Application
Corrosion mapping
Image subsurface corrosion creep through an intact coating and measure it against ISO 12944, with no sectioning and no coating removal.
The challenge
The failure mode surface methods miss
Corrosion under a coating is the failure mode that matters most in coatings work, and the one standard tools struggle to see early. ISO 12944 evaluation depends on scribe creep measurement, which traditionally means removing the coating, with all the variability and time cost that entails, before considering replicate counts and calendar pressure on test programmes.
A 2D map of corrosion under an intact coating
Chameleon images corrosion underneath an intact coating and produces a 2D map of the affected area that can be measured against ISO 12944 creep criteria. Because the coating stays on the sample, you can detect corrosion onset earlier in the test, follow the same test coupon over time, and reach a decision with fewer replicates, freeing capacity to evaluate more candidates per cycle.
The measurement reaches the corrosion because terahertz passes through the organic coating and reflects off the steel beneath it, the same signal path used for coating thickness measurement and explained in how terahertz thickness measurement works. Acquisition, scan patterns, and the exported map are covered on the Chameleon product page.
What it changes in practice
Creep is detectable under the coating before it breaks the surface.
Repeat measurement replaces destructive evaluation.
A lower replicate burden frees programme capacity.
ISO 12944 scribe creep visible without removing the coating
A map of subsurface corrosion creep along an ISO 12944 scribe, with the affected area extractable directly from the image. The coating is not removed, the coupon is not destroyed, and the same sample can be re-measured at later time points to track progression.
