National Association of Corrosion Engineers (NACE)
Status
Scope
Assessment of corrosion in the field is complex due to the
wide variety of applications, process conditions, and fluid
phases that exist in industrial plants where corrosion occurs.
A wide range of direct and indirect measurement techniques
is available, but each technique has its strengths and
weaknesses. In some applications certain techniques
cannot be used at all. Some techniques can be used online,
while others are done off-line. Commonly more than
one technique is used so that the weaknesses of one are
compensated for by the strengths of another. In other
cases, a combination of different techniques can be synergistic,
such as process sampling along with detection of a
corrosion upset.
The purpose of this technical committee report is to
analyze the various techniques with respect to their benefits
and limitations across the wide spectrum of industries in
which they are employed. One technique, such as pH
measurement, has considerably different features depending
on the industry and environment in which it is used.
Input to this report has been taken from as wide a spectrum
of experienced field users as possible.
This report is intended as a practical reference for both
new and experienced users. For new users, it will assist in
providing an understanding of the practical aspects of each
technique. For experienced users, it will be helpful in
assessing less commonly used techniques, or the implications
of using a familiar technique in a totally different
operating environment.
There are several ways in which the many techniques
can be subdivided. Here the categories have been selected
on the following basis:
Direct Techniques — Intrusive
— Nonintrusive
Indirect Techniques — On-Line
— Off-Line