Bumpy and inaccurate altitude data with new Suunto 7

[Dimitrios Kanellopoulos]

@themrdjj send it again and pm me with the case number if it still does not work ok.

[daltonthomas]

Just for information, i`ll get my watch back the next days. I got following information from service.

“Dear customer, I have replaced your device with a replacement unit that will come with a three (3) month service
warranty, which applies if the original devices warranty has expired”

I`ll let you know how correct the sensor is working as soon i did the first tours.

Cheers.

[themrdjj]

@Mff73 I haven’t compared it with another Suunto 7, just with my old Polar watch, my phone’s data and the Strava-corrected data. I will do more tests this week and pay even more attention to wearing it correctly, let’s see.

@Dimitrios-Kanellopoulos Will do, thanks!

@daltonthomas That’s good to hear!

[Mff73]

@themrdjj
Sorry, i mixed with @daltonthomas

[freeheeler]

@Mff73
me too

[themrdjj]

Here’s another thing to try out. Can some of you who have a S7 please download this app :https://play.google.com/store/apps/details?id=de.taxilearn.phi.hoehenmesser and compare it with the following video of what it looks like on mine? The amplitude of the pressure change seems to be around 0.1-0.2 hPa.

https://youtu.be/sD4pk6ZnfZ0

[pilleus]

@themrdjj my S7 is jumping between 972,88 and 972,92 hPa. I calibrated to the correct pressure at sea-level.

The identical amplitude on my Casio WSD-F21HR and Skagen Falster 3.

[themrdjj]

I did some more testing over the last week, here are some altitude profiles where I compare the raw data from the S7 to the Strava-corrected data (the colours are mixed up, but it’s clear which one comes from the watch). Sometimes it’s worse, sometimes better, but the overall magnitude is wrong and it’s pretty bumpy (and no, those bumps are definitely not correct).

I made sure that the watch was always synced and I did frequent reboots as well. I always waited at least 1-2 minutes after the GPS connection was found, often longer. The GPS tracks in all of these activities were pretty good, so the GPS certainly isn’t the problem.

While wearing the watch (on my left arm, a few cm away from the wrist), I always made sure not to cover the barometer hole. I don’t sweat much either, don’t have very hairy arms and didn’t use the watch in muddy or particularly wet conditions, so I’m quite sure that the barometer itself just isn’t working properly, perhaps in a way that is overlooked during the standard Suunto lab tests.

I’m sending in the watch again this afternoon. @Dimitrios-Kanellopoulos I’m going to send you the number by PM now.

@daltonthomas Any updates on yours?

[freeheeler]

@themrdjj
good luck, dude!
I hope they find the issue or at least change the sensor

[daltonthomas]

Hello,
today my wife tested the watch back from service with new replacement unit.
Because bluetooth adress changed, i believe really the unit was changed.

Its unbelievable, the first tour ( she climed a mountain from 841 m altitude to 1516 m altitude), the watch showed 3824 m ascend and 3832 m descend. She wore the watch correctly on her left arm.
We are starting of thinking that we are too stupid in using a Sport watch correctly…:)
What we know is that the last 5 years with the Suunto Ambit2, we never had issues with the altitude.

Enclosed the more detailed data of the track. I have no idea how the wrong data comes from because the altitude itself is more or less correctly (apart from the descent-parts during climbing up). During the tour the data of the watch was not checked, therefore i don`t know when the wrong altitude started.

Data of the track:
https://quantified-self.io/user/rxqh5UVb9LhOn2n6zRIh2gHKXMH2/event/9gLkppcytWZHY1uCZMnx

[freeheeler]

@daltonthomas
if you zoom in you see a lot of spikes in the alti graph. I saw something similar today with my S9B. Wet condition, watch worn relatively loose on the wrist with the body over the jackets cuff.
It gave me 721m instead of reality around 520m.

