The best advice is not to take any risks were post-tensioning is involved. Severing a tendon is extraordinarily dangerous and destructive, not just for your jobsite, but for anything in the firing line after the taut cable snaps. The load capacity can be critically reduced by a damaged tendon; a problem which may only become apparent once the building if fully built-out and inhabited. Although the unmistakable booming noise of a snapped PT cable was not heard, the architects and contractors took pride in the quality of their work, and so they decided to survey the post-tensioning cables for even minor damage anyway.
To prevent their precautionary measure from delaying progress, the detection system needed to be fast and provide reliable, very precise data. The tool of choice was the Hilti PS 1000 X-Scan detection system. First, the X-Scan was used to detect the exact location of the tendons and to find indicate the cover depth. This scan data was then compared with the depth of the drilled holes, to see if the tendon was at the same depth and if it were possible that the tendon could have been hit. The results showed that none of the PT cables had been damaged during the drilling. Work could continue without further delay.