Agilent Technologies ENA Series

96 Chapter 7
Characteristics
Fault Location Distance Range and Resolution
Fault Location Distance Range and Resolution
Resolution improves as the range is shortened and as the number of measurement
points are increased. (See the following tables and graphs.) Distance is displayed in
feet or meters. Typical range is limited by transmission line losses.
NOTE The following distance range discussion assumes that one way reflection
measurement is selected.
Range
Maximum range is a function of the velocity factor (V
f
), frequency span (F
s
), the
velocity of light in a vacuum (c = 2.99796 X 10
8
m/sec), and the number of
measurement points (NP), and is determined (in meters) using the following
formula:
Resolution
Maximum resolution is a function of the velocity factor (V
f
), frequency span (F
s
),
sampling factor (N
s
: 128 for 101 points, 256 for 201 points, and 512 for 401 points),
the velocity of light in a vacuum
(c = 2.99796 X 10
8
m/sec), and the number of measurement points (NP), and is
determined (in meters) using the following formula:
Range
V
f
c()NP 1–()
2 F
s
()
-----------------------------------
StopDis cetan==
Resolution
V
f
c()NP 1–()
2 F
s
()N
s
()
-----------------------------------
Range
N
s
----------------
StopDis cetan
N
s
-----------------------------------
===