Megger SMART THUMP ST16, User Manual

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M
AVTMST16 Rev 1 May 2016
40
Menu item Description
Recall Displays the selected trace on the screen. The screen view can
then be adjusted using any function which does not require the
trace to be updated.
By selecting , the loaded trace is closed and the last
recorded trace is displayed again.
Adjust Trigger
Delay Time
Allows manual adjustment of the trigger delay time (see page 18). It
synchronizes the HV pulse with the LV TDR pulse to a reflection measurement
at the highest or closest to highest current of the arc occurring at the fault
location.
With an adjustment of the trigger delay time, the fault trace, if present, is
erased and a new “live” trace is immediately recorded. Typical value for the
ST16 is 700
μ
s.
Adjust Pulse
Width
Allows manual adjustment of the pulse width.
Pulse width is automatically selected as a function of cable length Narrow
pulses lead to short ranges but at very high resolution. Wide pulses which
provide lower resolution have to be used when measuring on long cables.
With an adjustment of the pulse width, the fault trace, if present, is erased and
a new “live” trace is immediately recorded.
Change
transformer
sensitivity
Only applicable in combination with the sectionalizing software. Allows manual
adjustment of the transformer search sensitivity. Decreasing or increasing the
sensitivity has an effect on the number of transformers identified by the
software,
but will not change the position of the transformers relative to
each other and the 2 cable ends.
Note: The sectionalizing method is typically only used in
North American URD loop type circuits!
Find Transformers
in Actually Trace
Allows manual start of the transformer search.
Disable live
trace/
Enable live
trace
Disables / enables continuous “live” trace recording.
For most operators it is beneficial to “disable live trace”, which means the
trace is always live and any adjustment becomes immediately visible.