4
E
n
g
li
s
h
concentrations of sodium chloride solution and the known surface area
sampled, to give surface salt levels in µg.cm
-2
.
Figure 1. Elcometer 130 SCM400 Salt Contamination Meter
3 SPECIFICATION OF SALT LEVELS
Ideally, the salt level remaining on a steel surface after surface cleaning and
prior to painting or any other construction operation, should be zero.
In practice it is not possible to achieve this due to various environmental factors
and a working salt level needs to be specified. In the case of painting, this level
is a matter for discussion between the Client, the Applicator and the Paint
Manufacturer and it will depend on the working conditions, the paint system
used, the required service life and what can be economically achieved.
Consequently, it is not possible to specify in these Operating Instructions which
salt standards are best suited to all industries. However, during the
development of the Elcometer 130 SCM400, the effect of salt contamination on
the life of coatings under a range of realistic and accelerated environmental
conditions for a number of common generic coating systems was assessed.
