My Apple Watch heart rate monitor occasionally reads as low was 30. When this happens and I manually check my pulse there is a large difference, i.e. my pulse is 70.
My question is, is this a defect in my watch or is that the way it is?
watchOS 2.2.1
Hi
Consumer Resports tested the heart rate sensor against their highest-rated dedicated heart rate monitor and found "no significant differences" between their readings:
http://www.technobuffalo.com/2015/04/27/apple-watch-performs-well-in-consumer-re ports-tests/
However, Apple advises that, even under ideal conditions, Apple Watch may not be able to record a reliable heart rate reading every time for everybody.
For the best performance from the heart rate sensor, check that you are wearing your watch sufficiently snugly on the top of your wrist. The fit should be neither too tight nor too loose, allowing room for your skin to breathe:
For the best performance during workouts, Apple suggests that you consider tightening your watch band beforehand and loosening it again afterwards.
The sensor is likely to give better results for workouts that involve rhythmic (eg running) rather than irregular (eg boxing) movements. During any workouts that involve flexing your wrists (such as weight training, for example), it may help to move your watch a little higher up your arm, away from the flexing joint.
Other issues that can impact sensor performance include skin perfusion and wrist tattoos - see the link below for more details.
Apple advises that, if you experience inconsistent readings, you consider connecting your watch wirelessly to an external heart rate monitor (eg a Bluetooth chest strap) during workouts:
Your heart rate. What it means, and where on Apple Watch you’ll find it. - Apple Support
If you remain concerned about a potential manufacturing defect, I suggest that you contact Apple Support (mail-in service may be available) or make a Genius Bar reservation with a view to having your watch checked (under warranty, if eligible):
To check your warranty status (the serial number is on the back of your watch):
How Accurate is the Watch Heart Rate Moniter?
