shall be measured. The locations of these measurements shall be identical
to the locations specified for [pipe-] [tank-] [_____] to-reference
electrode potential measurements.
3.5.2
Isolation Testing
Before the anode system is connected to the [pipe] [tank] [_____], an
isolation test shall be made at each isolating joint or fitting. This test
shall demonstrate that no metallic contact, or short circuit exists between
the two isolated sections of the [pipe] [tank]. Any isolating fittings
installed and found to be defective shall be reported to the Contracting
Officer.
3.5.2.1
Insulation Checker
A Model 601 insulation checker, as manufactured by ["Gas Electronics"]
[_____] [or] [an approved equal], shall be used for isolating joint
(flange) electrical testing ing accordance with anufacturer's operating
instructions. An isolating joint that is good will read full scale on the
meter; if an isolating joint is shorted, the meter pointer will be
deflected at near zero on the meter scale. Location of the fault shall be
determined from the instructions and the joint shall be repaired. If an
isolating joint is located inside a vault, the pipe shall be sleeved with
insulator when entering and leaving the vault.
3.5.2.2
Cathodic Protection Meter
A Model B3A2 cathodic protection meter, as manufactured by ["M. C. Miller"]
[_____] [or] [an approved equal] using the continuity check circuit shall
be used for isolating joint (flange) electrical testing. This test shall
be performed in addition to the Model 601 insulation checker. Continuity
is checked across the isolated joint after the test lead wire is shorted
together and the meter adjusted to scale. A full scale deflection
indicates the system is shorted at some location. The Model 601 verifies
that the particular insulation under test is good and the Model B3A2
verifies that the system is isolated. If the system is shorted, further
testing shall be performed to isolate the location of the short.
3.5.3
Anode Output
After the rectifier is energized, the current output of the individual
anode leads shall be measured by using an approved method. This may be
done with a shunt and MV meter, a low-resistance ammeter, or a clamp-on
milliammeter. The total current shall be measured and compared to the sum
of all anode currents and to the rectifier output current. If an
individual anode output current meets or exceeds the recommended output for
that anode, the system shall be turned down or balancing resistors
installed. Calculation of the wattage of the resistors shall be sufficient
to handle the maximum load which will be encountered on the anode lead.
All measurements obtained, the date, time, and locations of all
measurements shall be recorded.
3.5.4
Electrode Potential Measurements
Upon completion of the installation and with the entire cathodic protection
system in operation, electrode potential measurements shall be made using a
copper-copper sulphate reference electrode and a potentiometer-voltmeter,
or a direct current voltmeter having an internal resistance (sensitivity)
of not less than 10 megohms per volt and a full scale of 10 volts. The
SECTION 13112A
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