Elevation problem

Former Member
Former Member

HI

I did read a lot of discussion here:

elevation-consistently-inaccurate-reading-too-low

problem-with-barometric-altimeter

altimeter-issues-in-the-rain

Looks that I am not alone who has problems with elevation. Problem which happen in my case is ONLY during activity. I also think that there are several different problems.

#1

I did check pressure and elevation graph in watch during the day (holding ABC and scroll), values were OK. I did compare pressure with my weatherstation and very close national weatherstation. I did stay at home during all day so altitude was same but elevation in watch change a little (+-5m).

I did start mtb ride at 5:30pm and for 1h ride I did make cca 17km. I did make several small up and down hills. Before I did stop activity I did see that elevation is not correct because I did start and stop almost at same place.

Here are graphs just after I came home:

you can see that elevation at the end is higher. I did start at 228m and stop at 264m.

pressure graph, I was SHOCKED, how pressure can change so much, cca from 1016 to 1022. I did find out that it happen during descent.

I did check my local weather station:

I also check national weather station, and there is also nothing strange. I did put marks to be able compare with watch 6 hours graph. I think, there is something wrong with sensor or with firmware of Instinct.

I did export activity to GPX and then enable elevation correction in web and export that too. Here is comparison

Blue is original GPX with elevation based on barometer. Green is GPX which has elevation correction enabled.

The significant change start at cca 0.55h = 33min of ride during normal descent.

In other threads someone mentioned sweat can make some problem. And there is also thread where rain is mentioned. Do you think that this can be problem in my case? It is 4 hours after I finish my activity now. Watch still showing wrong values of pressure and elevation. If it is problem of sweat or water then how long it takes to dry? or is it going to correct itself?

#2

What I also know is that instinct is slow in elevation reading.

I can see that in fast descent. Another day I went slower on downhill and also slow down before next uphill. Results was quite OK. Of course, barometric altimeter will not catch all small hills.

Settings:

- altimeter auto cal = off

- barometer watch mode = auto , Tell the true, I don't understand this settings clearly.

thanks for any comments

  • Just orderd it on shapeway, altough shipping quite expensiv.

    Other printer service provider are not be able to print it.

    Thanks to thomass001

  • it doesn't really work any better so far, even though I'm using the clip.

    Here the height of a run. Start and stop are in the same place in reality...

    Maybe it would be better with another firmware, 16.50 is not really good.

  • So try the 16.91 , "Improved altimeter accuracy".

    I test it for a week now, I can't say if it is really better so far.

  • I'm on my third Instinct, all conventionally charged.  The first two went back due to constant problems with elevation readings, IE wild, unrealistic variations.  This represents about three years of use, total.  They would show me anywhere from -250 feet to +250 feet from day to day.  I'm on the coastal plain of New Jersey and at an elevation of about 69 feet.

    I bought the clip to see if it would cure the problem.  To be honest, it did alleviate it somewhat, but the clip was beating the heck out of my wrist bone, so it's sitting in a box along with some spare bands for the watch.

    I've come to the conclusion that the altimeter function is more of a toy than anything close to accurate.  I do like the Instinct, I just don't bother with the barometer or altimeter functions anymore.  They are not reliable at all, clip or no clip.

  • Hi can you share with me the stl file too.

  • Hi guys,

    I bought my solar instinct in febraury this year.

    The same day I updated it to 16.50 firmware.

    In My case all work fine, altimeter was incredibly accurate.

    I ride my bicicle and normally I go from point A to point B and then I came back, so altimeter graph should be simmetric and it was!

    I wear my instinct on the wriste, but not cover it by clothes to see speed.

    I gone to the mountain by car, i slept in a house to 800 meters and the day after altimeter was calibrated automatically and correctly to 800 meters.

    I Drive to 1.675 meters and istinct shows 1.676! very very happy!

    Then arrives april and temperatures go up. My skin sweats.I ride my bicicle, altimeter graphs are no longer simmectric.After half way, altimeter register a wrong altitude.

    Also if i go to walk around my little town, altitudine is not accurate as before. if I keep the watch not tight, situation improve: altimeter go better.

    This morning i ride my bicycle, but I put the watch on the handlebar. I give up on the heart rate monitor, but I was curious see altimeter graph at the end of activity.

    ALTIMETER GRAPH WAS PERFECT! Incredibly perfect and simmetric (from A to B = from B to A)

    Heat, sweat and tight strap causes the close of holes (ther are two holes) of altimeter sensor. Also skin umidity induces a bad read of altitude.

    You can try to close one of two holes with a finger and see altimeter go down immediatly.

    Position of two holes is unhappy position.

    In normal situation (no sport activity) you can use your strap without tight too mach. The Watch have to move on tyour wriste. hear rate monitoring go well.

    During activity (in my case bicicle) is very better use watch on hadlebar. I think to buy a heart band.

    I'm curious to try thomass001 gadget.

    @ thomass001: could you share with me the stl file? I'll try to print and I'll post here results in normal use and use during an activity.

    Thank you very much!

    Bye

    DIDAC