F7 pressure laboratory compare just for fun

Baro/tmp sensors vary in precision and accuracy (example BMP180 ±0.12hPa). Until we know what type is fitted in the Fenix 7 we can't get the data sheet and figure out what its specifications are. Anyone with inside knowledge is invited to share ;-)

Usually my Fenix 6 and 7 show the same baro values as long as they were calibrated at the same temperature in the same environment as they are used in. Outdoors they can differ a liitle, but overall I am impressed with how well they seem to agree. 

The accuracy of BMP180 ±0.12hPa is good enough. I believe, that accuracy of Fenix is ±same or better, but the value is shifted of same amount at all measurement points, so if there will be an offset possibility in calibration menu, it will solve that. ±10hPa with 0.1hPa step will be sufficient. Maybe ±5hPa will be enough ...

Already suggested to Garmin. :-)

honza_81 said:

the value is shifted of same amount at all measurement points

Some watches (for example Instinct 1st gen) had the possibility to calibrate the altimeter (altitude only), and the barometer (MSLP + altitude) independently, hence I assume it was used for adjusting the offset. Instinct 2 does not have the barometer calibration option anymore, and I suspect that other newer models either, but it may be worth of rechecking the menus of your F7 (I do not own it), just in case. If not, I recommend contacting the Support and request a replacement, or a recalibration.

Perhaps dirt or moisture in the sensor port can cause some deviation. So you could try cleaning and drying it, and then rechecking with the lab device again.

You can also try requesting the barometer calibration option at Share Ideas | Garmin, but seeing they removed the existing option relatively recently, I am afraid they are not going to bring it back easily. And I understand why - people often made their altimeter unusable by entering incorrect or inaccurate data, and it then led to too many complaints and support cases. Normally the factory calibration of the offset should hold over long time, and there should be no need to do it again and again.

trux said:

Instinct 2 does not have the barometer calibration option anymore, and I suspect that other newer models either, but it may be worth of rechecking the menus of your F7 (I do not own it), just in case.

Well... I may very well be misunderstanding something, but my Instinct 2 Sol Tac, Instinct 2X Sol Tac, and Instinct Crossover all have Barometer calibration.

Go to Barometer Glance/Widget

Press Upper right button

Select Calibrate

Select Enter Manually

Enter Elevation and press the upper right button

Enter Sea Level Pressure? Select Yes

Enter Pressure and select Done

This simple procedure allows one to enter separate Elevation and Pressure values.

My tactix7 also allows this separate calibration.

What am I missing?

gaijin said:

What am I missing?

Ah, yes, you are right, it is still there. I did not complete the manual calibration, and mistakenly thought they replaced it by the plain altimeter calibration, since the first step was just the elevation calibration. I had the feeling it was in the reverse sense on my old Instinct, but then, it is a couple of years I did not use it, so I may be wrong again. 

Yes, that's same in F7. You can separately enter elevation and sea level pressure.

honza_81 said:

Yes, that's same in F7. You can separately enter elevation and sea level pressure.

And did you try it for fixing the offset of 2 hPa ?

So it means it does exactly the same thing as entering the elevation during the calibration? That makes little sense, but frankly told, I rather expected it.

Yes, so if You know the right sea level pressure and elevation of your position, you could set it absolutely right and should get right numbers of elevation and SEA LEVEL pressure after that. (If the algorithm was perfect, but it can never be.) These two values are independent WHILE calibrating. So this type of calibrating could deal with ambient pressure sensor offset, but ambient pressure value will still remain with offset.

But almost nobody needs to check the ambient pressure in real life. Maybe because of weather in hills, but in that case, if I'll stay in same elevation for a day, I could switch the barometer mode to "barometer only".

Next case is me and laboratory compare :-).

Tomorrow, the temperature chamber exam is waiting for my F7 :-). I'll try whole operating temperature range.