Back to “if you zoom in”: you gain over 27m within 20 seconds. This would result in over 4’800 meter per hour
Maybe something covered the sensor unintendedly.
I would give it some more tries

[themrdjj]

@daltonthomas So you think you received a completely new watch? That altitude profile still looks really bumpy (I assume it wasn’t actually this way IRL). Could you maybe also post a comparison with the Strava-corrected profile? (in case you use Strava)

A few hours ago, someone else with the same problem posted about it on Reddit: https://www.reddit.com/r/Suunto/comments/kxwp6q/suunto_7_faulty_altitude_measurements/

[daltonthomas]

@themrdjj
I am sorry but i am still not using strava. The track is completely without any descent meters, not as showed in the bumpy altitude track from my S7.
Thanks for the Reddit discussion, it seems that more people are suffering with that issue.

I found out that the way the watch is used influences the altitude measurement (wearing on left or right hand, attaching on backback). I guess this is because of the coverage of the altitude measurement hole.

@freeheeler
Thanks for the zoom (didn`t know zooming function in quantified itself…:)), now its clear where the meters are coming from.
The next will be a test in variation of the watch fixation (loose, strong).

[freeheeler]

@daltonthomas
it would be interesting to know if the spikes come from wearing style or if anything else is the root cause.
…but wearing it on the backback as default, I’m not completely sure if this goes beyond the use case

I don’t want to wake up sleeping dogs and I don’t want to make a big story out of it… but I mentioned some time ago that I personally think that especially S9B has not the very best position of the baro sensor and holes. I was the biggest fan of the A3PS baro sensor position and design! I found the design of S7 was slighy better than on S9B, but I might be wrong.
The design of both S-liners might be very good for most of “real” athletes who have arms like Kilian. I do not have the same athletic shape as Kilian has, hence also a bit bigger arms and wrists and blocking baro holes is way easier for me than for a BMI <20
But it is what it is now.
…and shhhh : I once saw pictures of the S9B housing design and thought about reworking my watch in order to make it less prone to baro holes covering/sealing.

[daltonthomas]

Not really new information.Today similar situation, i did a ski-tour together with my wife. She used the suspicious Suunto7, attached strongly on her left arm and i used the black Suunto7. Totally different data.

https://quantified-self.io/user/rxqh5UVb9LhOn2n6zRIh2gHKXMH2/event/NJi4iiYz0oRMXiM5KI0h

[freeheeler]

@daltonthomas
I hope you’ll be ski touring tomorrow, too… and just for the hell of science, could you both wear the watches very loose and ignore the HR results? Or even put it on your backpack shoulder strap?

[daltonthomas]

@freeheeler
Tomorrow the conditions are not so good, i guess we are going to stay at home. Next event it`s planned to change the watches and then we are going to wear the watches loose.

[daltonthomas]

Thank you all for your great help in finding the root cause of the bad behaviour of my Suunto7.
At the end I found out some tricks like attaching the watch to the backpack, fix the watch very strong on my arm to get better altitude results.
Because thats not the way i would like to use this watch i decided to look for another sport watch or go back to my old Ambit2.
Cheers and again thank you
Thomas

[freeheeler]

@daltonthomas
hmm… unfortunate to read that…
I would have preferred that the forum and the guys at Suunto could find a solution on that.
But eventually you need to be happy and focus on the activity you like rather than messing around with technology.
Enjoy the sports

[themrdjj]

Perhaps I should also give an update. I think the results were a bit better after receiving the new watch, but still not as accurate as I would have expected.

Anyway, I stopped caring about this, to be honest. I don’t really use the altitude profile in my training anyway and if I ever decide to do so then I still have the Strava correction (I only use Strava to analyse my activities anyway). Also, the comparisons I made in the beginning with my old watch were a bit unfair because there the Strava correction was applied automatically (as it doesn’t have a barometer), so I never got to see the raw data anyway.

I really like everything else about the watch and maybe I’m just expecting too much from it (my OCD wanting perfect data). So for now I’ll keep using it, until it’s time for a new watch.