Apple picked a good heart rate sensor for the Apple Watch.
After a series of tests by Mac and iOS developer Brad Larson in which raw data was extracted from both devices, the heart rate sensor on the Apple Watch was determined to be nearly on par with the Mio Alpha, a popular dedicated heart rate sensor also worn on the wrist. The Alpha produced sharper peaks, which may suggest more filtering on the Watch, but in most cases the data produced was essentially equal.
The two wearables each use optical sensors that measure reflected light to gauge blood flow. Larson noted that the sensor on the Watch takes a reading every 5 seconds while in workout mode, slowing to once every 10 minutes while in regular use.
Apple recently encountered some controversy with the sensor when it confirmed that the Watch may not work properly for people with wrist tattoos, a consequence of using optical technology. The company changed a support page to state that the “ink, pattern, and saturation” of some tattoos can make it “difficult to get reliable readings.”
Some users have worked around this issue by disabling wrist detection, which relies on the heart rate sensor. Turning the feature off also disables Apple Pay, and tattooed people may have to buy a separate tracker to get an accurate heart rate.
Stay tuned for additional details as they become available.
Via AppleInsider and Brad Larson