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Altimeter issue

Leew72
over 6 years ago
Anyone else getting false elevation reading on the 645M ?? Mine is consistently overestimating by 600ft.. any way of calibrating this???
  • Former Member
    0 Former Member over 5 years ago
    Where can I find this?


    You can find the manual calibration in Settings>Sensors & Accessories> Altimeter> Calibrate
  • 0 over 5 years ago
    Go to Settings>Sensors & Accessories>Altimeter
  • 0 over 5 years ago
    Start an activity and on Altimeter data screen hold UP.
  • 0 over 5 years ago
    Still not working for me the elevation gain with the new firmware.
  • 0 over 5 years ago
    This morning I did my first run with the 3.7 firmware and I used the new calibration option. I started the activity, waited on a GPS fix and then accessed the calibration option via the up button. I used GPS for calibration and it came up with the correct altitude automatically. That makes me wonder why the automatic calibration on earlier firmware release did not work, because that was using the GPS sensor (3D fix) as well for determining the altitude. Let's see what happens next time. I am very glad Garmin added the option though, so I always have the option to manually set the correct altitude in case the 'GPS method' has it wrong.
  • 0 over 5 years ago
    This morning I did my first run with the 3.7 firmware and I used the new calibration option. I started the activity, waited on a GPS fix and then accessed the calibration option via the up button. I used GPS for calibration and it came up with the correct altitude automatically. That makes me wonder why the automatic calibration on earlier firmware release did not work, because that was using the GPS sensor (3D fix) as well for determining the altitude. Let's see what happens next time. I am very glad Garmin added the option though, so I always have the option to manually set the correct altitude in case the 'GPS method' has it wrong.


    For me at least the problem was, that it was stuck with a previous altitude in front of my house and it wouldn't change. In the end because of the weather changes in the meantime, the difference was almost 30 meters and it just wouldn't update. Now i did the GPS calibration from the altimeter menu and it was perfect during my long run
  • 0 over 5 years ago
    Software version 3.70.
    Promising/improved... First 2 x activities start and finish elevation within 5ft of initial 'calibrated' value.
    Will be interesting to assess repeatability of hill repeat elevation profiles.
  • 0 over 5 years ago
    I was on the top of an 1188 feet hill today and the 645 still on 3.40 agreed with this figure however the overall elevation for the activity was approx 100 metres too high
  • 0 over 5 years ago
    I've had the chance to do a decent mountain bike ride with the new FR645 firmware v3.70, comparing to my Edge 520. It looks like the update over v3.40 has fixed the elevation issues that I faced. See previous posts #212 and #218 for elevation issues on v3.40.

    53km ride and both the FR645 and Edge 520 were connected to the same Ant+ speed meter on hub and external HR strap.

    '1 second recording' on both devices.


    Edge 520: 932 vm
    FR 645: 945 vmciq.forums.garmin.com/.../1394220.png
  • 0 over 5 years ago
    Have you uploaded the same image twice?