To Monitor for Abnormal Phenomena
8
This procedure is a method for recording occurrences of volt-
age drop-out phenomena such as occur in a power outage.
During continuous monitoring, measurement data is saved
automatically.
This is an example to record power outage by using voltage
drop trigger. This procedure causes a trigger event when volt-
age drops from about 220 Vrms (311.1 Vpeak) to 198 Vrms
(280.1 Vpeak) on a 50 Hz commercial power input signal.
To Monitor for Abnormal
Phenomena
1
Prepare the following before measuring
Trigger Level
T
½
Cycle
Connect to the
measurement points
Items to prepare
Model MR8870-20
AC Adapter (supplied)
Model L9198 Connection
Cord
CF Card
"Measurement Procedure"
(p. 4)
CF card
Connect to CH1
Connect to
power outlet
1
2 3
5
4
Turn the power on
2
Configure measurement settings
1
2
With pre-triggering, you specify that waveform recording is to begin just prior
to the occurrence of an anomaly like a momentary interruption.
Pre-triggering is set by specifying the percentage of the overall waveform re-
cording length to be recorded before the trigger point. (For this example,
record 10 divisions of the waveform before any momentary power drop-outs.)
The trigger point is set to 10 divisions of a total recording length of 20 divi-
sions, so set the pre-trigger to 10/20 [div]
×
100 = 50 [%].
50%
T
20 div
(Recording length)
50%
Select
Apply
Make the following settings on the Measurement Settings screen.
[Timebase]
Set the time per divi-
sion on the horizontal
axis for viewing the
waveform.
[Rng/div]
Set the voltage per di-
vision on the vertical
axis.
[Mag] Vertical Axis Magnification
Set the zoom to
x1/2
when measur-
ing from 200 to 240 V AC commer-
cial power line.
The default settings for the
non-framed items can be
left as-is.
Change as needed.
