Suunto 9 Baro FusedAltitude

Jorcki

Hi,

any idea why the data of my runs with Suunto 9 Baro show super negative readings during a run? The lowest point of my run is about 2-3m from sea level, but the data shows readings like -28… The watch showed that when i started my run, the altitude was 36m (which is correct ±2m), but at the end it was 9m, even if it should be 36m because i was back at the starting point.

Shouldn’t the Fused Altitude function be correcting these things? Feels stupid to having a huge expensive sports watch with barometer on my wrist, that is showing wrong numbers.

Any suggestions on how to fix this? I also regularly auto adjust the altitude outdoors and it seems to work well. But always after a workout indoors, the altitude shows really odd numbers.

freeheeler

@JohanK
did you adjust altitude within 30min before your activity? then fusedalti is deactivated as the watch thinks you know better…
I never ever touch alti settings on my S9B and even if the start alti is wrong it will correct itself after some minutes, also backwards

Jorcki

Thanks for the reply!

Did a 12k run today according to your suggestions. No alti adjustments done whatsoever in atleast the last 24h. Just letting the watch do it’s thing.

The starting and ending altitudes seem to be pretty close to the truth (35 at start and 33 at the end. 38 is the exact reading), but mid-run altitude readings are nowhere near acceptable. Showing an altitude reading of 0m at a spot that i know is 18-20m, and altitudes varying from -15 to -29m for about 5km where i know that the real altitude is about 0m to 10m…

Really frustrating.

Mff73

@JohanK
It is high time to make a serious cleaning of your baro sensor.
Absolute value is one thing, but such changes are not normal.

freeheeler

@Mff73 @JohanK
…or double check the tightness of your strap…
if your moist arm is covering the sensor holes and seal them you can be happy if the wrong values are tiny like that…
as @Mff73 said, clean the sensor and try to wear the watch one step looser

Jorcki

The weird thing about all of this is that i bought the watch in late 2018 and didn’t experience any kinds of problems with it before a couple of months ago when the altitude readings started to get very odd. Before that the readings have always been perfect. The readings were most of the time also correct on the home screen, but nowadays its jumping all over the place…

I have always worn the watch with the same tightness around my arm i wouldn’t think that it would be the thing that is causing the problem. But thanks for the suggestion!

I will try to clean the sensor now because it sound like something that possibly could be causing the problem! Any good suggestions how to clean it in the most effective and efficient way without harming anything?

Below are the readings if anyone is interested. All negative readings are wrong as the lowest altitude should be around 0-10m.

Screenshot (17 May 2020 11_19_58).png

freeheeler

@JohanK
soaking in warm water and maybe some drops of soap (that’s what I do). and I’ve read that a baby toothbrush (or any very soft toothbrush) could help, too, in case only soaking and flushing does not help

isazi

@JohanK said in Suunto 9 Baro FusedAltitude:

The weird thing about all of this is that i bought the watch in late 2018 and didn’t experience any kinds of problems with it before a couple of months ago when the altitude readings started to get very odd. Before that the readings have always been perfect. The readings were most of the time also correct on the home screen, but nowadays its jumping all over the place…

Not exactly weird, if it was working and it’s not working anymore there is something amiss. First try to clean it, soaking in warm water and moving it around a bit. Then rinsing with flowing water. If it does not help, and your watch is under warranty, maybe a call to support to see if they can help.

Jorcki

I have always been washing the watch after use, and the holes on of the barometer are clean, so i could not believe it was any dirt that would be causing the problem Did all the washing with a toothbrush and soaking in water for a couple of hours with some drops of soap but the problem still persisted.

I contacted Suunto customer support via Facebook and they told me to have the watch soaked in water overnight. I took the watch straight out of the glass of water that it was in, dried it with a towel and went for a short jog this morning and i couldn’t believe it, but he problem was long gone. The altitude readings were perfect, and as precise as they used to be earlier! Problem solved! The soaking of the watch overnight in a glass of water is of course something that could be added in the Suunto 9 Baro User Guide, for future reference to ease the progress for someone experiencing similar problems.

Thanks everybody for the help.

