How to Use the Instrument
Description and Applications of the Test Patterns
4
4-75
Figure 4-114. Video Menu with Reference Line Popup
Switching off IRS:
•
Call up the
Reference Line
popup menu, as described above.
•
Select
Off
by the
é
or
ê
softkey (F1, F2)
•
Press the
enter
softkey (F5).
The IRS signal in TV lines 17 and 330 is switched off. The
video
menu shows
Reference Line Off
.
Applications:
This signal combination is mainly used as a test line for automatic measurement and
monitoring of TV signals. The luminance bar also serves as amplitude reference for
automatic level control.
The following distortions can be measured using the IRS signal:
•
Luminance bar:
distortion, level error, line time waveform, overshoot and rounding.
•
2T pulse:
group delay, amplitude error, pulse distortion, and reflections.
•
20T pulse:
amplitude and delay difference between luminance and chrominance.
For details, see Figures below.
•
Staircase luminance signal:
static nonlinearity, amplitude nonlinearity.
Figure 4-116.
IRS 20T Pulse, Delay Error
Figure 4-115.
IRS 20T Pulse, Chroma Amplitude Error
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