Magni AVM-510A Series, Руководство оператора

Страница: 110 / 182

Automatic Measurement (AVM-510A)
9-4
•
Forcing Live Video

The choice usually used with System Video allows all System Video
parameters to be measured on a live video signal. In the two other measurement sets, forcing Live
Video causes the AVM-510A to measure only those parameters that can be measured on a live
video signal, such as Burst Ampli and Peak Video. The other parameters are grayed out or turned
off.
The measurement set can be applied to a line in the vertical interval or to an active video line. If
you are testing a live video signal that has test signals in the vertical interval, you might want to
select a line with a test signal on it or you might want to measure live video in the active part of
the picture. If you are testing a full-field test signal, you can select any line in the active area.
Automeasurement Set
The quickest way to take automatic measurements is to use the AUTOMEASURE/AUTO MEAS SET
menu option. Selecting this option enables the AVM-510A to automatically determine what test signal
is present on the line you select, and then applies the measurement set that yields the best test results.
To select the AUTOMEASURE/AUTO MEAS SET menu option:
1. Press the Mesmnt button to access the SELECT SET menu.
2. Select SELECT SET and then press the Entr button.
3. Select AUTOMEASURE/AUTO MEAS SET and then press the Entr button.
4. The only selection in this menu is MEASURE LINE. Turn the knob to select the line that has a test
signal. You can turn through the end of one field and into the next field, or you can switch fields
by pressing the
Field Select button.
5. Press the Clr Mnu button to exit.
NOTE:
Usually when you choose something from a menu, it is enough to locate the
item, select it, and then exit the menu. This is not the case with measurement sets.
Whether you are choosing a specific measurement set or AUTOMEASURE/AUTO MEAS
SET, you must first press the
Entr
button to make your choice take effect.
Use caution when operating the AVM-510A in AUTOMEASURE/AUTO MEAS SET mode. The AVM-
510A recognizes a certain list of test signals. If the test signal is not from this list, the AVM-510A
displays the notice Any Signal (Auto) near the top of the automeasurement screen.
In some cases the AVM-510A might recognize a test signal in error. For example, in NTSC, the AVM-
510A cannot determine whether 75% color bars has or does not have setup. In this case, the
measurement set might give false readings.
As a result, always press the
Wfm
button for a quick look at the signal to verify that the AVM-510A
has recognized the correct signal. If measuring a test signal in the vertical iterval, press the Line
Select
button and select the same line (as listed on the measure screen) to see the correct waveform.
Note that the line select number and the line selected in step 4 above are not related.