The heart rate sensor measures your heart rate in Beats per Minute using an optical LED light source and an LED light sensor. The light shines through your skin, and the sensor measures the amount of light that reflects back. The light reflections will vary as blood pulses under your skin past the light. The variations in the light reflections are interpreted as heartbeats.
Measure heart rate on Samsung phones
There is a difference in the light intensity when there is a pulse. The heartbeat is measured by counting the changes in light intensity between the minute pulsations of the blood vessels. Many fitness and health apps use this method to calculate the heart rate.
Heart rate sensor measures your heart rate with a light and sensor located on the back of supported devices.