The Spectrum Application (RF Measurements)
R&S
®
FPL1000
261
User Manual 1178.3370.02 ─ 11
Final Measurement at the Marker Position
Finding peaks with the help of an initial marker peak search reduces data to be evalu-
ated and thus measurement time. A final measurement with a special EMI detector can
then refine the initial results.
The R&S
FPL1 EMI measurement performs the final measurement automatically as
soon as a detector for the final test is defined for an EMI marker and the marker is acti-
vated. The final measurement starts immediately after the marker has been set. The
advantage of an immediate final measurement is that it eliminates the risk of measure-
ment errors based on frequency drifts of the disturbance signal.
The final measurement at the marker frequency can have a different detector than dur-
ing the initial peak search. Thus, the final measurement consumes much less time
because detectors with a long measurement time are needed only at the critical fre-
quency.
The R&S
FPL1 EMI measurement also allows you to use multiple detectors for the
final measurement. The advantage of multiple detections is that you only need one test
run to see if the results comply with the limits specified in a standard. The detectors for
the final EMI tests are defined in the marker configuration, as opposed to the
trace
detector which is used for the initial peak search.
The results of the final measurement are shown in the Result Summary (see
ter 6.2.14.2, "EMI Measurement Results"
Defining a dwell time for the final measurement
EMC tests often require a specific
dwell time
for an EMI measurement. The dwell time
defines how long the R&S
FPL1000 measures the signal at the frequencies of the
marker positions. The dwell time is identical for all EMI final measurements and is thus
defined in the EMI measurement configuration. Select a dwell time according to the
characteristics of the measured signal. See also
Limit Checks
General limit line functionality is provided by the R&S
FPL1000 base unit. The base
unit also provides various predefined limit lines that you can use for various applica-
tions. The EMI measurement adds further predefined limit lines designed in compli-
ance with several EMC standards.
When using limit lines in combination with EMI measurements, the marker levels from
the initial measurement are compared to the limit line values. The result of the limit line
check is displayed in the diagram as usual.
In the EMI Result Summary, the limit check is based on the results of the final test.
Since the marker can be determined using a different detector than the final test
results, the two limit check results can differ. The difference between the limit line and
the measured value is colored to indicate the following states:
●
green
: does not exceed limit
●
yellow
: within margin
●
red
: exceeds limit
Measurements and Results
