Installing C.P. Components 8:12
CP 1 – Cathodic Protection Tester Course Manual
© NACE International, 2000
07/01/04
Electric resistance probes are also used in oil heater-treater and other
vessels, water storage tanks, and on marine structures. Rate of corrosion is
measured with the same instrument as discussed above.
Wire Attachment
General
The structure, test lead wires, or bond cables should be clean, dry, and free
of foreign materials at points of connection when the connections are made.
Connections to the structure must remain mechanically secure and
electrically conductive.
Wire should be installed with slack. Damage to insulation should be
avoided, and repairs should be made if damage occurs. Test leads should
not be exposed to excessive heat or sunlight.
Thermite (Exothermic) Welding
The most common method of attaching wires and cables to a structure is by
exothermic welding, also known as thermite welding. This process uses a
graphite mold into which is poured a charge-containing mixture of copper
alloy and magnesium starting powder as shown in Figure 8.12. The mixture
is ignited with a flint gun, melts, and drops down, welding the wire to the
structure.
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