Civil Engineering Reference
In-Depth Information
TABLE 21-5. (
Continued
)
Equipment
Requirements
Name
Data Form
Operating Principle
Applications
Precision
References
Electrochemical im-
pedance spectros-
copy (EIS)
Impedance spectrum
(102 -107 Hz)
Polarization fre-
quency response
of impressed AC
yields impedance
spectrum
Corrosion rate
Electrical model of
corrosion surface
Coating effective-
ness
Interpretation of
model accuracy is
controversial
Polarization cell
Potentiostat
Frequency analyzer
Data interpretation
software
32, 33, 34
Package cost:
$25,000
Electrochemical
noise
Low-frequency
changes in freely
corroding surface
potential
Localized corrosion
events emit a
base signal char-
acteristic of the
magnitude and
type of corrosion
process
Remains a research
tool
Unproven
Galvanic coupling
cell
Frequency analyzer
Zero-resistance
ampmeter
35, 36
Package cost:
$20,000
(Reprinted from
Internal Corrosion of Water Distribution Systems,
2d ed., by permission. Copyright
1996, American Water Works Association.)
