The CORE sensor is like any other sensor, set it up once and it automatically connects. For sports use, ensure that you have also paired your heart rate monitor with your CORE.
The Suunto (December 2022) Firmware version 2.23.20 allows all Suunto 9 watches to connect to the CORE sensor
STEP 1 - Pair Heart Rate Monitor
Pair your Heart Rate Monitor to your CORE. This is essential for using the CORE sensor for sports for the best accuracy. The CORE is paired with the CORE App to an ANT+ heart rate monitor and at this stage does not pair to the Bluetooth heart rate monitor on Suunto watches.
Step 2 - Install the SuuntoPlus CORE App
A. Use the Suunto App and connect to the Suunto watch
B. Inside the App, open the SuuntoPlus Store.
C. Locate and install the CORE App onto your watch
Setup is now complete
Getting CORE data into workouts
Suunto watches require a the CORE sensor to be selected before each workout and the real-time core temperature data will be available as a watch face during activities.
To begin an activity with CORE sensor data
1 - Choose the activity (e.g. Cycling, Running)
2 - Before starting, scroll down to Options
3 - Select Sports Apps
4 - Select CORE (it searches for your CORE sensor)
5 - Once connected, you are returned to the previous menu
If it does not find the CORE, there is an option to retry
6 - You can now begin your activity
Realtime CORE data is displayed on a watch face and the additional 'temperature trend' information that indicates if the core body temperature is increasing / decreasing.
Suunto set-up tips
The core body temperature data is available real-time, though on Suunto watches is not recorded to the FIT file.
The CORE sensor and Suunto watches connect via bluetooth. The CORE sensor allows two simultaneous bluetooth connections (for example, the COROS sensor can connect to the CORE App and the Suunto watch).
In the case the CORE sensor is not identified, it could be connected to another device. Disconnect or turn off the bluetooth for those to 'release' this connection.