1. Check if the device requires a SW update, settings -> scroll down to System -> System update, this will check for the latest version SW that the device should be on.
2. If the device has been in contact with VOC check that the sensor ports below the volume buttons on the side of the device are clear, flush with water. Allow the device to dry and re-calibrate this can take up to 12 hours.
If the device is new:
Remove the sticker covering the sensor ports, allow the device 12 hours to calibrate (device can be used as normal during this period).