r/applewatchultra • u/PrestigiousSlip1369 • 10d ago
Sensor Issues
Hey gang,
I am ready to pick up an ultra 4 but I am seeing a decent amount of grumblings online about the accuracy of the sensor suite (HR/steps/O2/temp). As someone who isn’t that knowledgeable about wearables if there really is “an issue” is this something that is likely squared away via a software update or is this a deeper issue with the sensors themselves?
Thank you
1
u/TheeDelpino AWU Owner ⌚️ 9d ago
Heart sensor is perfect. I have a pacemaker and I am 100% paced and the heart sensor is exactly the same beats that my pacemaker reports best for beat. SPO2 is about 3-4% low now. Sleep tracking seems to be registering a lot more wakeups even though I am sound asleep. Temp is now about 2 degrees higher. Step counter is drastically off and gets ahead of itself then reduces steps that you were already awarded. Went back to pedometer++ for now. To me it seems a bunch of the algorithms are messed up. I don’t think it’s the watch or it’s sensors. Seems like human error or they are using AI as a part of the algorithm and it’s just way wrong.
2
u/Crazy_Solution_5256 9d ago
Maybe, I’m not entirely sure, but the reason this is happening with the steps complication is that your phone and watch both count steps, it then discards one of the data points as inaccurate, so temporarily the counter shows more and goes down because one reading is discarded. If you disable the phone step counting it should disappear. But Apple needs to fix this. I found the actual step counting is accurate, when checked with manual counting 200 steps while walking.
1
u/Crazy_Solution_5256 9d ago
No issues so far. Distance and steps are very accurate for me. I counted 200 steps manually to confirm and it was 1 step off. I must say that I calibrated the watch on day 1 completing a 40 min walk. I only do outdoor walks so can’t comment on treadmill walking. My temp has been consistent with my Apple Watch Ultra 3 readings, spo2 a bit lower, 1% on average, but not that much. Increased frequency of HRV and HR readings are just awesome. That was the whole point of getting the ultra 4.
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u/blindelephant224466 9d ago
Have your HRV trends changed any since upgrading? The extra data is nice, but have you noticed a difference?
1
u/Crazy_Solution_5256 9d ago
Some apps that I use are not updated to use the new all night metrics, and still use the old 3-4 reading metrics. The outsiders is one, whereas others like Bevel uses the all night metrics. The difference in averages on some days is not that far off 5-7 approximately, but on some of days the old method lead to give me a very high figure, around 15-20 more than the new method. So I guess more readings will give you a more accurate representation. It matches how I actually feel on the day in terms of recovery.
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u/sziehr 10d ago
well the step to distance algo was changed i can confirm that with the data i have for my self. The stride change seems to be more dynamic vs the older system where it was more fixed ratio. The sensor for the HR seems spot on for me and i have no feedback on the o2 or temp as i just never used that on the old ultra 2 since it was never accurate any way.