Comparison between xBT and thermometer

Thank you for doing this @Coma! I really appreciate the thorough write up and attention to detail. I plan on getting an xBT under my left armpit in January, and will do the same kind of comparison.


That’s what I hoped for - there was such a big interest about the xBT here, so I hope we can gather some information, especially regarding the various possible placements and all :slight_smile:


@darthdomo you did a armpit install recently, any chance you wanna measure a bit to see consistency?


The more data the better!

My first look at your graph, and I’m like…


It’ll be interesting to see how others compare. Especially the armpit vs armpit implant

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I think the ancient one formerly known by R did an armpit install…
Idk if they posted a proper spreadsheet of data points, but I feel like they did… but its hard to find now because their username is an ANON

here is what I could scrounge up, I feel like there was better concrete data somewhere… but this is what happens when you delete your account * shrug*

I’ll try my best to do it later this week, don’t have any class after tomorrow.

So far, my experience has been pretty bad with consistency, but I’ll track it (assuming I have my thermometer here…)

If not, I’ll do it in 2 weeks or so when I head home.

no pressure… thanks

depending on your data, or a flip of a coin… wherever I decide to get mine implanted, Ill try to record some data points

I got an xBT in the arm pit. Ill also try to record. The only thing is my was installed less than a week ago so it gets inconsistent reads due to swelling right now.


Yeah, I just didn’t really bother to translate the title, and the units are all metric, and the date format is the one used in Europe - I’m pretty sure the formatting alone might get some people nervous here :smile:

But I’m a bit confused about it myself. It’s not like my temperature cycles are super-consistent (tbh, they’re totally not), but I was kinda expecting a more or less stable offset. At least that’s what a similar graph on one of the veterinary supplier’s page shows - two lines, one from the chip and one from rectal measuring, both lines looking exactly the same (just about some degrees in between, of course). I know rectal measuring is more exact, that’s why I do this 3-minute-thing with my oral thermometer. But this all varies wildly…

Maybe there is more consistency in animals because of thicker skin, fur and all that stuff (anyone got a sphynx cat? For science… :smile: ). Or I’m just being stupid and missing something obvious :woman_shrugging:

I’ll keep tracking it anyways, let’s just see how it develops. And I’m happy if others join in, of course - I’ve got another xBT here, ready for install, so if there’s a different placement that looks more promising, I’ll happily try it out :wink:



That joke seems in poor taste



Okay, so I’m still comparing the different measurings, and it still looks not really like a solid, even offset at all. The lines are roughly going the same direction, most of the time, but the difference varies quite a bit.

So I had another idea - is there someone around here who owns both a flipper and one of the older Halo readers? I’m really curious if there is any difference if you scan the xBT with those two. Obviously, there shouldn’t be any, but I’m curious :wink:


Agreed, hope someone does. I’ve thought about getting a Halo reader for the same reason.

The code that the Flipper uses comes from the Iceman repo, and was originally written by Rosco trying to reverse engineer the protocol.

I’m sure he would have done all of the testing he could have, given he had a Halo, but I’ve been curious if there was a rounding issue at some point or something.

It really does seem super inconsistent in my testing.

Roscos thread as linked by Eriequiet above has a good amount of information where he used the Halo, im not sure if there is anything mentioned in there that will help clarify
lo led again below for convenience

He also exploited the sure sense reader and i’m pretty sure he did a temp comparison between the Halo and Suresense

There might be something in there but :man_shrugging:

You did a chest install right?

I’d like to see someone with an armpit install post some data, I wonder if the chest just had a bit more variance?

I’ll work on tracking mine next week once I’m home in Indy, but it’s not looking great with mine…

Still having massive variance, even just 15 minutes apart

Yep, I did, and a relatively deep one (like, not in the muscle, but I can’t feel the chip when poking around).
I’m really curious if an armpit install is more reliable, I’d like to see some data there as well :wink:
My thought was that the armpit should vary more, because it makes quite a difference if you extend your arm or keep it to your side - at least I guess so :woman_shrugging: And the chest is closer to the core, so not much affected by the body’s mechanism of reducing blood flow to the extremities when getting cold.

That’s so strange! I mean, I have no clue about how the chip actually works, but I was naively thinking it just takes the temp around itself and spits it out - that shouldn’t lead to much variance, I guess, as long as you don’t “create” variance around it, like hot bath tub vs. running around naked in winter.
But I have even less clue about how the readers work, and if it’s possibly a problem on that side… gonna try to do some research about that.


Thanks, took a look at it, and that reader seems a little off compared to the halo as well - so there seems to be variance depending on what reader you use…

Got some preliminary data from comparing the xBT (+Flipper) and the Thermo from Withings. I’ll still be measuring post-healing period for three months or so, but even with the data integrity challenges that come with collection during healing, I was still interested. Especially as this install (about ~1CM below where the hair stops in my left armpit) seemed to heal very quickly. I am a bit of a chunky guy, but I can’t feel the xBT at all when I try and “look” for it in the spot it was installed.

I didn’t record basal temperature as I can’t remember to do shit when I wake up in the first place, so that didn’t work quite so well for me. Temperature was taken at random times each day, sometimes close to waking up, sometimes not.

Here is a graph comparing the temperatures from each device:

Here is a graph calculating the daily difference and average difference between the devices:


As you can see, there is a ton of variance - some days they’d be within 1/10th of a degree, other days it was a whopping ~3 degree difference. I was expecting variance due to healing, but not for the xBT to be lower (especially by such a large margin) than the Thermo. I’m gonna keep measuring for the next few months and report back - hopefully the variance decreases a bit. Either way, at least I’ll be able to have an average difference that I can use to calculate my “actual” temperature whenever I do an xBT reading.

Edit: Oh yeah, here is the Google Sheet I’m using to calculate things + collect data if anyone is interested.


Which is more Accurate? XBT or thermometer?