I learned the hard way what to do after plumbers made several saw cuts in a slab after my sensors were placed. They flooded 3 out of 12 sensors and trashed them. Ever since then, after getting my initial readings, I cover every sensor with the supplied stainless steel caps, then install the orange caps with a bead of caulk. I top it all off with bright colored tape labeled "DO NOT DISTURB". Have had no problems since. However, even with all that, if the concrete get shot blasted or ground, stuff can still get in sometimes.
Concrete Restoration Services, LLC