Magnetometer: EMF & Metal

Magnetometer+ turns your iPhone into a precise magnetic field meter with three purpose-built modes — and now keeps a full history of every reading.

THREE MODES

• Auto — radial gauge with raw total field magnitude.

• Earth Field — total field with latitude band (low / normal / elevated / high).

• Metal Detector — baseline-calibrated detection with intensity verdict (no metal / weak / detected / strong / large) and live haptic feedback.

WHAT'S NEW

• ⌖ Zero Calibration — capture your environment's device-internal field bias as the 0 reference, so subsequent readings show only deviation. Just like a real metal detector.

• Haptic Feedback — Metal mode pulses faster and stronger as you approach ferrous objects. Toggle on/off from main screen.

• Unit Toggle — switch between µT, mT and Gauss with a single tap.

• GPS Tagging — optionally tag saved measurements with location coordinates.

• Measurement History — every reading is auto-saved with a 7-day trend chart and insights like "+12% vs your 7-day average".

• Notes & Favorites — add a note ("wall stud", "buried pipe") and star to any saved reading.

• Compare Mode — pick two saved readings and view the difference side by side.

• Share Result — share your current reading as an image.

• CSV Export — share all your measurements as CSV for spreadsheets.

CORE FEATURES

• Real-time 3-axis magnetic field measurement

• Kalman-smoothed sensor readings

• Min/Max/Avg/Peak tracking with elapsed time

• Sensitivity adjustment 0.5x – 2.0x

• Total field magnitude + per-axis components

• Reference library: Earth field bands, metal intensity classes

HONEST TECH NOTE

iPhone magnetometers are uncalibrated and include device-internal bias (~300–450 µT from speaker / motor / battery magnets). The ⌖ Zero button captures that bias so subsequent readings reflect only field changes in your environment — same workflow as a physical metal detector.

FOR HOBBYISTS · DIY · STUD FINDING · TREASURE HUNTING · CABLE DETECTION · EDUCATION

Available in 14 languages.