I haven’t noticed much of a difference to be honest - especially on the days where it was reporting that I was almost a full four degrees cooler than I was (which would warrant a hospital visit if true) I tried repeating the measurements multiple times to see if it really was measuring at that low of a temperature.
Placement definitely sounds like it might be a culprit here - hopefully we can get some more data from others with armpit and/or chest installs.
Hell… now that’s A LOT of a difference! And your data is even more inconsistent than mine… crazy.
So by now I’d say, just from the collected data of two persons (that’s really not much), the xBT is more or less worthless for accurate measuring…? That’s actually quite a surprise for me, especially since you have it installed in the recommended spot.
But it’s also a surprise because it’s not a “new” implant, so lots of people (I guess) already had one before the Flipper-hype hit - did nobody ever do any cross checks with a simple houshold thermometer? Or is there some difference in the data processing between the Flipper and the old Halo reader? I naively thought the chip would just spit out a temperature and the respective reader displays that exact temperature, but I don’t know if that’s actually the case…
Oh, and don’t get me wrong - I’m totally happy that I have the xBT and it’s still a cool thing to use it with the Flipper! I was just hoping for it to be accurate enough to use it for medical reasons, and at least currently I’m not seeing that.
That’s pretty much my conclusion too - I’m gonna try to keep on doing daily measurements through mid-May so I can at least (hopefully) feel confident about the average difference between the xBT and a “normal” thermometer in order to have a solid offset I can use - but who knows.
I haven’t seen any reports as extensive as your OP here before, although I’m sure I could potentially be missing something buried deep in the forums.
That was my assumption as well, but admittedly I am not actually sure. @amal I know you didn’t design the xBT, but do you happen to have any insight regarding variance between readers?
Oh me too for sure, I love being able to quickly boop my armpit with my Flipper and get a very very rough estimate of my temperature. If another temperature chip ever comes out that seems to be more accurate/reliable/consistent, I’ll definitely get one - and probably keep my xBT if only because removing it wouldn’t be super fun. 
Ditto - I really hope I can get my hands on a good sensor heavy implant someday for this reason. I have to measure so many different things each day, it would be a huge quality of life improvement to just do that with my phone and a glassie. Hopefully we’ll have something in the next five years or so.
I might eventually get a xBT and compare its readings with my BeUno, which gives me fairly consistent readings, but I can’t be sure they’re correct of course.
The temperature is directly encoded in the FDXB data
Have you done any comparisons to a regular thermometer?
Thank you!
Nope… I’m already not very disciplined to read my BeUno regularly although it’s very convenient 
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A regular thermometer is a pain in the a$$ (sometimes literally) to use. And the few times I use a regular thermometer, I’m never sure I use it correctly. Under the tongue? In the armpit ? A frontal IR one ? Or in the ear ? …
Guys… doing science to arrive at answers to questions like this requires proper experiment planning… breaking down the problem into easily testable and repeatable chunks. Comparing the readings from an implanted xBT in one area of the body to any other kind of thermometer being used on another leaves too many variables to discern any meaningful conclusions.
What are the primary the questions we are asking here?
Is the xBT at all accurate (close to “real” temperature)?
What is the tolerance of the xBT sensor (how much variance from “real” temperature will it have over time?)
Will an xBT implanted in area X, Y, or Z of the body be able to produce clinically relevant results?
Each of these questions builds on the other, and in reality you need to build independent experiments to answer each one.
First; find a really accurate thermometer with extremely low error margins. This is not necessarily easy… but generally speaking a good basal thermometer should do well because the application require extreme precision over a general purpose thermometer… and with the digital models you often get an extra digit of precision on the read-out. Of course that extra digit might not amount to much depending on the margin of error, but at least it’s there.
Now set up an experiment using warm to hot water.
Let things equalize for about a minute, and take a reading at least 3 times in a row.
This simple setup will let us know if the xBT is even remotely close to the “real” temperature, assuming the basal thermometer is properly calibrated etc. Also by immediately taking 3 to 5 readings, we will also get to see if the margin of error is drastic or subtle.
Depending on the cooling calculator’s output, you will want to take 2 back to back readings at an interval that will get you at least 10 readings spaced out by at least 1 minute between before the water reaches ambient temperature. So, the larger the container, the slower the water will cool. If the calculator tells you it will only take around 6 minutes to go from 40C to “room temp” whatever that is, then you’ll probably want a bigger container.
Of course, taking the readings should require minimal interference with the water in the container. You should try to set things up so you can take a reading from the xBT without having to reach in and grab it. The basal thermometer should be able to be activated without having to remove it from the water as well.
Now that we have some understanding of the xBT’s accuracy and margin of error across the relevant thermostatic range, we can move on to the next test - testing the efficacy of different subdermal locations on the body.
