Cathodic Protection Technician
Certification Exam Practice Questions
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Plus Rationale 2026 Q&A| Instant
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48. During an impressed current cathodic protection (ICCP) system
performance evaluation on a buried steel pipeline, a Cathodic
Protection Technician observes that the structure-to-electrolyte
potential measured with a calibrated copper/copper sulfate reference
electrode is -790 mV with the cathodic protection system energized
and shifts to -710 mV immediately after the current is interrupted.
Based on accepted cathodic protection criteria and proper
interpretation of instant-off measurements, which of the following is
the most appropriate conclusion?
,A. The pipeline is adequately protected because the energized potential is
more negative than -850 mV.
B. The pipeline may not satisfy the -850 mV instant-off criterion because
the polarized (instant-off) potential is only -710 mV, indicating additional
evaluation or adjustment may be required.
C. The pipeline is overprotected because the instant-off potential is less
negative than the energized potential.
D. The reference electrode is defective because instant-off potentials should
always be more negative than energized potentials.
Rationale: Instant-off potential removes most of the IR drop from the
measurement and provides a better indication of true polarization. Since
the instant-off potential is -710 mV, it does not satisfy the commonly
applied -850 mV polarized potential criterion when that criterion is being
used. Additional evaluation, such as applying alternative criteria or
adjusting system output if appropriate, may be necessary before
concluding that adequate cathodic protection exists.
49. A Cathodic Protection Technician is evaluating the effectiveness
of a sacrificial anode system installed on a buried steel water pipeline.
The measured pipe-to-soil potential has become progressively less
negative over several years despite no known damage to the pipeline
coating. Which of the following is the most likely explanation for this
gradual loss of cathodic protection effectiveness?
, A. Increased polarization of the pipeline.
B. Decreased soil resistivity caused by heavy rainfall.
C. Consumption of the galvanic anodes resulting in reduced current output.
D. Improved coating efficiency causing lower protective current demand.
Rationale: Galvanic anodes gradually corrode while supplying protective
current. As they are consumed, their ability to deliver sufficient current
decreases, causing the protected structure potential to become less
negative unless replacement anodes are installed.
50. During a close-interval potential survey (CIPS), why is the current
interrupter synchronized between multiple rectifiers protecting the
same pipeline?
A. To increase rectifier voltage output.
B. To eliminate stray current corrosion.
C. To obtain accurate instant-off potentials by interrupting all cathodic
protection current sources simultaneously.
D. To reduce coating resistance.
Rationale: When multiple rectifiers influence the same structure, they must
interrupt simultaneously to remove all cathodic protection current during
the instant-off measurement. Otherwise, residual current from operating
rectifiers produces inaccurate polarized potentials.
Certification Exam Practice Questions
And Correct Answers (Verified Answers)
Plus Rationale 2026 Q&A| Instant
Download Pdf
48. During an impressed current cathodic protection (ICCP) system
performance evaluation on a buried steel pipeline, a Cathodic
Protection Technician observes that the structure-to-electrolyte
potential measured with a calibrated copper/copper sulfate reference
electrode is -790 mV with the cathodic protection system energized
and shifts to -710 mV immediately after the current is interrupted.
Based on accepted cathodic protection criteria and proper
interpretation of instant-off measurements, which of the following is
the most appropriate conclusion?
,A. The pipeline is adequately protected because the energized potential is
more negative than -850 mV.
B. The pipeline may not satisfy the -850 mV instant-off criterion because
the polarized (instant-off) potential is only -710 mV, indicating additional
evaluation or adjustment may be required.
C. The pipeline is overprotected because the instant-off potential is less
negative than the energized potential.
D. The reference electrode is defective because instant-off potentials should
always be more negative than energized potentials.
Rationale: Instant-off potential removes most of the IR drop from the
measurement and provides a better indication of true polarization. Since
the instant-off potential is -710 mV, it does not satisfy the commonly
applied -850 mV polarized potential criterion when that criterion is being
used. Additional evaluation, such as applying alternative criteria or
adjusting system output if appropriate, may be necessary before
concluding that adequate cathodic protection exists.
49. A Cathodic Protection Technician is evaluating the effectiveness
of a sacrificial anode system installed on a buried steel water pipeline.
The measured pipe-to-soil potential has become progressively less
negative over several years despite no known damage to the pipeline
coating. Which of the following is the most likely explanation for this
gradual loss of cathodic protection effectiveness?
, A. Increased polarization of the pipeline.
B. Decreased soil resistivity caused by heavy rainfall.
C. Consumption of the galvanic anodes resulting in reduced current output.
D. Improved coating efficiency causing lower protective current demand.
Rationale: Galvanic anodes gradually corrode while supplying protective
current. As they are consumed, their ability to deliver sufficient current
decreases, causing the protected structure potential to become less
negative unless replacement anodes are installed.
50. During a close-interval potential survey (CIPS), why is the current
interrupter synchronized between multiple rectifiers protecting the
same pipeline?
A. To increase rectifier voltage output.
B. To eliminate stray current corrosion.
C. To obtain accurate instant-off potentials by interrupting all cathodic
protection current sources simultaneously.
D. To reduce coating resistance.
Rationale: When multiple rectifiers influence the same structure, they must
interrupt simultaneously to remove all cathodic protection current during
the instant-off measurement. Otherwise, residual current from operating
rectifiers produces inaccurate polarized potentials.
