.5
100
5
mV
50
mV
0-5
10
1
mV
15 mV
0
-1.
5
10
0.5
mV
5
mV
0-5
. 1
0. 1
mV
1.
5 mV
0-1.5
1
0.0
5mV
Table
2
7-3
How to
use Decibel Range
The indicator
has the
following
two
red
dB
calibrations:
0
dB
=
0.775 V
(1
mW 600^2
dBm)
0
dB
=
1
V dBV
Table
3
shows
each
dB
range vs dBm
and dBV.
Range
LMV-
-181A LMV-
-181B
setting
dBm
dBV
dBm
dBV
+
50
+
40
+
30
+
20
+
10
0
+
30to+52
+
20to+42
+
10to+32
0to+
22
-lOto+12
—
20to+
2
+
30to+50
+
20to+40
+
10to+30
Oto+20
-lOto+10
—
20to+
0
+
30to+56
+
20to+46
+
10to+36
Oto+26
-lOto+16
-20to+
6
+
30to+54
+
20to+44
+
10to+34
Oto+24
-lOto+14
-20to+
4
-10
-20
-30
-40
-50
-60
-30to- 8
-40to-18
—
50to—
28
—
60to— 38
—
70to— 48
-80to-58
-30
to-
10
-40
to- 20
—
50
to—
30
—
60
to—
40
-70
to- 50
—
80
to— 60
—
30
to—
4
—
40
to—
14
-50
to-
24
-60
to-
34
-70to-44
-80
to-
54
—
30 to—
6
-40to-16
—
50
to—
26
—
60
to—
36
-70
to-
46
-80
to-
56
Table
3
9
Decibel values can be read by
adding
range
dB
values
to
indicated
values
of the pointer.
Example
1
Scale
+
1 dB
Range
+
20
dB
Level
+
21 dBm
Example 2
Scale
-
4
dBV
Range
—
30
dB
Level
-
34
dBV
7-4
Use
of “OUTPUT”
terminal
When the
indicator
show
“1”
[“5”] at
full scale,
the
“OUTPUT”
terminal
can
obtain
an
output of
IVrms no
matter where
the
RANGE
switch is
positioned.
An
oscillo-
scope
can
be
used
as a
monitor
of
measured
signal
wave-
forms, or as a
pre-amplifier by
connection to
the
“OUTPUT”
terminal.
Table 4
shows
the
degrees
of
amplification
when
the
instrument is
used
as a
pre-amplifier.
Notes:
The
following
troubles
will
occur
if a
low
load
impedance
is connected
to
the
terminal.
Resistance
Output
voltage is
lowered.
Low
frequency
characteristics
deteriorate.
Capacitance
As load
capacitance
increases,
high
fre-
quency
characteristics
deteriorate.
Range
setting
(dB;
-60 -50
-40 -30
-20
-10
0
10 20
30
40
50
Degree
of
amplification(dB) 60
50 40 30
20 10
0
-10
-20
-30
-40
-50
Table
4
7-5
Measurement
of
alternating
current
When AC voltage is V,
alternating current
is I
and resistance
is R, there is
a
relationship
as
follows:
1
=
V/R
10