The changes then highlight, that we move away from a conductivity test to the Ion Detection Tube analysis utilizing the sleeve extraction methods, which measures chloride ions more specifically.
The updated ISO8502-6 and ISO8502-9 standards recognize that an erroneous reading is possible by the irrelevant contribution of carbonates, bi-carbonates and hydroxides.
Alternative test methods such as ISO 8502-5 and the new ISO 8502-15, which provide accurate instructions to obtain results for ion specific contamination, should now be the used as the primary surface preparation test method to ensure optimum coating protection.
More on the Ion Specific test which uses ion detection tubes. The results from this in-field test method have been found to be more accurate.
Compared to the solubilization method, we found that this method provides surface chloride measurements that were not only within specification, but also vastly different from the conductivity or conductometric readings – which includes calcium carbonates, bicarbonates and hydroxides as corrosive elements.
Therefore, the latest ISO standards would have cleared up most of the misconceptions. We see that most specifications have an allowable tolerance of surface chlorides in the upper range that can be easily met through the normal use of the Ion detection tube & sleeve test method.
The update is a recognition that technology has changed since the Bresle method was introduced, with measurement tools now available that provide Ion specific testing to specify an abrasive that provides maximum coating protection.