We had a leak in a brine system at a rink in the poured concrete. Tried high pressure air, nitrogen, dyed water, no luck. Bought an ultrasonic, and were confident enough to open up a patch near the header trench about fifteen feet off the boards. opened up a hole three feet square and found leaks there after locating with ultrasonic. 500 dollar investment saved tons of money, and allowed us to complete the repair quickly and get them repoened on time. In this case it worked, AFTER we realized the flourescent lights had to be turned off. man what a racket that sheet makes.
