DID YOU KNOW
Stud finder apps make use of modern smartphones’ magnetometer sensor to pinpoint the exact location of wall studs. A magnetometer detects the nails, screws, and joists that act as fasteners for studs. Besides functioning as an alternative magnetic metal detector, the sensor is also used for compass apps in phones. It works by measuring magnetic fields and can determine the device’s orientation in relation to the magnetic north. It is also used with the accelerometer and the GPS unit to determine the device’s position. It is through the magnetometer that digital maps are auto-rotated based on orientation. Meanwhile, the accelerometer determines movement and the GPS determines position.
Since navigation became an essential feature for smartphones, magnetometers have also become a mandatory component. As with most of the trends in technology, magnetometers for phones have become smaller and cheaper, but more powerful and efficient. The price of a magnetometer has gone down from $1.50 per device to below $0.50, as production volumes have increased. In 2008, only 8.7 million phone units were manufactured with magnetometer sensors. The numbers were estimated to be 540 million in 2013. In 2017, 1.54 billion units were sold worldwide, with most of them containing magnetometer sensors.