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crwdns2892146:0Jeff Suovanencrwdnd2892146:0crwdne2892146:0

crwdns2875918:0crwdne2875918:0 crwdns2892120:0crwdne2892120:0 Jeff Suovanen

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-[* black] Last call: back glass. The rear panel material has been standardized across watch models and souped up to snazzy ceramic, replacing the previous Ion-X or Sapphire options.
-[* black] The back glass contains the [https://en.wikipedia.org/wiki/Photoplethysmogram|PPG sensor array|new_window=true] that is responsible for sensing heart rate.
- [* black] It would've been cool to see some change from [guide|67385|the Series 2|stepid=136503|new_window=true] after [http://appleinsider.com/articles/15/10/23/apple-watch-users-complain-of-inaccurate-heart-rate-readings|complaints about accuracy|new_window=true] in previous models. As far as wearable's go, however, the Apple Watch [http://appleinsider.com/articles/17/05/24/stanford-study-finds-apple-watch-top-notch-heart-rate-monitor-mediocre-calorie-counter|is the best of the bad|new_window=true].
+[* black] Last call: back cover. It's press-fit over a teflon-like O-ring, but a thumbs-up and a firm push relieves it of duty.
+[* black] The material has been standardized across watch models and souped up to snazzy ceramic, replacing the previous Ion-X or Sapphire options.
+[* black] It also houses the [https://en.wikipedia.org/wiki/Photoplethysmogram|PPG sensor array|new_window=true] that is responsible for sensing heart rate.
+ [* black] It would've been cool to see some change from [guide|67385|the Series 2|stepid=136503|new_window=true] after [http://appleinsider.com/articles/15/10/23/apple-watch-users-complain-of-inaccurate-heart-rate-readings|complaints about accuracy|new_window=true] in previous models. As far as wearables go, however, the Apple Watch [http://appleinsider.com/articles/17/05/24/stanford-study-finds-apple-watch-top-notch-heart-rate-monitor-mediocre-calorie-counter|is the best of the bad|new_window=true].
[* black] Also it appears that the wireless charging coil has been slightly modified to support ''[https://www.theverge.com/circuitbreaker/2017/9/22/16349480/apple-watch-series-3-qi-wireless-charging|most|new_window=true]'' Qi wireless chargers.
-[* black] barometer hole thing
+[* black] Lastly, we find a significant-looking hole in the case near the diagnostic port. Perhaps this is a diaphragm allowing the internal case pressure to change in support of Apple's touted "new " barometric pressure sensor? (We're a little confused, because [guide|67385|we already found a barometer in last year's model|stepid=136502|new_window=true].)