NACE Corrosion Monitoring Techniques 3

Question 1

Multielectrode array (MEA) sensors are particularly well suited for detecting which type of corrosion?

Accepted Answer

Localized corrosion such as pitting by measuring non-uniform current distribution between electrodes

Answer

MEA sensors detect non-uniform current distribution between multiple closely spaced electrodes, which is the characteristic electrochemical signature of localized corrosion events such as pitting.

Question 2

In a risk-based corrosion monitoring program, monitoring locations are selected based primarily on:

Accepted Answer

Risk assessment combining probability of corrosion occurrence and consequence of failure

Answer

Risk-based monitoring prioritizes locations where high corrosion likelihood combined with high failure consequence creates the greatest overall risk, optimizing resource allocation and safety outcomes.

Question 3

A negative shift in free corrosion potential (Ecorr) during monitoring of a steel structure typically indicates:

Accepted Answer

Increased anodic activity suggesting higher corrosion rate or active corrosion onset

Answer

A negative (more active) shift in Ecorr typically reflects increased anodic dissolution activity, indicating potentially higher corrosion rates or the initiation of localized corrosion.

Question 4

Radiographic inspection (RT) used as a corrosion assessment tool is best described as:

Accepted Answer

A periodic, non-destructive offline method providing cross-sectional images revealing internal wall loss

Answer

RT is a periodic, non-destructive examination method that uses X-ray or gamma-ray imaging to reveal internal corrosion, wall thinning, and volumetric defects without removing the pipe from service.

Question 5

Microbiologically Influenced Corrosion (MIC) is most effectively monitored by:

Accepted Answer

Combining microbiological sampling, corrosion rate measurement, and biocide effectiveness evaluation

Answer

Effective MIC monitoring requires identifying and quantifying microbial populations (SRB, APB, etc.), correlating microbial activity with corrosion rate data, and assessing biocide treatment performance.

NACE - National Association of Corrosion Engineers Certification Practice Test

NACE - National Association of Corrosion Engineers Certification Practice Test

NACE Corrosion Monitoring Techniques 3