Rohde & Schwarz SMC100A, Руководство по эксплуатации

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Instrument Function
R&S
®
SMC100A
116 Operating Manual 1411.4060.32 ─ 04
In which unit the measured value is indicated is selected here and might be Watt, dBm
or dBuV.
SCPI command:
​
SENSe<ch>:
​
UNIT[:
​
POWer]
​
on page 242
Permanent Display State - Power Sensors
Activates the permanent indication of the power measurement result in the upper right
corner of the block diagram. The instrument shows the type of sensor, the corresponding
connector, the measurement source and - if set - the offset.
It is possible to switch the permanent display active for several sensors. In this case, the
instrument indicates the values of the sensor with the lowest port number in the display.
SCPI command:
​
SENSe<ch>[:
​
POWer]:
​
DISPlay:
​
PERManent:
​
STATe
​
on page 236
Display Priority - Power Sensors
Selects whether the average or the peak power measurement result is indicated when
permanent display is active.
SCPI command:
​
SENSe<ch>[:
​
POWer]:
​
DISPlay:
​
PERManent:
​
PRIority
​
on page 236
Zero - Power Sensors
Activates the auto zero function.
Zeroing calibrates the external power sensor by adjusting its reading at zero signal power.
For this purpose, the RF power source must be switched off or disconnected from the
sensor (see tips below). R&S power sensors automatically detect the presence of any
significant input power. This aborts zeroing and generates an error message. Zeroing
can take a few seconds, depending on the sensor model; refer to the documentation of
your external power sensor for more information.
Tips for zeroing
Zeroing should be performed:
●
During warm-up after switching on or connecting the instrument
●
After a substantial change of the ambient temperature
●
After fastening the power sensor module to an RF connector at high temperature
●
After several hours of operation
●
When very low-power signals are to be measured, e.g. less than 10 dB above the
lower measurement limit.
●
Switch off the RF power source for zeroing; do not disconnect it from the power sen-
sor. In this way you will maintain the thermal equilibrium, and zeroing will also com-
pensate for the noise superimposed on the measured signal (e.g. from a broadband
amplifier).
SCPI command:
​
SENSe<ch>[:
​
POWer]:
​
ZERO
​
on page 241
Source - Power Sensors
Selects the source for measurement.
RF Signal - RF Block