How to Measure
Anyone with a smartphone can contribute. Follow these four steps to capture a reading and add it to the atlas.
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How to take a measurement
Anyone with a smartphone can contribute. Follow these four steps to capture a reading and add it to the atlas.
- 1
Install a free sensor app
Download a free magnetometer app such as Physics Toolbox Sensor Suite or phyphox on your phone.
- 2
Measure with the magnetometer
Open the magnetometer and hold your phone flat, away from metal, electronics, and magnets.
- 3
Note the total field strength
Read the total magnetic-field strength in microtesla (µT) — a typical reading is 25–65 µT.
- 4
Submit your value and location
Enter the reading and your location on OpenMag so it joins the community atlas.
Submit your first measurementNo account needed — just a reading and a location.