TomTom Runner 3 Manuel D'utilisation page 57

When you have connected to your sensor once, your watch always reconnects to your sensor.
When the chainring icon has stopped flashing, your watch is ready to measure your speed and
cadence. You can start cycling with no GPS fix but for proper GPS tracking, wait until the GPS
icon has also stopped flashing before you start your cycling activity.
Tip: When you are using the Cadence & Speed Sensor for cycling activities, you are warned when
no speed data is being received from the sensor.
While you train, you can choose to show your current cadence or change the display to see your
cadence.
You can also use a training program
You can also use the Cadence & Speed Sensor with other Bluetooth® Smart Ready devices and apps.
See the documentation that comes with your product or app for more information.
To change the CR2032 battery on the sensor, use a coin to open the back of the sensor. The battery
must be recycled or disposed of properly according to local laws and regulations.
to train to a target cadence zone.
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