Apple Watch Support Articles

[Hicks.]

I hadn't noticed this before "Wearing Apple Watch" https://support.apple.com/en-us/HT204665

I hope Apple doesn't get a Fitbit problem at some point, with people who are allergic to wearing straps, bands – materials in general.

And there is also one on the heart rate sensor, which measures your heart rate every 10 minutes and the article uses a great word: "photoplethysmography."

"The heart rate sensor can also use infrared light. This mode is what Apple Watch uses when it measures your heart rate every 10 minutes. However, if the infrared system isn’t providing an adequate reading, Apple Watch switches to the green LEDs. In addition, the heart rate sensor is designed to compensate for low signal levels by increasing both LED brightness and sampling rate."

And interestingly...

"If you’re not able to get a consistent reading because of any of these factors, you can connect your Apple Watch wirelessly to external heart rate monitors such as Bluetooth chest straps."

https://support.apple.com/en-us/HT204666

 

[Stupotpot]

It also raises an interesting point that the sensors only work when worn on top of the wrist!

 

[Hicks.]

I think that is the norm for wrist-based sensors. Fitbit has the following advice about their Surge/ HR products:

As shown in the Surge illustration below, for all-day wear when you are not exercising, your tracker should usually rest a finger’s width below your wrist bone and lay flat (as you would usually wear a watch). Do not wear your tracker with the display on the inside of your wrist.