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The altimeter gives me wrong values

Former Member over 5 years ago

Hello people.

I went from Garmin 235 to 945 to, among other things, have greater precision in the unevenness that I was running in my races, both asphalt and trail.

With 235 it has happened to me that on a completely flat route then, seeing the profile of it, I took unevennesses of 25-30%, which is unreal and I guess it was because it passed through mountain areas where there was hills nearby and the system interpreted that he climbed them, but no.

The fact is that I went to the Garmin 9445 in the certainty that, having a barometric altimeter, these erroneous data would be lower.

I already know that the technology we can wear on a watch is not perfect, but I thought it would give less problems.

I do not know if we have to take previous steps that I am not fulfilling. I just look at the height of the area from which I want to start running on websites like www.daftlogic.com/sandbox-google-maps-find-altitude.htm

Normally it is the same always, close to home and is 4 meters above sea level.

With that data I am going to calibrate the Altimeter in Configuration / Sensors and accessories / Altimeter / Calibrate

He asks me if I want to put the current height (4 meters), I say yes, I accept and I already thought that would be enough, but the fact is that sometimes on the route I get negative values, below sea level , which is impossible, and others, when I return to the place of origin, it records me -50 meters, for example.

I repeat, I do not know if it is necessary to do some more operation, but if it is something that I have to assume as normal, then I would have stayed with 235, which I just learned now that it has automatic height correction, that we have to activate and I did not have.

Sorry for this long message and sorry for my English taken from the google translator, but the 945 is desperate for me on this topic (in others it is great), to the point that I thought about selling it and getting the new 245, without barometric altimeter but with height correction and other functions, such as being able to handle my Stryd pedometer well

Thanks in advance, but I would appreciate some kind of light on this issue and how to make at least not give me so many wrong measures.

Regards, Juan

0 tess over 5 years ago

If possible, calibrate the elevation and the barometric pressure to the correct value in the same environment you'll be doing the activity. It sounds as if you're calibrating the elevation, but then the barometer is rising which the watch will interpret as a loss of elevation.

0 Former Member over 5 years ago in reply to tess

And how do I know the barometric pressure I am at?

Thank you.

0 Former Member over 5 years ago in reply to tess

I see that the average pressure at sea level in Hectopascals is 1013.25 hPa and that it decreases an average of 1 hPa every 8 meters high.

So should I put that data, conditioned by the height I am at?
That is, if I am, for example, 40 meters away, subtract 5 hPa

Is that so?

0 tess over 5 years ago in reply to Former Member

No. Pressure will change due to weather. I use a website (weatherunderground) that shows all the weather stations near me with the current conditions.

0 Former Member over 5 years ago in reply to tess

Thank you very much for the information.
Does the information that provides pressure every hour refer to sea level?
Should I vary that data based on the height at which I am?

0 Former Member over 5 years ago in reply to tess

Ok, I already answer.
The value given by the page is the pressure value at sea level in that area and that is what you have to put in the barometer configuration in the clock.
Thank you for everything, and sorry for my ignorance on that subject.
Regards, Juan.