Lambda SR1, Руководство по эксплуатации, Страница: 109 / 317

SR1 Operation 109
© 2014 Stanford Research Systems
When making cross domain measurements that require the input analog sampling rate to be
synchronized to the digital audio output
When making IMD measurements. The Hi-Resolution converter has lower residual IMD distortion.
Level Indicators
For all analyzers except the Jitter analyzer the bottom portion of the analyzer panel displays the levels,
frequencies, and relative phase associated with the selected inputs. For the Time Domain Detector, the
indicated level is a highly accurate RMS measurement of the two input channels. For all other analyzers
the level meter is a less accurate peak-based meter. The phase indicator shows the relative phase
between the A and B channels of the analog or digital audio input signals depending on the selected
input source. The phase indicator reading is only meaningful when A and B channels have the same
frequency.
Analyzer Trigger
Most analyzers can operate in a "triggered" mode. The FFT analyzers, for instance, use the trigger to
synchronize the start of the FFT time record. The Time Domain detector uses the trigger to start the
beginning of each measurement interval. To select "triggered" mode for the analyzer check the
"Enabled" box on the trigger tab. Although each analyzer uses the trigger differently, the method by
which triggers are generated is common to all analyzers.
Trigger Source
Input Channel The trigger source is the selected input signal of the analyzer.
Other Channel The trigger source is the channel not selected as the input of the analyzer. For
instance if the analyzer source is "Analog A" then selecting "other channel" as
the trigger source selects "Analog B"
External Selects a TTL signal on the rear panel "Ext Trigger" BNC connector as the
trigger source.
Manual Only allows manual triggers. Manual triggers are generated by clicking on the
"Manual Trigger" button.
Generator Selects the generator as the trigger source. Use the "Generator Trig Source"