VON MODEL SST15-832 ARC REFLECTION SECTIONALIZING SYSTEM Page 20
fault can be determined.
Where D
1
= Actual distance to the fault
D
2
= Actual distance to known point
t
1
= Distance provided by radar to fault
t
2
= Distance provided by radar to known point
The three stake method or two terminal method of locating faults is used when the velocity of
propagation or a specific distance is not known. This method can also be used whenever
maximum accuracy is required.
a.
Take a reading from one end of the cable to the fault. Measure out the distance with a
wheel and drive a stake.
b.
Without changing the propagation velocity on the radar take a reading from the
opposite end of the cable. Again measure out the distance with a wheel and drive a
stake.
c.
The fault will lie between the two stakes. By using the following formulas, the fault
location can be determined.
Where D
1
= Distance to the fault
t
1
= Radar distance reading from point 1
t
2
= Radar distance reading from point 2
e
1
= Error distance between t
1
and the actual distance to the fault D
1
e
2
= Error distance between t
2
and the actual distance to the fault
(e
1
+ e
2
) = Distance between stakes
F:\DOCUMENT\MANUAL\SST\SST-832.01.wpd
Summary of Contents for SST15-832
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