1. Check if your phone requires a software update: Settings > System > System update.
2. If your phone has been in contact with VOC, check that the sensor ports below the volume buttons on the side of your phone are clear. If not, flush with water then allow the device to dry and re-calibrate.
Note: Calibration can take up to 12 hours.
If your phone is new: Remove the sticker covering the sensor ports and allow 36 hours for your phone to calibrate.
Note: Your phone can be used as normal during this period.