Instinct 2x Solar Altimeter problem

It just did it again. Was manually set to 125 ft now it shows 165 ft and I didnt move anywhere other than to the other room in my home. Is this a defect in the watch? 

well, if you take watch off your wrist for some time - is altitude changing? if you can see correlation between altitude/pressure and the temperature changes (on watch there is glance for it), then go support. that's what i had to do and got replacement 

Is your altimeter drifting over night? 

Starter this thread (with a different account) a few month ago with a similar problem https://forums.garmin.com/outdoor-recreation/outdoor-recreation/f/instinct-2-series/349673/instinct-2x-altimeter-issue#pifragment-1292=2

Only solution was to contact Garmin and get the watch replaced. But, now after to month or so with the new watch it seems the problem is back again, dead stable over night when the watch was new. Also altimeter did not change while taking the watch on or off the wrist. But now again, it seems it is somehow extremely over sensitive especially to temperature changes. 

Ensure your baro is also set to the current pressure.  If that is way off I could see it effecting your altitude.  I find my 2X holds altitude nicely.

Is this still an issue?  I had the same issue when I got my Epix 2, two years ago.  The altitude was all over the place.  I tried setting it with GPS, DEM and manual - no dice.  Then it would change later when I'd be in the same spot as when it was set.  This was the fix from garmin support, and it worked:  The barometer is needed for accurate altimeter readings.  Leave the watch outside for a few hours to it can match the ambient air temperature.  This sets the barometer to a baseline.  Then after that, enter in the altitude manually.  After I did this, it was always spot on.  Give it a try and report back here. One thing to note is the altimeter numbers can change if there is bad weather as that affects barometric pressure.

You cant set the barometric pressure, only manual msl, gps or DEM . 

If thats the case, the watch should compensate when you initially set it to a known altitude. I fly airplanes and msl is set prior to takeoff at a known location or the altimeter is adjusted in route via known pressure . If the watch software interacted with the known initial height the pressure differences should be compensated in the software especially since there is a barometer and or altimeter selection within the settings. Debating whether to send the watch back , one should not have to reset altimeter settings 3 or 4 times daily like i have to now.

3598346 said:

You cant set the barometric pressure

3598346 said:

manual msl,

MSL IS barometric pressure. Also called QNH. This is also the pressure indicated by weather stations.

https://youtu.be/gJuguwm7Eeo?si=glj4Ap6E0iL3dU1I 

https://youtu.be/Qc3tB98BYac?si=vnldF2OcR_-YeErM 

https://youtu.be/lRj06-MPQIY?si=xf1SHyzopttfeClP 

I think there is some mis information here.  Let me comment hopefully accurately....

• "MSL IS barometric pressure" - MSL is not barometric pressure.  MSL = mean sea level.  Has nothing to do with barometric pressure.  Its a "average height" of the sea level and from that barometric measurements are taken.
• "You cant set the barometric pressure" - You can, you can calibrate the watch and ENTER barometric pressure
• "I fly airplanes and msl is set prior to takeoff at a known location or the altimeter is adjusted in route via known pressure . If the watch software interacted with the known initial height the pressure differences should be compensated in the software especially since there is a barometer and or altimeter selection within the setting" - That is exactly why you have to set it prior to every flight... the watch CAN set itself to the current altitude based on GPS data, DEM data or manually.  The same reason you have to set the altimeter prior to each flight is the same reason you have to on the watch.  Like the altimeter, the watch after setting the barometric pressure, will read current MSL altitude pretty closely.

What may help is the barometric sensor more settings on the watch, there is Auto, altimeter only and barometer only.  Its very hard for the watch to know if you are climbing up hill or there is a pressure change.  If not in auto sensor mode perhaps try that.  Auto mode attempts to balance between these variances.

Maybe there is something in your sensor port, I find my 2X is reasonable in accuracy.  Its a watch, moving about during the day, in and out of cars, builds etc.  If the altitude is within 50 or 100 feet I think that is amazing esp when its based on pressure.

Here is what I would suggest, Calibrate your ALTITUDE.  Open the Altitude display then press the GPS button and select calibrate elevation using DEM reading (from on the ground while outside).  Then when prompted, enter the baro pressure.  You can obtain it from the nearest airport.  Find the airport ID (4 letters starting with a "K".  Ex. KBOS = Boston enter it from this site: https://aviationweather.gov/data/metar/?id=KBOS&hours=0&decoded=yes.  There you will find the barometric value under "Pressure (altimeter)".

I hope this helps and stabilizes your readings.  OK go gentle on your comments..... everyone is cool here just trying to help out.