Philips PM2521 Operating Manual page 50

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Selection of the trigger level
— Select the + or — trigger level by depressing pushbutton +/—.
Remark:
Signals which are higher or lower than the circuit zero of the PM 2521 (0 terminal) can be triggered with the
+ or — trigger level respectively.
In + trigger level mode the PM 2521 triggers on positive crossings of the trigger level. In — trigger level mode the
PM 2521 triggers on negative crossings of the trigger level.
TRIGGER POINTS (++) TRIGGER POINTS (--)
-T-TRIGGER
-*• LEVEL
ST 3015
820226
Fig. 20. Trigger level selection in peak voltage measurement mode.
— Adjust the trigger level with the thumbwheel-until the GATE indication on the display is ignited.
Remark:
The trigger level can be adjusted between zero and end of range.
The voltage reading on the display indicates the height of the trigger level.
If the input signal cannot be triggered, proceed as follows:
— Select another trigger level polarity depressing pushbutton +/— and try to trigger again.
— Check whether the input signal is lower than 7.5 % of the end of range value of the selected trigger level
range. Signals lower than 7.5 % cannot be triggered accurately.
— Select a higher trigger level range by depressing pushbutton UP and try to trigger again.
Measurement of the peak voltage
— Adjust the trigger level with the thumbwheel until the GATE indication on the display just switches on or
off. The voltage of the trigger level equals the peak voltage of the input signal.
Examples:
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