The video has 2 problems:
-
backwards grease pen writing is tedious and annoying
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there is no way to tell if the black cylinder under the tile is a hollow pipe during the D30 tests. It seems like there would be no reason to hide this, other than to falsify the results by substituting a solid cylinder for the pipe section shown in other tests.
D30 might be all that it claims, but the video is not convincing.
