Making Distance-Domain Measurements
Distance domain measurements—commonly known as distance-to-
fault (DTF)—are made over a selectable distance range. They return in-
formation that can help locate discontinuities in a transmission line.
Selecting a Frequency Range
NOTE:
The maximum distance range is determined by the
frequency span, number of data points, and relative
propagation velocity:
Maximum Unaliased Range
V
F
F
f
=
´
-
( .
) (
) ( )
15
10
129
2
1
8
Where: F1 is start frequency
F2 is stop frequency
Vf is relative propagation velocity
maximum unaliased range is in meters.
Refer to Figure 2-10, page 2-36, for a plot of maximum
distance range versus frequency span.
Step 1.
Press the FREQ soft key, from the Main Menu (page
2-8).
Step 2.
Press the F1 soft key from the ensuing soft key menu.
Step 3.
Enter the desired numerical value using the keypad or
the Up/Down Arrow key (Figure 2-1, page 2-0).
Press
ENTER
when data entry is complete.
Step 4.
Press the F2 soft key.
2 - 35
Chapter 2 Operation