You have no heart rate data

The full history of your heart rate measurement is available in the Withings App. Click here for more information.
 

Your heart rate data seems inaccurate

If your heart rate data seems inaccurate or if you get different results than you do with a heart rate monitor, perform the following steps:

1. Make sure your ScanWatch 2 is properly positioned on your non-dominant wrist, 1 cm from the wrist bone.
   
2. Make sure you wear your ScanWatch 2 tightly enough. It shouldn't be able to move around your wrist.
   Note: You may notice inaccurate heart rate data if you wear a metal or leather wristband.
3. Make sure you've launched the continuous heart rate mode before starting your activity.
   It can take up to 20 seconds for the first heart rate measurement to be displayed on your watch.
4. Make sure the sensor below your watch emits a blinking green light when the watch display is on.
5. Make sure your watch is clean and your wrist is moisturized but not sweaty or overly wet. 
   Note: Excessively dry skin may result in repeated failed recordings. If necessary, wash and lightly dry off your hand before attempting a heart rate recording. You could also apply moisturizer to your hand to prevent dryness.  

Please note that because of the clenched position the wrist is flexed in when cycling, the heart rate measurements may have some inaccuracies.

You can position your ScanWatch 2 on the lower part of your wrist. Note that we cannot guarantee the accuracy of the heart rate data, because the product is not aimed to be positioned on the lower part of your wrist.

PPG quality can differ from one wrist to another. We have demonstrated statistically that non-dominant wrists provide better results. However we have observed also on some users that it can be the dominant. Therefore we advise to test both wrists to have the most accurate HR data.

To obtain the most accurate results please follow these guidelines:

• The ScanWatch 2 should be worn tightly enough that the sensor on the back of the watch face touches your skin.
• Wear the watch 1 to 2 finger width away from your wrist bone.
• Use the wristband Withings provides with your watch.
• Make sure that your watch stays in place during exercise. If it moves around at all, tighten your band one notch.
• Make sure your band is secure, but not too tight. It should be comfortable and allow proper circulation.
• Make sure the watch is clean, so the green LEDs are not obstructed by dust or dirt.

Additional factors that can cause the heart rate to be measured inaccurately:

Skin perfusion

Skin perfusion, or how much blood is flowing through the skin, varies among individuals and according to the environment. In certain circumstances, the watch may not be able to provide an accurate heart rate measurement.

Skin and blood properties

The technology used by the watch is based on the light absorbed by your skin and blood. Any permanent or temporary changes to your skin, such as tattoos, sweat, or even hair on the wrist may affect the measurements.

Environment

Environmental factors may affect the ability of the watch to take an accurate measurement. For example, water may obstruct or modify the light dispersion, and cold weather may impact skin perfusion.

Motion

The watch needs to stay securely in place to provide a heart rate measurement. Activities that cause force to the wrist, such as boxing or volleyball, may not allow the watch to provide an accurate heart rate measurement.

Discrepancies between live Heart Rate monitoring and ECG recordings

If you are seeing discrepancies between your active Heart Rate monitoring and your ECG recordings, this is due to the relative accuracy of the two measurement methods. The Heart Rate algorithm utilizes PPG signals to predict the heart rate passively during the day without user intervention and is quite sensitive to hand motion and watch being too loose on the wrist.

This can affect the algorithm's predictive capabilities. On the other hand, the ECG recording is a more robust measurement method to predict the heart rate value and is measured in a more controlled, deliberate way.

If you still encounter issues, reach out to Customer Service by clicking the Contact us button at the bottom of the page.