Can the Versa 4's heart rate monitoring be calibrated or adjusted manually

1. Proper Fit: Ensure the watch is worn correctly on your wrist. It should be snug but not too tight, with the sensor (green LED light) in contact with your skin. Moving the band higher on your wrist during workouts can help improve accuracy[5][7].

2. Skin Contact: Tattoos or other skin conditions might interfere with the sensor's ability to read heart rate accurately. If you have tattoos, try wearing the watch on an area without tattoos[9].

3. Restart or Reset: If the heart rate monitor is malfunctioning, restarting the device can resolve the issue. For persistent problems, a factory reset might be necessary, though this will erase unsynced data[3][9].

4. Update Software: Ensure your device is running the latest software. Some users have reported changes in heart rate tracking accuracy after updates, possibly due to new algorithms[10].

5. Check Battery Level: A low battery can affect heart rate monitoring accuracy. Charging the device may resolve issues related to low power[7].

6. Use Correct Bands: Ensure you're using bands that fit well and allow the sensor to maintain contact with your skin. Some third-party bands might not provide the necessary fit for accurate readings[7].

7. Relax and Stay Still: If the heart rate reading is not appearing, try relaxing your wrist and staying still for a few seconds[2].

While these steps can improve accuracy, they do not constitute manual calibration. Fitbit's heart rate zones are personalized based on your maximum heart rate and resting heart rate, which are calculated automatically by the device[4].