When assessing corrosion in Pipecheck, the 1st step before scanning is to clean and free the surface of any coating, dust or corrosion scale. This is done to reveal only the remaining good material. In some cases, it is not possible to remove everything prior to scanning (like arc strike near a weld for example), or sometimes small pieces of coating or corrosion scale are left.
In these cases, Pipecheck features editing tools that makes it possible to pursue the analysis even if small artefacts are left in the scanned data. Please note that when analysing a large area, it might be difficult to find those small artefacts just by looking at the scanned surface.
The user can go over the surface and check square inch per square inch, but on large areas it would be a long task. To help the user in this task, the user can run a 1st analysis once most of the editing has been done. Then, by looking at the resulting color map, it will become easier to spot the small artefacts left behind. They will leave colored lines on both sides of it, as if there was corrosion right next to it. In fact, it just the virtual pit gauge that is sitting on that higher point and measure deeper point right next to it.
Now that it has been spotted, it can be removed and re-analysed for more accurate measurements.
The same goes to validate that all the surface of the weld has been selected and tagged as an excluded area. If some surface on the weld hasn’t been selected, it will leave a high point where the virtual pit gauge will sit. This will result in measures with deeper depths than actual value. These measures are starting at half of the length of the smallest pit gauge, starting from the excluded area. Inside this range from the excluded area to half the length of the smallest pit gauge, depth measurements will not be affected because that is where Pipecheck will measure depth with a one-sided pit gauge, hence not sitting on those high points from the weld.
Taking a closer look to validate that it is not corrosion and some surface of the weld is left, the excluded area can be enlarged to be re-analyzed.
