Barometric pressure difference
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@Stefano-M64
I am cleaning my SV sensor regularly, but now when weather is quite warm my Verical shows around + 5hPa against nearest professional Czech Meteorological Institute weather station which is 5 km from my home. Strange is that in winter when it was cold they displayed the same value as the station. My wife has Race and and she had the opposite problem. In winter Race was off by -4 hPa and now when is warm it is O.K. And at the same time, I don’t feel like they measure ascent and descent incorrectly. Temperature sensor in both watches look also O.K. -
@PetrMisek the point is simple, we cannot expect that the consumer baro sensor of our beloved watch can be precise and stable (that is, not drifting) as the professional ones. In our lab we have one good reference barometer that was paid about 4’000 euros (ten times the price of my Race), and there are for sure more expensive models. In any case, also professional barometers need to be tested and re-calibrated.
Nevertheless, all the metrics we need are computed by means of pressure differences, so the absolute value is not that important. -
@Stefano-M64 yes yes I know that, I wrote this just for fun, because it also depends a lot on the ambient air temperature
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@PetrMisek maybe there is also an option to calibrate the sensor, does anyone know? I think that for the S9B this option was somewhere in the service menu
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I think there is room for improvement in the way the watch calculates altitude and pressure . For instance leaving the watch idle for some days one can observe that the altitude changes while it shouldn’t be the case … I assume the watch misjudges the changes in barometric pressure as altitude variation despite the fact there is no movement .
In ambit 3peak times there was an option to define those changes as altitude or barometric or automatic …
Unfortunate in recent days this is not the case -
I work in metrology laboratory, so I tested all my watch
. I compared Garmin Fenix F7 and lately F7Pro with some Huawei and Amazfit. Garmin was the worst, but only one or two hPa. But that doesn’t matter at all, if there was an option to manually enter sea level pressure and altitude. And even without that, it works normally, the trend is important.
Now my Race shows almost spot on with the etalon, if I set the altitude to zero, because the etalon measures ambient pressure.I found the link:
https://forums.garmin.com/outdoor-recreation/outdoor-recreation/f/fenix-7-series/340572/f7-pressure-laboratory-compare-just-for-fun -
@Jan-Suchánek Nice tests! As a scientist I deeply appreciate the data over anecdotal reports.
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@Jan-Suchánek I have SV, SR and S9P. I compared all 3 with professional CHMU weather station near my home, all 3 were almost spot on, but SV is now way off, it is showing around +6 hPA more than the others… and also altitude measuring is quite unstable. So it looks like sensor problem (sensor is clean as new)…
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@PetrMisek my Vertical was very unstable few weeks ago, with altitude changes visible in the 2 hours graph. Got the sensor changed and now is working as expected again.
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@isazi Great to read that, It’s similar with my watch and the barometer deviation was increasing.
