Quick Start Guide

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Measurement Method
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4. Trigger setting
The following describes the trigger condition
setting method.
To activate the trigger at the time of
instantaneous power outage, use "Window In
trigger."
A commercial 100 V power supply has a sine
waveform that ranges from -141 V to 141 V.
In the following setting, the lower limit of the
Window In trigger is set to "-100 V" and the
upper limit to "100 V," and the trigger is
activated when the waveform enters the shaded
range (window) in the left diagram. This setting
activates the trigger every time the waveform
enters the window. Therefore, a time duration
(trigger filter) is set so that the trigger is
activated only when the waveform remains in
the window for longer than the set time.
The frequency of a commercial power supply is
50 Hz, meaning that one cycle is 20 ms.
Instantaneous power outage is a condition in
which the voltage drops for a period longer than
20 ms. Therefore, the trigger filter is used to set
a period in units of DIV. Since the time axis is
set to 20 ms/DIV, the trigger filter is s et to be
longer than 20 ms . In the example, the trigger
filter is set to "1.5 DIV." Wi th th is setting, the
trigger is activated when waveform remains in
the window for 30 ms or longer.
(1) Press the TRIG key to display the trigger screen.
(2) Using the cursor keys, move the flashing cursor to
CH1 "Kind," and press the function key to change
the type to "In."
(3) Move the flashing cursor to CH1 "Parameter," and
set the lower (limit) to "-100.00 V," the upper (limit)
to " 100.00 V," and the filter (Filt.) to "1.5 DIV."
(4) Move the flashing cursor to "Trigger mode," and set
the trigger mode to "Single" (stops after
instantaneous power outage occurs and a
waveform is acquired).
(5) Move the flashing cursor to "Pre-trigger," and set
the pre-trigger to "20%" (for observation of
waveforms prior to the trigger).
< Key point >
By combining the Window In trigger
upper- and lower-limit values with
the filter, it i s possible to detect not
only a trigger caused by an
instantaneous power outage but also
waveform chipping and voltage dips
in repeated waveforms.
Move to "Type," "Parameter,"
"Trigger mode," and "Pre-trigger."
Press the function ke y corresponding to the setting
displayed in the screen.
Trigger screen
Set to "In," "-100.00 V," "100.00 V,"
and "1.5 DIV. "
Display the trigger screen.
Set to "Single" and "20%."