EPA NWCA vs Stud Finder Pro

National Wetland Condition Assessment field collection app.

Measure twice. Drill once. Stud Finder Pro turns your iPhone's built-in magnetometer into a precision wall scanner, the same sensor that powers your compass, calibrated to find the nails and screws inside drywall, plaster, and lath. Take the case off. Hold the top of your phone flat to the wall. Slide slowly. The signal climbs as you cross a screw, peaks dead-center, and drops on the other side. Mark the peak. That is your stud. Built for the moment between picking up the drill and committing to the hole. WHAT'S INSIDE A real-time magnetic-field readout in microteslas. A clean amber arc gauge that sweeps from idle to peak as you cross metal. Audio feedback that climbs with the signal so you can scan without watching the screen. Haptic confirmation at peak. A two-second auto-calibration that zeros out the room before you start. THE WAY IT WORKS Your iPhone has a magnetometer near the top edge, the same sensor your compass app uses. Stud Finder Pro reads it forty times a second, watches for spikes against your calibrated baseline, and shows you exactly where the metal is. Wood studs themselves are not magnetic, but the screws and nails that fasten drywall to them are. Find the screw. The stud is centered around it. HOW TO GET ACCURATE READINGS Remove your phone case. Magnetic accessories, metal-rich cases, and watches all skew the magnetometer. Hold the top edge of your phone flat against the wall. Slide slowly and steadily. Calibrate first by holding still for two seconds in an open area away from metal. WORKS ON Drywall, plaster, lath, and most painted wall surfaces. Concrete walls with rebar register strong signals everywhere, which is not what the app is for. DOES NOT DETECT Wood directly. Plastic pipes. Live electrical current. Non-magnetic metals like copper or aluminum. This is a ferromagnetic detector, not an X-ray. OFFLINE-FIRST PRIVACY No accounts. No advertising trackers. The magnetometer data never leaves your device. Anonymous usage analytics through TelemetryDeck only, no personal identifiers, no cross-app tracking. PRO TOOLKIT Pro unlocks unlimited scans, calibration memory, and the full-precision experience without any session limits. One payment, yours forever. Terms of Use: https://cmlapps.github.io/studfinder/terms.html Privacy Policy: https://cmlapps.github.io/studfinder/privacy.html Support: https://cmlapps.github.io/studfinder/support.html