Model 2750 Multimeter/Switch System User’s Manual
Rel, Math, Ratio, Channel Average, dB
5-21
dB
Expressing DC or AC voltage in dB makes it possible to compress a large range of mea-
surements into a much smaller scope. The relationship between dB and voltage is defined
by the following equation:
where: V
IN
is the DC or AC input signal.
V
REF
is the specified voltage reference level.
The instrument will read 0dB when the reference voltage level is applied to the input.
If a relative value is in effect when dB is selected, the value is converted to dB then REL is
applied to dB. If REL is applied after dB has been selected, dB has REL applied to it.
NOTE
The dB calculation takes the absolute value of the ratio V
IN
/ V
REF
.
The largest negative value of dB is -160dB. This will accommodate a ratio of
V
IN
= 1µV and V
REF
= 1000V.
dB configuration
Remote programming must be used to configure the Model 2750 for dB measurements. It
cannot be configured from the front panel.
Scanning
Typically a scan using dB is configured and run using remote programming. However,
once dB is selected using remote programming, a simple dB scan can be configured and
run from the front panel. When the simple scan is configured, it will use the dB measure-
ment setup for each channel in the scan. Details on configuring and running a scan are pro-
vided in
NOTE
See
to configure and run a scan.
Remote programming — dB
dB commands
The dB commands are listed in
. Details on these commands follow the table.
NOTE
Queries are not included in
. All the dB commands are provided in
dB
20log
V
IN
V
REF
-------------
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2750-900-01.book Page 21 Wednesday, August 3, 2011 7:56 AM
Summary of Contents for 2750
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Page 324: ...12 CommonCommands 2750 900 01 book Page 1 Wednesday August 3 2011 7 56 AM...
Page 348: ...15 SCPIReferenceTables 2750 900 01 book Page 1 Wednesday August 3 2011 7 56 AM...
Page 374: ...B Model7700ConnectionGuide 2750 900 01 book Page 1 Wednesday August 3 2011 7 56 AM...
Page 386: ...C StatusandErrorMessages 2750 900 01 book Page 1 Wednesday August 3 2011 7 56 AM...
Page 394: ...D SignalProcessing SequenceandDataFlow 2750 900 01 book Page 1 Wednesday August 3 2011 7 56 AM...
Page 408: ...E MeasurementConsiderations 2750 900 01 book Page 1 Wednesday August 3 2011 7 56 AM...
Page 428: ...G IEEE 488BusOverview 2750 900 01 book Page 1 Wednesday August 3 2011 7 56 AM...