Revealing how the Apple Watch heart rate monitor works

There is still a lot we need to know about Apple Watch, and Apple knows this. Recently, they have updated the support page on their official website to let users learn more about how the heart rate monitor in Apple Watch works.

Apple says the heart rate monitor used on the Apple Watch is called "photoplethysmography", but it's actually based on a very simple technology, so you don't need to understand this complicated term.

Blood is red because it reflects red light and absorbs green light. Apple Watch uses green LED lights and photodiodes to monitor the amount of blood flowing through your wrist at any important moment. As your heart beats and blood flows through your wrist, the green light absorbs. Between each heartbeat, there is less blood flow. By flashing the LED light hundreds of times per second, Apple Watch can calculate the number of heartbeats per minute - your heart rate.

In addition to green LED lights, Apple can also use infrared light to track the wearer's heart rate. In fact, infrared light is the main means used by Apple Watch to measure the wearer's heart rate, which is measured every 10 minutes. Only when the infrared system is unable to obtain appropriate readings will the system switch to green LED light for monitoring.

In addition to explaining the technology, Apple also provides potential customers with advice on how to obtain better monitoring data. First of all, the watch must fit your wrist and not be too loose. In addition, heart rate monitor readings also depend on the external temperature and the exercise activity the wearer is performing.

Most Android Wear smart watches on the market have difficulty working properly during exercise, so it is worth looking forward to whether the heart rate monitor on the Apple Watch is powerful.