Heart rate accuracy

Regarding heart rate monitor, it may be caused by the following:

1) Not wear it properly

Inaccurate heart rate readings appears to be due to the fit of the device band itself. A loosely fitting band that moves around at all, or that has notable gaps between the device and the skin, can easily cause an inaccurate reading. For the most accurate heart rate readings, you will want to be sure you’re wearing the device on the top of your wrist and it's fairly snug against your skin.

2) irregular movements

Rhythmic movements, such as running or cycling, give better results compared to irregular movements, like tennis or boxing. We advises tightening your watch band for workouts to reduce any chance of false readings, then loosening it when you’re done.

3)Skin perfusion/environment affect performance

As the heart rate sensor is basically a pulse oximeter which monitors the perfusion of blood to the dermis, it’s prone to inaccuracies.That’s because skin perfusion — a measure of how much blood flows through your skin — varies significantly from person to another.

Especially the ones who have dark skin, hairy wrists, tattoo, and scar.

4)Light sensors on the back of the device are obstructed

If you’re seeing a reading that doesn’t look quite right, please check the following:

1)Take a second measure if you thought the reading isn't right. 

2) Keep it close to your skin

3) Clean the heart rate sensor

Soak a cotton swab with rubbing alcohol and clean the surface of the sensor on the back of the device.

Make sure that no debris from the swab is left behind.

Wipe with a dry cloth or tissue.

Hope this info helps.   If the cardio displays very high values during the activities with the latest ROM, please replicate the issue with a new activity with the following steps:

1. Swipe down from the watch home screen, you can see four icons System Settings: Airplane, Silent Mode, Backlight, and Settings. 

2. And then tap the fourth icon Settings.

3 Swipe UP until you find Huami Lab and Feedback

4. Tap Huami Lab and you will see Activity data collection

5. Click to turn on Activity data collection

6. Choose a sports mode to start your activity

7. After you finish the workout, please turn off Activity data collection 

8. Tap Feedback to generate reports.

9. Please tap Profile/Me at the bottom right of app and send us the Amazfit ID which is right below the user icon.

10. Submit a feedback(APP--Profile--Feedback--User ID) from your Amazfit watch app

11. Please send us some screenshots of the activity including Details, Routes and Graphs.