Nace CP 1 - Demonstration of Cathodic Interference

Stray Current Interference 6:9
CP 1 – Cathodic Protection Tester Course Manual
© NACE International, 2000
02/01/05
Experiment 6.1 — Demonstration of Cathodic
Interference
V
A
B
C
V
DE
F
+
_
9 VDC
Impressed
Current Anode
Steel
Sheet
Foreign Steel Rod
Procedure
1. Set up the experiment as shown above without the steel rod (foreign
structure).
2. Measure and record potentials on cathodically protected structure, the
steel sheet, at positions A, B, and C.
3. Disconnect cathodic protection system.
4. Place the steel rod (foreign structure) in the water in the tray, as shown.
5. Measure and record potentials on the foreign structure at reference
electrode positions D, E, and F.
6. Connect cathodic protection system.
7. Repeat Step 5.
8. Repeat Step 2.