Altimeter way off

I used to have the Forerunner 235 and the elevation on my run stats were always spot on. I recently got the 5Plus and running at the beach bike path in Southern California says my elevation start was at 180ft! It should be about 10ft. And during my 8 mile run it was all over the place going from 160ft to 230ft.

what is going on? I have it set for GPS+GLONASS. I used to have it just GPS thinking if I added GLONASS it would be more accurate but it’s the same, if not worse.

Anyone have any suggestions???

tia!

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0 Former Member over 5 years ago

Your 5+ has a barometric altimeter and you need to calibrate it often. Your 235 was "spot on" because it didn't have a barometric altimeter and it was using geographically surveys based off your GPS track. There's different settings you can try on your watch to see what best fits your needs.

https://support.garmin.com/en-US/?faq=J2WVA0dss82BNpphPYWq56&productID=603267&searchQuery=altimeter&tab=topics

0 Former Member over 5 years ago

The forum posted my answer twice for some reason.

0 Odie21 over 5 years ago

Also, you can use DEM as a way to calibrate it as well. I find that it’s nearly perfect (I test it often). No ALT/BARO sensor will be perfect 100% of the time, that’s why I said months ago that the DEM feature on the 5+ series is one of the most underrated features on the 5+ series.

With this feature, this makes the the 5+ series the only ABC watch that can truly give you proper information via all 3 sensors.

0 Former Member over 5 years ago in reply to Odie21

Odie21 said:
With this feature, this makes the the 5+ series the only ABC watch that can truly give you proper information via all 3 sensors.

Add the 945 to that also.

0 Dr Phil over 5 years ago in reply to Former Member

And the Marq too...

0 Finnatical over 5 years ago in reply to Former Member

Would Auto Calibrate work?

If I manually calibrate it how would I know what elevation I’m at?

0 Finnatical over 5 years ago

I think my watch is defective. I’ve tried auto calibrating and also manually calibrating it. Thankfully I was at sea level so I had a pretty good idea of my elevation! I’ve tried all of your suggestions (thank you, BTW) but it all over the place on my run, like 180 ft then it would go down to -15ft below sea level! Ugh!

I’m thinking I must be doing something wrong. I don’t want to believe that my watch really is defective. I actually just don’t want the hassle of returning and getting a new one.

0 kitedavo over 5 years ago in reply to Finnatical

I have a new 5x plus and I was having the same problems. I hike market peaks in Japan, They're marked to .1 of a meter so I know they are very accurate. I've been checking the altitude as soon as I stop it's been way out and it can be either way. I've been calibrating it everywhere I can for 2 months now, wherever there's a concrete maker for elevation in the mountains I calibrate. Yesterday I hiked a 678,9 meter peak and it read 678 meters but I checked after about 5 minutes after stopping.

Might be something to try ( wait a while before checking and calibrating ).

Now I don't know if the waiting thing was a factor, however, I'll test tomorrow if I can get up the mountain and let you know.

0 Former Member over 5 years ago in reply to Finnatical

GPS can have a margin of error of + or - 400 feet for vertical measurements. Manually calibrating is always best. If you have your cell with you there are countless sites that will show your current elevation. You can get the elevation from a map, or calibrate using DEM. I always try to calibrate both my altimeter to the correct known elevation and the barometer to the current pressure prior to starting an activity. I then leave my watch on auto calibration which will switch between altimeter and barometer modes. For the most part it works fairly well.

www8.garmin.com/.../GUID-53F2E412-E939-4B29-B5B3-3F3CCAA0ECAB.html

0 Finnatical over 5 years ago in reply to kitedavo

I know it takes a while for the altitude result to display on the watch face, but when I upload my run to Garmin Connect the elevation graph shows it’s off. I always run out and back on a particular path at the beach and it’s been showing a continual downhill starting at 180ft. but the graph should be like a mirror image of itself since I’m running out and back.