Wall Scanner & Metal Detector

A wall scanner and metal detector that uses your phone's magnetometer to find iron studs, steel pipes, wires, and rebar behind drywall. Hold the phone near a wall and it shows the magnetic field strength in real microtesla. When iron or steel is nearby, the field bends and you see exactly how much.

USES

* Find iron studs and steel framing before drilling
* Locate iron pipes and rebar in walls and concrete
* Spot nails, screws, bolts, hidden hardware
* Detect keys, buckles, magnets, metal tools
* Measure electromagnetic fields from motors, microwaves, transformers

WHAT IT CANNOT DETECT

The phone magnetometer reacts only to ferromagnetic materials: iron, steel, nickel. It cannot find:

* Gold, silver, copper, aluminium, brass — non-ferrous, no magnetic signal
* Plastic, wood, glass, ceramic
* Buried objects more than 5 to 25 cm away — phone magnetometer reach is limited

These limits come from how magnetometer sensors work. They detect changes in magnetic field strength, which only ferromagnetic metals produce.

DETECTION MODES

* Stud Finder — wall scanning, threshold 6 microtesla, continuous tone
* Metal Finder — general use, threshold 10 microtesla, fast response
* EMF Scanner — weak field detection with X/Y/Z axis readout
* Raw Data — full debug magnetometer output for makers, students, physicists

FEATURES

* Live magnetic field readout in microtesla
* Figure-8 calibration with hard-iron and soft-iron correction
* Adjustable sensitivity per mode
* Audio beep and haptic vibration alert on detection
* Session recording with full graph view
* CSV export of magnetometer data
* X/Y/Z axis debug readout for raw sensor analysis
* Saturation warning for magnetic phone cases
* Reference values for common objects and the Earth's magnetic field
* Dark mode and full accessibility support including VoiceOver

HOW IT WORKS

Every modern iPhone has a built-in magnetometer chip — the same sensor that powers your Compass app. It reads the Earth's magnetic field, about 49 microtesla in central Europe. When iron or steel comes close, the field bends. MetalHunt shows you exactly how much, in real time, with a smoothed display and proper figure-8 calibration. Aluminium, copper, gold, and silver do not bend a magnetic field — that is a property of the materials, not a software limitation.