R&S NRP-Z28/-Z98
Remote Control - Commands
1170.8966.12
6.5
E-4
CALibration:ZERO:AUTO[?] OFF | ON | ONCE
The commands
CALibration:ZERO:AUTO ON
and
CALibration:ZERO:AUTO ONCE
zeroes the three
measurement paths of the sensor. For this purpose, the test signal must be deactivated or the sensor
disconnected from the signal source. The sensor automatically detects the presence of any significant
power to be measured. This causes zeroing to be aborted and error message
NRPERROR_CALZERO
to be output. The
CALibration:ZERO:AUTO OFF
is ignored. Zeroing takes four seconds at a minimum,
but at least as long as the selected averaging filter needs for settling (only fixed-filter mode).
Repeat zeroing
•
during warm-up after switching on or connecting the instrument
•
after a substantial variation of the ambient temperature
•
after fastening the sensor 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.
For zeroing switch off the test signal and do not remove the sensor from the signal source.
Apart from keeping the thermal balance, this has the advantage that the noise
superimposed on the test signal (e.g. from a broadband amplifier) can be detected on
zeroing and does not impair the measurement result.
The query always yields
1
(=
OFF
).
Default setting
After a power-on reset, the zero offsets determined during the last calibration are used until the first
zeroing. Therefore, very slight zero offsets are to be expected with a warmed up sensor. Initialization by
means of
*RST
or
SYSTem:INITialize
has no influence on the current zero offsets.
