What is your experience with wrist temperature sensor?

[kubaw]

My wife is using wrist temperature sensor for 10 days now and it seems very unreliable. The baseline deviation graph fluctuates a lot (although we are sure there should be no such fluctuation):

Also if I look at the raw data, the "surface temperature" to "wrist temperature" deduction algorithm seems total magic since i.e. one day for surface 36.06 it has shown wrist as 36.58 while the other day for 35.69 it has shown 37.07.

My wife is sleeping more or less the same number of hours, in the same room, with watch charged and on the same wrist, same position. What could be the reason for these fluctuations? What are we doing wrong?

 

[betasp]

Get an actual thermometer and take her temperature at the same time and intervals each day. Make sure it’s accurate to .1 degree and look at the fluctuations that happen to the body.

Saying there should be no fluctuations tells me you haven’t done any research at all into what it normal for a human.

 

[kubaw]

Get an actual thermometer and take her temperature at the same time and intervals each day. Make sure it’s accurate to .1 degree and look at the fluctuations that happen to the body.

Saying there should be no fluctuations tells me you haven’t done any research at all into what it normal for a human.

This is exactly what we do for years. That why I know there should be no such fluctuations. I hope your day is better after this useless, passive-aggresive, and most of all: simply wrong comment about my personal research experience.

 

[papbot]

This is exactly what we do for years. That why I know there should be no such fluctuations. I hope your day is better after this useless, passive-aggresive comment about my personal research experience.

The image you posted seems to show normal fluctuation around a normal baseline. Which is what I would expect. These days a lot of us check our temps regularly and using the most accurate thermometer I have, an oral mercury thermometer that I’ve had for ages rarely shows the exact same temp on multiple checks. I can sit on my couch and check every 15 minutes or so for a period of time and they are almost always slightly different. If you use the modern infrared digital scanners they will vary even more. So I’m not sure there’s any issue here.

 

[kubaw]

The image you posted seems to show normal fluctuation around a normal baseline. Which is what I would expect. These days a lot of us check our temps regularly and using the most accurate thermometer I have, an oral mercury thermometer that I’ve had for ages rarely shows the exact same temp on multiple checks. I can sit on my couch and check every 15 minutes or so for a period of time and they are almost always slightly different. If you use the modern infrared digital scanners they will vary even more. So I’m not sure there’s any issue here.

Thanks. The rules of fertility planning expect measurements to be taken with the same thermometer, the same method, at the same time of morning (just after wakeup) to minimise fluctuations. Of course we observe some variation, but this stays in range of +/- 0.15 C. Fluctuations as shown by AW8 (that is about 0.7C delta) make this data useless for fertility planning, as +0.4C is a typical temperature raise for post-ovulation period. And this contradicts the whole point of fertility planning feature of the new watch.

For comparison a plot of temperature taken with classical approach, please compare the fluctuations (low measurement around 1st of June is measurement error):

That's why I wonder what are others' experiences with Apple Watch accuracy. Maybe we have a defective unit, but more probably we just do something wrong, and I want to find out what.

 

[anodibu]

Mine seems to fluctuate less but I’m male if that matters. Keep in mind that the number shown is an average of the entire night. It would be interesting in also seeing the individual measurements and how they fluctuate within the night. Apple says fluctuations up to 1°C are normal.

 

[kubaw]

Mine seems to fluctuate less but I’m male if that matters. Keep in mind that the number shown is an average of the entire night. It would be interesting in also seeing the individual measurements and how they fluctuate within the night. Apple says fluctuations up to 1°C are normal.

Thanks, yours look like something one could rely on with fertility plannig, as the fluctuations are within expected range, so the raise of the temperature is detectable. This again makes me concern, that we are doing something wrong. Maybe she is sleeping on her hand for some part of the night? Don't know. :/

Would you mind showing raw data for both surface and wrist temperature? I know i takes some time to dig.

 

[anodibu]

Thanks, yours look like something one could rely on with fertility plannig, as the fluctuations are within expected range, so the raise of the temperature is detectable. This again makes me concern, that we are doing something wrong. Maybe she is sleeping on her hand for some part of the night? Don't know. :/

Would you mind showing raw data for both surface and wrist temperature? I know i takes some time to dig.

Sure, here are the last 5 readings of surface and wrist:
35.54 / 36.13
35.76 / 36.19
35.56 / 36.26
35.45 / 36.06
35.68 / 36.25

 

[drew0020]

Personally I think it’s half baked - it’s not even fair to call it a temperature sensor. I wanted a sensor on demand not having to wear it at night for a week lol.

It’s similar to the Blood Oxygen monitor (works 50% of the time maybe), but Apple needed something to call it the S8.

 

[chanerz]

I turned mine off. I wanted to be on demand not like wait for a week .

 

[kubaw]

Sure, here are the last 5 readings of surface and wrist:
35.54 / 36.13
35.76 / 36.19
35.56 / 36.26
35.45 / 36.06
35.68 / 36.25

Thanks, this is valuable input as it shows that it is normal (and as I expected actually) that lower surface may result in higher wrist and the other way round.

 

[FunkyTang]

Seems incomplete that they don’t graph the actual temperature readings, just the differentials from baseline.

 

[Gix1k]

How do you use this sensor? I didn’t see in settings.