R&S FSH
Measurements on CW Signals
1145.5973.12 2.5
E-11
Power Measurements Using the Power Sensor
For highly accurate power measurements, the R&S FSH provides the Power Sensor R&S FSH-Z1 or
R&S FSH-Z18 as options. They measure power in the span 10 MHz to 8 GHz or 10 MHz to 18 GHz,
respectively.
The Power Sensor R&S FSH-Z1 or R&S FSH-Z18 is controlled and powered via a special RS-232-C
interface at the top of the instrument.
RF connector
(Device under Test)
Power Sensor
R&S FSH-Z1 or
R&S FSH-Z18
Power Sensor
connector
The continuous power applied to the power sensor’s input must not exceed 400 mW
(26 dBm). However, brief (
≤
10 µs) power peaks up to 1 W (30 dBm) are permissible.
Higher input powers can destroy the sensor. An attenuator pad must be used to ensure
that the maximum permissible power for the sensor is never exceeded when
measurements are made on high-power transmitters.
!
Connect the power sensor cable to the R&S FSH’s power sensor connector and screw it into
position.
!
Press the MEAS key.
!
Press the MEASURE softkey.
!
Using the cursor keys or the rotary knob, select the POWER SENSOR menu item and confirm your
selection with the ENTER key or the MEASURE softkey.
The R&S FSH opens the screen for power measurements. If a power sensor has not been connected,
no measured value is displayed. If a power sensor has been connected, the R&S FSH sets up a
connection via the RS-232-C interface and, after a few seconds, displays the measured power.
If there are any communication problems with the power sensor, the R&S FSH outputs error messages
(sensor error: error number) indicating the possible causes (see main manual).
To compensate for internal offset of the power meter, it needs to be compensated before starting the
measurement.
