Why does the Redmi Watch 5 fail to measure heart rate?

Several factors will make the Redmi Watch 5 fail to measure heart rate, such as heart rate monitoring settings, inaccurate wearing position and dirty back cover lens.
If the Redmi Watch 5 fails to measure heart rate, please refer to the following details:
1. Disable all-day heart rate monitoring, tap the Heart rate APP on the watch, measure the heart rate once, and when the watch is measuring, check whether the heart rate light on the bottom of the watch is on;
2. If it is not on, you can unbind and rebind or restart the watch and clean the back cover lens (dirt and oil will affect the test and accuracy);
3. If it is still ineffective, you can apply for after-sales inspection.