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This is where the surface preparation grades such as Sa 2 ½, roughness or, for example, the Bresle test come into play. Literally, ISO 12944 states: "The requirements for monitoring these aspects of work, the frequency of assessment and the place of assessment must be agreed between the contracting parties involved." This statement is very helpful for an unclouded business relationship, because it means, mutatis mutandis, "Agree among yourselves who will inspect what, how, and when, and what the results should be - and then put it all down on paper." What is needed is nothing other than an ITP, an "inspection and test plan", i.e. a document that coordinates monitoring. With regard to health protection, occupational safety and environmental protection, the standard gives an indication that these must be complied with. If ISO 12944 is required by the customer, he has the right to check and demand these aspects as well. For the storage of coating materials, a temperature of +3° C to +30° C is specified, unless otherwise permitted. If temperatures must be maintained, it seems natural that they should also be measured and recorded - using maintained and calibrated measuring equipment, even if this involves additional cost and effort. At the same time, neither the delivery nor the transport to the construction site should be lost sight of. But in daily practice, this is far from common or even normal. From the length, you as a reader have now read about half of the article - and only now will it finally be about the execution of the coating. This definitely has parallels to the real process of corrosion protection, because in real life, too, the preparation is at least as important as the actual application.

This paragraph begins with a very relevant and, again, self-evident-sounding specification: "Surfaces to be treated must be safe to reach and well illuminated." At first, this sounds little irritating, but as is so often the case, different parties, especially buyers, can understand this sentence quite differently. Here, it is advisable to agree and record in writing how the component is to be reached and, above all, what exactly "bright" means. The advantage of this context is that illuminance can be measured relatively simply - but here, too, measurement, calibration and maintenance are essential if the results are to be of any value. For coating thickness measurement, Part 7 refers exclusively to ISO 19840, unless otherwise agreed. This means that unless otherwise agreed in writing at the start of the project, a correction value, usually 25 µm, must be deducted from each coating thickness measurement. In addition, the 80/20 rule automatically applies. It should also be noted that the standards section requires a wet film thickness measurement. In this case, the dew point distance of the surface must be 3° C. The dew point results from the air temperature and the relative humidity. In addition, the component temperature must be measured. This must be above the dew point temperature. Measuring and testing, including calibration, is an elementary part of the corrosion protection design, in addition to the process instructions and surface preparation. After a few more paragraphs on application procedures, the standard turns to monitoring: "The execution of the work must be monitored in all phases. Supervision must be carried out by appropriately qualified and experienced personnel." The term in all phases must be taken literally. Here it should be remembered that corrosion protection does not begin with blasting. There is a cleaning and testing of the degree of preparation, for example, P3, climate data and so on.

When it comes to "qualified and experienced personnel", there is already more need for definition. Here it is easiest to rely on one of the generally known certifications such as Frosio, NACE, DIN Certco or similar. Nevertheless, it is very helpful to agree on the qualification and the degree of qualification with the customer in advance. Regarding measuring devices and their condition, the standard says the following: "The instructions of the measuring device manufacturer for the use of his devices must be followed. Measuring instruments in use shall be regularly tested, calibrated, and maintained, and the results shall be recorded." Here, calibration is not to be confused with adjustment. Calibration is the deviation of a measuring instrument from a standard. Generally, calibrations are performed by calibration laboratories. Adjustment is simply the setting of a display. This can be easily explained using the example of a coating thickness measurement. In order to set or adjust such a measuring device, test foils are used. Without this adjustment, a coating thickness gauge would be as useful as a thermometer without a scale. With the help of these foils, a scale and a measuring range are applied. This implies that what is written on the foils should be correct. To ensure this in turn, such test foils need to be calibrated - so a laboratory needs to confirm the specified thicknesses of the test foils. Of course, it may also be a good idea to have the gauge and its associated probe calibrated in a laboratory. When performing such calibrations independently, those responsible should carefully consider the requirements and regulations that a professional laboratory must adhere to. When assessing the coating, the standards section describes non-destructive or destructive tests. No specific tests are specified here; reference is simply made to the specification. It is therefore important to agree in advance what will be tested and how. Finally, the handling of control surfaces and specimens is described, but the execution is not required. This was a brief and concentrated summary of the relevant pages of Part 7 of ISO 12944. Overall, this article offers a somewhat different perspective on this widely known standard and, above all, on the need to make concrete agreements in those areas where it is open to interpretation, in order to protect contractors and clients from ambiguity and unnecessary complaints.

Author: Martin Czysch Frosio Level III SLV Duisburg

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