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Altimeter Fenix 5

This morning, as I always do, I drove 22 miles to work in the North west of England. According to several websites there is a difference in altitude between my start and finish points of circa 220 feet, the altimeter on my Fenix 5 shows no difference in altitude at any time in the last 4 hours. Is there a setting that I have wrong or is it a faulty unit?

I've had the watch less than a week so haven't noticed this before, so I don't know if this is the first occasion or whether or not the unit has been showing different altitudes previously.

Any assistance would be really appreciated.
  • It's the same here. No watch face, 7.6 firmware and didn't connect my phone since 5 days and everything seems to be OK...
  • Former Member
    0 Former Member over 7 years ago
    Problem free for a week. Haven't changed firmware or watch faces. Even put the watch back into auto calibration and auto watchmode. I was at a lower elevation for a few days (though I doubt that would make such a difference). Wondering if they fixed something on the back end.

    Sidenote: I called customer support again after the last instance and was told this is a "small" issue relative to total units. They speculated that it was a sensor/software interaction problem, but couldn't say for sure. So they started the RMA process, but couldn't promise the issue wouldn't be present on the new watch.
  • This afternoon my Barometer, Altimeter and Thermometer are non-existent - literally - just tried restarting the watch and they read ----.-, blank and ---

    Must be a software glitch or sensor glitch that causes the software to ignore them completely.

    Wait - just now my barometer just came back to life and is reading -0.3 mBar and altimeter is reading 65617 feet and temperature is reading 54 degrees F.
    Barometer is now at 133.2 mBar and temperature is 55 degrees ....
    Altimeter is now at 48548 feet and rapidly dropping
    Temperature is now 57 degrees
    Altimeter is now at 41400 feet ....
    Temperature is now at 58 degrees
    Altimeter is at 36224 feet
    Barometer is at 596.3 mBar

    I have an Ambient pressure widget that is rising fairly rapidly (correct pressure is around 1000 MB.) It started near 0 and is in the 400 MB range now and climbing.

    Looks like things are converging in the correct direction ....

    There is a relationship between Altimeter and Barometer that has been discussed a lot here. There is also a relationship to the temperature sensor.

    If there is a glitch in the way the sensor is read, it would throw all of this way off - might be a timing thing or protocol corruption thing.

    BTW - I am running stock watch face but do have several other Connect IQ ones loaded in memory (not active though).


    OK I'll stop the real time updates ....

    (actual 619 feet above sea level ...)

    Watching this behavior makes me think the sensor is fine but the algorithm that reads it has some hysteresis and when it gets a glitch it changes drastically but then takes time to recover.

    This is the only issue I have had with my Fenix 5 (non Sapphire) - It is an early production one and works great otherwise (GPS spot on, great battery life).

    I have been using it for floor climbing the last 2 weeks and it has been fairly accurate with that ....
  • Former Member
    0 Former Member over 7 years ago
    Sidenote: I called customer support again after the last instance and was told this is a "small" issue relative to total units. They speculated that it was a sensor/software interaction problem, but couldn't say for sure. So they started the RMA process, but couldn't promise the issue wouldn't be present on the new watch.


    In other words, they don't really know what the problem is, and therefore don't know if any other units are affected by it. So if you exchange for a new one, it's pretty much just a gamble if it has the same problem.

    I'm on my second watch with the same problem. Gonna return it for a third and cross my fingers I guess. But who's to say it doesn't work for a few months and then start going haywire like some others have on this thread? At least my first couple started to go bad after a few days. It's gonna be hard to trust that this watch will remain functioning in the long run.
  • Former Member
    0 Former Member over 7 years ago
    I am just joining this thread. I've had a Fenix5x for about 8 months. I also find the altimeter to be erratic and needing frequent resetting. One observation- I think plane flights mess it up. I recently flew from Boston to Wyoming and by the time I arrived at Yellowstone, the altimeter was nearly 1000 feet off. Likewise back near Boston today, again nearly 1000 feet off.
  • I also find the altimeter to be erratic and needing frequent resetting


    That is how a barometric altimeter is supposed to work. Your calibration/resetting is only valid at the exact time and location where you do it. If you wait, the ambient pressure at your location will change, and the calibration is not valid anymore. If you move to another location, the ambient pressure at the new location will be different - even if they are at the same altitude - and the calibration is not valid anymore.

