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Correlation between temperature and elevation

Hello guys, can you check on your watches is there correlation between temperature and elevation. When the temperature rises elevation drops and vice versa. So I am from Bulgaria and here is winter now and when I went from warm to cold the watch gain elevation, but when tempering everything works fine. If you see the same pattern give check in my bug report for the beta program if you are on the program.

forums.garmin.com/.../gaining-elevation-in-activity

If you are not can still make good discussions because it's quite annoying...

  • As already mentioned in different posts all those parameters are correlating..

    Please also take into account that the altimeter changes its height with the ambient pressure, so it never will provide a straight line but change a view meters within hours.

    Thats simply physical limitations in determine the altitude this way. So your observations are looking "normal" to me. The idea is here to calibrate the absolute altitude frequently with the GNSS altitude oder the DMM and to calculate the changings in altitude via the pressure sensor via the barometric formula:

    Barometric formula - Wikipedia

    So you should not have to much expectations in the value. It will recognize when you are doing a run or a hike 50, 100 oder 2000 altitude meters but you might always have some final offset of several meters.

    So my question would be - what exactly do you find annoying in the behaviour?

  • I find it annoying because last winter I didn't had those issues. When I go outside and for half an hour the readings are false because when it's cold it gain elevation. My first 2km are flat and I gain 20m of d+. When it tempered everything is ok. So I have to let the watch outside for 10 min to show correct values when I start an activity which I think is not normal for this high end  equipment. Have friend with the same watch and no fluctuations, hope it's sw problem and will be resolved.

  • I agree with you. I almost always run with other people who don't have this problem. Some have the same one as my fr955 

  • I also do not see a difference of 20m wenn doing an activity going outside in the cold. Yesterday for example I did about 8,5 km round course running. Came out from roomtemperature of about 22°C to -5°C. At the end of the course I had a delta of 3m within a bit less then 40min.

    118m up

    121m down

    Thats "normal" for me to define normal.

    So the effect you describe is pretty strange, while the behavoiur you mention in the bug section seems quite normal to me.

    Concerning a possible firmware bug - only garmin knows what they are processing. But if others like your friend or me do not encounter the issue it is either some kind of "setting" leading to that or in the very end a hardware issue.

    Regards,

    Stefan

  • I will wait to see the final update.

  • Out of curiosity - do you wear the watch on your skin or over your cloth?

  • It's a big issue.

    20km on a 2.2km circuit. Starting just outside home, so the watch was about 25°, outside was 4°

  • One more thing. I always do a separate activity for warmup.

    Set altimeter before start with DEM (find correctly 216m for my location), do 10min warmup run, stop activity, wait 1min before starting a new activity for training session. Then start a new run session and before calibration with DEM it says "235m", in a place with similar elevation of my home! It misses the altitude of 20m in the space of just 10 minutes due to the watch cooling down!!

  • On skin, today I try to leave it outside for 20 min but it was -11 and the gps went wild for the first 2kmGrinJoy

  • I'm wondering because I never noticed this kind of issues. I also often had this warm-cold transistions because I use the watch for cross country sking. If it gets at some point cold again here I will be aware if it happens at some point and if there is a way to reproduce is.

    I also rechecked my cross contry activities and is have deltas between 1 to 10 vertical meters on back on the starting / return point with total vertical meters of about 350m.

    But this seems normal to me taking into account that ambient pressure can easily change 1hPa within one hour, resulting into a elevation difference of about 10 meters.

    So in my opinion it should be possible to export the raw readings of the barometer so you can check the readings before the calculation and algorithm magic starts. So you could check better if the barometer works properly and if this is ok, the issue is probably software related. Because regarding the graph miky posted it could just be, that the ambient pressure dropped during his workout.