Observation of the Magnetic Field using a Smartphone

Abstract

When measuring the magnetic field using a sensor in a smartphone, one can choose from several applications [1–3] with useful graphical interfaces. For my first endeavor, I tried to locate the magnetic field sensor (MFS) in my smartphone SC-04D. I was able to find plenty of pictures on the internet of my phone dismantled, but none of them helped me locate the MFS. I did not want to risk dismantling my own phone, so I used a piece of weakly magnetized iron and found a point where the magnetic field reading was the highest (188 μT) with the application Sensor Box for Android [4]. I then assumed the sensor was just below the surface of that point (Fig. 60.1). In an earlier paper [5], Silva introduced readers to the app 3D Compass and Magnetometer [6] and “Relative Mode,” which can be used to “zero out” background noise such as geomagnetism. Some [7] similar applications available record data that can be exported as a CSV file and can be analyzed using MS Excel or other spreadsheet programs.