UFC 3-570-06
JANUARY 31 2003
systems. If a protected structure is designed to protect an isolated structure, shorts to
other structures will normally result in loss of adequate protection to that structure.
Shorts may also result in the current distribution being adversely affected, and
consequent loss of protection to areas of the structure. Determination of shorted or
isolated conditions is also important in the design phase of cathodic protection
installations. The preferred method for testing for a short between two structures is
potential testing. This method will normally provide immediate indication if the two
structures are not shorted, and at the same time provide valuable potential data. The
methods of potential measurement will vary slightly if cathodic protection is supplied to
neither structure, one structure, or both structures. A power supply may be required if
one or both structures do not have CP installed. If only one structure has CP, refer to
the procedures in paragraph 7-9.1. If both structures have CP, refer to the procedures
in paragraph 7-9.2. If neither structure has CP, refer to the procedures in paragraph 7-
9.3.
underground structures. If the structures are isolated, current will flow through the
meter and damage could result. If that current does not damage the meter, the
measurement would not indicate a resistance value. The voltage would be interpreted
by the meter as coming from the internal battery instead of the external electrical circuit
being measured.
7-9.1
Testing for a Short Between Two Structures with Cathodic Protection
on One Structure. Take a potential measurement of both structures by changing only
the structure connection without moving the copper/copper sulfate reference electrode.
7-31
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