Filter
Top Products
2-30
Making Measurements
Measuring Signal-to-Noise Ratios with Averaging
averages taken so far. The maximum number of averages is 900, the
minimum number of averages is 10, and the default (Preset) value is
100 averages. A measurement with 100 averages takes about 2 minutes
to complete. When the measurement is complete, the instrument
switches to single measurement mode. Then, pressing the Cont key will
start a completely new measurement. During a measurement and
before the number of averages has been reached, pressing the Single
key will stop the measurement. Then, pressing the Cont key will con-
tinue with the current measurement.
While making a signal-to-noise with averaging measurement, the num-
ber of averages can be changed. As long as the new number of aver-
ages is greater than the number of averages taken so far, the
measurement continues. If the new number of averages selected is less
than the number of averages taken so far, the measurement stops and
the instrument switches to single measurement mode. Then, pressing
the Cont key will start a completely new measurement.
Noise bandwidth
affects
measurement
When measuring noise power, the Agilent 86120C must account for the
noise bandwidth used during the measurement. Because noise band-
width varies with measurement bandwidth (a wide bandwidth allows
more noise to the Agilent 86120C’s detector than a narrow bandwidth),
the Agilent 86120C normalizes all noise power measurements to a
bandwidth of 0.1 nm. The annotation 0.10 nm is displayed to show
that the noise bandwidth is being normalized to a 0.1 nm bandwidth.
To measure signal- to- noise with averaging
1 Press the front panel Preset key.
2 Press List by WL or List by Power.
3 Press Appl's and then S/N AVG.
4 To change the number of averages, press NUM AVG. The default (Preset)
value is 100.
5 To stop the measurement at the current number of averages shown,
press the Single key. Then press the Cont key to continue the present
measurement.
6 When the measurement is complete, the instrument will switch to the
single measurement mode and stop.
7 To make a new measurement, press the Cont key.
8 To exit, press the EXIT softkey, then press the Cont key for continuous
measurement.