A signal loss alarm* notifies you when the FreeStyle Libre 3 sensor has not communicated with the FreeStyle Libre 3 app** for 20 minutes. Signal loss could be caused by the sensor being too far away from your smartphone (over 33 feet), Bluetooth is turned off, or another issue such as an error or problem with your sensor.
* Notifications will only be received when alarms are turned on and the sensor is within 33 feet of the phone. You must have Critical Alerts enabled to receive alarms and alerts on your smartphone.
** The FreeStyle Libre 3 app is only compatible with certain mobile devices and operating systems. Please check our compatibility guide for more information about device compatibility before using the app.