Ooookay… I’m currently on holiday, and I’ve got an xBT lying around here, so maybe I’m gonna try this out (though the chip is all nice and sterile still, and I hesitate on changing that). But I assumed that Destron Fearing built a chip that fulfills at least this
requirement. I mean, it is used for medical reasons - albeit on animals, but considering how expensive especially horses can be, I know there is little margin for errors in that field.
For similar reasons I trust my basal thermometer - women use it to prevent pregnancy, and that’s quite a serious task, so the tools have to work well.
And while I totally agree that there are lots of variables considering chip placement, thermometer used, amount of clothing, surrounding temperature and tons of other things, it’s finally the everyday use that is important. Let’s say the experiment you suggest shows that the sensor itself is fine and is spitting out the same temperature as the thermometer (or something else with a solid offset) - and that’s honestly what I think would happen, I don’t think the sensor is “broken” or unreliable - it is still an existing problem, seemingly, that there is no consistent offset in everyday implantee use.
Main problem is, we have too little data - while @biospoonie and me have relatively similar results, it’s only two people. With 100 people (still a small group) or maybe even 10 one could at least see some pattern - far from scientifically viable, I know, but if we experience wildly variying offsets in everyone, there seems to be something going on 
I still need to get mine installed, bern procrastinating
I think In my usual manner I’ll over complicate things, but have a blast at it
Im going to try to add 2 or 3 other data points into the mix to see if it shows anything
I’ll plan to measure
XBT temperature
Oral temperature
(Maybe forehead skin temperature)
And also try to log ambient room temperature
And make a note of what type of clothes I’m wearing
This is definitely a good thing to do! Since I take my temperature before getting up, I always take care that the bedsheet was covering my body before.
When I took temperature during the day, it definitely made a difference how much I was wearing.
Woohoo - that makes at least three of us who do regular measuring! So I’d say we just have to convince some more people here… like…
I guess I could also just get a basal thermometer and do the test… it would make for good YouTube content maybe
I have a dsruptive temperature chip and a xBt. If you look at the technical specification of the xBt it shows at tests with horses that there is a 3 ° Celsius difference between the xBt and the actual body temperature. If you compare the results with the xBt and the desruptive chip, it verifies this 3 ° celcius difference.
Still, the question here is what do you mean by difference. Do you mean that’s the margin of error? Or do you mean that simply it’s a linear difference at any temperature? It will always be 3° different but extremely accurate with a constant 3° offset? Does the offset change along the temperature scale? Is this a percentage of variance or a strict offset? You know what I mean?
This is why a scientific inquiry requires breaking larger questions down into simple questions you can answer and then build the overall solution from those answers.
The reason I’m suggesting in vitro testing is that the body doesn’t change temperature all that much. I’d like to know what the extremes of the sensors range reveal. Of course then there’s the practical application aspect. Who cares if the xBT is inaccurate at temperatures of 50C or 20C if the body is never going to reach those temperatures. I guess for me, I’m curious what the actual performance of the sensor is regardless of the application. Maybe someone wants to put the xBT into something other than human body to measure temperature.
I know, and it was pretty much what I was expecting - but the problem, as you can see in the data provided by both @biospoonie and me, is that there is no constant offset at all. If there was, it would be totally no problem - either just add 3° to everything you measure, or write a little update for the Flipper or whatever reader you use that does that automatically. But there is nothing like a stable offset at all…
So you have both xBT and BeUno installed - if you read them simultaneously, you say
So, for every reading, there is a stable offset of 3°C between the two implants? This would be really amazing (though to be honest, I am hesitant to believe it)! Where are your implants placed? Have you compared the temperature the two implant spit out to that of a thermometer?
Would be really interesting for sure - measuring temperature is something really useful, the chip itself is very small (so you could put it pretty much everywhere to monitor temperatures), so it would be cool to know how accurate it is and what range of temperature it can take…
This is why it’s important to answer the question of xBT sensor accuracy and margin of error across a wide range of temperatures. Until then, we can’t really know if the implant location in the body is the only reason for such a wide variation of temperatures. But, if we do find out that the xBT has a stable linear offset from control readings, then we can start in on the implant location problem with the confidence of knowing that any variation observed is purely due to location and nothing else.
I think this is a worth while experiment to do … I will start preparing to make a video for YouTube 
Hello, I just received my xbt and can’t wait for the installation. I was wondering does the chip needs to be removed or is it a lifetime long battery ?
There is no battery. It works as any other Chip implant.
I am not a medical doctor but in my opinion, the importance ist not the exact temperature but the deviations between the measurements (eg in a day, in a weeek). For example i noticed, wenn i am sweating, the temperature goes down, wenn i am showering the temperature goes Up. I have the beuno in my left chest and the xBt on my right chest underneath the skin. Of course the core temperature ist more accurate at rectal measurements. But If you dont look at the actual correct temperature, and deviation line you can already figure Out If there is something going on in your body.
