Review on 🔍 Stud Finder Wall Scanner: Upgraded Smart 5-in-1 Multi-function Sensor for Metal, Studs, AC Wire, and Pipe Locator in Walls by Doug Hawkins

Calibration is easy: just hold the scanner vertically against a wall for a few seconds until the vertical stripes disappear. Now start slowly scanning left or right without touching the button on the side. When it reaches the hairpin, it will start beeping but will continue to slow down. About then he finds the middle of the hairpin. Mark the center and pause, let it calibrate again for a few seconds, then move on to the next post. I bought it to find joists on the side of the roof in the attic for installing solar panels. good tool.