FieldSweep: Magnetic Field LogSupport
Questions about Magnetic Field Log? Start here. If you need further help, get in touch.
Why is the value blank or not showing?
Your iPhone needs calibration before it can read the magnetic field. Slowly rotate your device in a figure-8 pattern about three times to calibrate the magnetometer. The value will appear once calibration is complete.
Why does the reading change so much?
Magnetic fields vary near metal objects. Steel desks, speaker magnets, ferrous construction materials, and electronic devices all affect the local field. Move away from large metal structures or speakers to get more stable readings.
I measured outdoors and got 25–65 µT. Is that normal?
Yes. That is Earth's natural magnetic field. The strength of the planet's magnetic field ranges globally from about 25 to 65 microtesla. Your reading is working correctly.
Can this app measure radio waves, Wi-Fi, or 5G?
No. iPhone contains a magnetometer that measures only magnetic fields (magnetic flux density). It does not have sensors for electric fields or electromagnetic waves. This app measures magnetic field only.
Where is my data stored?
All recordings are saved on your iPhone only. No data is sent to any server, to Netflowers, or to any third party. Everything stays on your device.
If I get a new iPhone, will my records transfer?
No. Because the app stores data only on your device and does not use iCloud or any sync service, records will not move to a new iPhone. You can use the app on multiple devices, but each has its own separate data.