Fenix 6 Pro factory barometric pressure incorrect

Owned this Fenix 6 Pro for about 1.5 years but left it aside after wearing it for the first few months.

I do not recall the altitude and barometer readings having issues initially, i.e. the factory barometric pressure reading measured close to weather reports, and an offset calibration in the watch menus is not necessary.

Now taking it back out, properly charging and updating it, the watch is having an internal reading offset of approximately +3 hPa. For example, our current sea level pressure is ~1015 hPa, and with my altitude of 53 an atmospheric pressure of ~1009 hPa. However the watch is reading ~1018 if calibrated to my altitude, and ~1012 if set to 0m which should display the local atmospheric pressure reading straight from the sensor

I tried calibrating, power cycling, even factory resetting the watch to no avail. I then went to check out the test menu and saw the following:

Indeed the "Local Press" reading which should be the factory sensor value is off by ~300 Pa (3 hPa). I also noticed there's a new item of "Press Offset" on the list, which does not seem to exist when looking at other images of this menu across the forum, and more importantly, remains at 113.59 no matter what I set in the watch menus. Subtracting that from "Local Press" yields 101069.22 Pa which seems to be closer to the actual value at the time this image was taken, but still off. I wonder if anyone knows why there is this offset and if it is ever correctable? Thank you.

  • I tried calibrating

    The first question should be why the calibration did not work. Is the sensor possibly dirty ? If you wore the watch 1.5 years ago, and snutz has accumulated, it is quite possible after the time that it has settled in the meantime.

    I would rinse the sensor with a lukewarm stream of water. But not too strong.

  • Thanks for the tip. I should have made myself clearer - there's typically no issue with cleanliness as I keep it inside a drawer, and I wash it from time to time. Still I ran it through water just now and it didn't help.

    By "calibration" I just meant applying an offset within the UI, which asks if you want to enter sea level pressure. It does not change fundamentally the internal "Local Press" value that is reporting from the sensor itself - unless I'm mistaken about how the barometer work on Garmins.

  • It does not change fundamentally the internal "Local Press" value that is reporting from the sensor itself

    "Local Pressure" is the surrounding air pressure. This is not influenced by the calibration. During calibration, the ratio between "Local Pressure" and MSL Pressure is adjusted. Local Pressure = ambient pressure 

  • Correct, I understand this part. What I'm trying to say is that with calibration I can obviously use the watch without an issue, knowing that I've applied that ratio to correct what it displays in the UI. However I do not recall the watch's "Local Pressure" being off by +3 hPa from the ambient pressure when I first got it, which it now exhibits, along with that curious "Press Offset" entry that persists at 113.59 for whatever reason. The very reason I even have to calibrate the barometer instead of just the altimeter as one typically does is because of this error in the "Local Pressure", and +3 hPa is not a marginal amount.

  • Out of curiosity, what is your source for true values? I have noticed a similar difference and have a nearby weather station, but it is not updated in real-time (for us consumers of information) on the web site.

  • ambient Pressure 1002.4 hPa

    elev 36.8 m

    MSL Pressure  1006.8 hPa

  • I live nearby an airport and so METAR reports are readily available and update every hour.

  • How to get the factory barometric pressure like what you attached in the picture? I guess Garmin had upgrated some alagorithms of pressure sensor in new software version.

  • Mine also shows somehow 3hPa more. How to check this reading what you showed in the photo? Does anyone know how to force pressure correction? Reczna does not give anything, after a while and so returns as if to the factory setting

  • To access the Test mode, when the watch is powered off, hold "Down" button while pressing the "Light" button. Release "Light" but keep pressing "Down" when you see the Garmin logo until the Test menu appears. Press "Back" button to cycle through the menus until you reach "Baro Test".

    Also, have been in contact with Garmin Support. Here I quote one of the chat agents: "I was able to reach out to our engineers. They indicated that the "Press Offset" entry is related to the barometer calibration. This is offsetting to compensate for ambient Fluctuations and sounds, to keep this more closely related to the altimeter calibration. This is because this sensor is very sensitive, and would be impacted by very small pressure changes. Since this is not changing, if this is not improved by cleaning the sensor, this will likely need to be replaced."

    Looks like  is correct, they did implement some sort of algorithm to it and probably has nothing to do with the incorrect reading.