How the Apple Watch heart rate sensor works, according to Apple<article>
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If you’re curious how the Apple Watch’s heart rate monitor works, the company is now happy to explain.</p><p>
A new support document on Apple’s website describes exactly how the watch measures your pulse, how often the readings happen, and what factors might affect the readings for better or worse.</p><p>
Similar to many other wearable fitness trackers, the
Apple Watch relies on green LED lights for a method called photoplethysmography (or PPG). Because blood absorbs green light, and each pulse brings a spike in blood flow, determining heart rate is a matter of measuring the changes in green light absorption. During workouts, the Apple Watch does this by flashing green light onto your wrist hundreds of times per second, then measuring light absorption with photodiodes.</p><p class="jumpTag"><a href="/article/2911939/how-the-apple-watch-heart-rate-sensor-works-according-to-apple.html#jump">To read this article in full or to leave a comment, please click here[/url]</p></section></article>
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How the Apple Watch heart rate sensor works, according to Apple