    In your example, you moved 3000 km and expected the old calibration of the altimeter to still be valid. That will never happen, unless you find a planet with constant pressure at sea level all over the planet. It is not this planet.

    On this planet, it works like you can see in this link:
    http://www.dmi.dk/vejr/til-lands/vejrkort/

    Select the "Frontkort" tab and then look at the image with the label "Tirsdag den 30. januar kl. 13.00". This image will unfortunately only be there for the next 24 hours, and then it will be replaced with newer images. I tried to attach it as a photo to this post, but Garmin won't let me.

    This is a map of expected air pressures tomorrow (normalized to sea level altitude) all over Europe. At the big blue H you have a high pressure of 1030-1035 millibar. At the big red L you have a low pressure of 985-990 millibar. So the pressure difference between these two locations will be 40-50 millibar.

    Imagine that you stay at the big blue H and calibrate your altimeter. Then you quickly move to the big red L (by plane, supercar, really fast train, doesnt't really matter) and find a spot there at the exactly same altitude as where you left. The ambient pressure sensor in your watch measures 40-50 millibar lower than it did when you last calibrated the altimeter. So the altimeter will think that you have moved to a higher altitude. Each millibar is approx. equal to 27-30 feet of altitude, so those 40-50 millibar will translate into 1000-1500 feet altitude increase.

    So that is what the altimeter will tell you: You have moved to a 1000-1500 higher altitude. Even though you are at the same altitude as you were when you last calibrated the altimeter.

    In the example above, there is approx. 1500 km between the L and the H. In your example, you traveled twice as far.

    TL;DR version:
    Calibrate your barometric altimeter whenever you need it, or stop using it.
  • Yesterday had a glitch (first in several months) the altitude went up to 3000m and the slowly went down to normal value, didn't reset altitude. For the record: I was with a non stock watch face, the outside temperature was 19ºC and dewpoint 10ºC and I was using a cotton cloth. So, the only common factor with previous situations was a non stock watch face.
  • Former Member
    0 Former Member over 7 years ago
    Just updating the thread, figure any information I provide can help.

    I got my third F5 two days ago. Set it up, updated to 7.6 firmware. No new watch faces. Android version 6.0.1.

    Set up one of my activities to display ambient pressure on a data field as I always do.

    On the very first day of having the watch, the altitude fluctuated to 60,000+ft, ambient pressure dropped to "--.--" or in other words, zero/not detectable It stayed like that mostly all day and slowly recovered over night and through the next day while not wearing the watch.

    Once I put the watch on again (wearing my long sleeved polyester fleece), ambient pressure again starts to drop to 100mbar or so and gradually climb back.

    It can't possibly be solely hardware failure in three consecutive watches. Am I crazy to assume that?

    I know it has been suggested previously that the sensor is susceptible to electrostatic charge from clothing, but I feel like if that were the case, there would be way more people noticing altitude/pressure sensor errors.

    In my previous two watches I would do the warm/soapy water bath which helped but the problem would always come back.

    I haven't even used this one for anything other than around the house.

    Should I have to turn off my bluetooth on my phone, not wear anything long sleeved, soak my watch in a bath daily in order to just get it to work properly? I think that's asking a bit much for an expensive watch like this...

    I'm gonna try to experiment with and isolate different factors to see if they affect how the pressure sensor works over the next few days to see if any one thing contributes more to improving the functioning of the sensor. Seriously thinking of switching back to the brand that rhymes with "uunto" if this watch continues to carry on like this.

  • It can't possibly be solely hardware failure in three consecutive watches. Am I crazy to assume that?

    [...]

    In my previous two watches I would do the warm/soapy water bath which helped but the problem would always come back.


    It seems clear to me that if the soap bath treatment helps, then it can't be solely software error either, since soap baths can't cure software problems. (Of course unless the pressure increase in the bath will trigger something in the software.)
  • Former Member
    0 Former Member over 7 years ago
    After upgrade to version 7.60, my Fenix 5 started to calculate the climbed floors strangely. Its started to count floors in elevator, which is never happens before. It's also requires altimeter calibration once in few days.
    Anyone else with such problem?