Screenshot (20 May 2020 07_56_22).png

Jorcki

But on the home screen the altitude shifted from being a while after the run at the correct level of 49m suddenly flew me up to almost 100m while sitting at my work desk. So lets see what happens.

freeheeler

@JohanK
do you work from home or in the office with aircon?

Jorcki

@TELE-HO From home, no aircon here.

The readings from workouts have now been ok.

It seems like the watch doesn’t recognize the changes in air pressure correctly (as changes in elevation or just air pressure) in other than sport modes. If i choose to display the altitude on the “home” screen it might change by 20-40m while just playing petanque in the yard, even if i “auto adjust” the altitude with gps before the play.

Haven’t received any storm alerts in a really long time either.

If i have understood correctly, the watch should be able to know if the pressure changes are due to elevation changes or just air pressure changes if staying still?

zvonejan

@JohanK said in Suunto 9 Baro FusedAltitude:

@TELE-HO From home, no aircon here.

The readings from workouts have now been ok.

It seems like the watch doesn’t recognize the changes in air pressure correctly (as changes in elevation or just air pressure) in other than sport modes. If i choose to display the altitude on the “home” screen it might change by 20-40m while just playing petanque in the yard, even if i “auto adjust” the altitude with gps before the play.

Haven’t received any storm alerts in a really long time either.

If i have understood correctly, the watch should be able to know if the pressure changes are due to elevation changes or just air pressure changes if staying still?

I like this post, and you are correct. This setting is missing in newer watches. On ambit there was option to chose: automatic, (less than 5 meter in 12 minutes is weather change, everything else is movement) barometer, ( all changes are weather changes) altimeter (all changes are movement changes)

Dimitrios Kanellopoulos

@JohanK sometimes after soaking the component still has humidity. It can cause this.

Maryn

@zvonejan now in S9 baro is 3meter in 12 minutes or more?

tomahawk5000

I live in 4th floor on my flat. Now I have 249m but sometimes I have 253 and once I had over 270

cosme.costa

@Marcin-Byrtek said in Suunto 9 Baro FusedAltitude:

@zvonejan now in S9 baro is 3meter in 12 minutes or more?

This It is not really clear to me and I’m pretty sure the algorithm behind the altitude is more complex than that. I mean, if I check my moves I have:

running: Ascent 86 m not multiple of 3 / 117 m multiple of 3 / 80 m not multiple of 3 …
Trail running: Ascent 440 m not multiple of 3 / 414 m multiple of 3 / 614 m not multiple of 3 …
Hiking : Ascent 169 m not multiple of 3 / 107 m not multiple of 3 …
Walking: Ascent 85 m not multiple of 3 …

These are random examples, I think that the 3 m are only for kick in the “counter” but once it is counting it is not done in stacks of 3 m.

cosme.costa

@tomahawk5000 said in Suunto 9 Baro FusedAltitude:

I live in 4th floor on my flat. Now I have 249m but sometimes I have 253 and once I had over 270

I think this is important relatively. The watch measures the altitude using the baro sensor, so pressure changes in our home can happen and the watch do not have GPS to check if the altitude is correct. What in my opinion is good, is that the values that you have are quite near among them, of course some days some of them can be way off.

On the other hand, during some activities is the altitude important? I mean if I do some trail running or some MTB it is important that I the altitude starts at 200 m or 400 m? what in my opinion is important is that the total ascent/descent during the activity is correct. Is for that that I do not like to much that Fusedaltitude can correct during the activity not correcting the previous altitude, I’ve seen it a few times, only a few. It also bothers me that sometimes when your run starts and ends in the same spot the altitude values are not the same. But I have to say that I’m mostly happy on how it works and I never set altitude manually.

I like how my bike gps with baro works regarding this, you can set manually the altitude, not fusedalti, or you can do your move and when you finish you can correct the starting point altitude in the app and all the graph will be corrected regarding this.

vr2udt

@cosmecosta I suppose if there is no significant weather change, i.e., mercury relatively stable, in the duration of the exercise, manually setting the initial altitude reference may be more preferable, or leave it alone as you mentioned ascend/decend values are all we need to know. But if ambient pressure is changing drastically from weather, GPS assisted FusedAlti could come in handy. Seems the only way to turn off FusedAlti is to disable GPS, using it indoors as a pure baro based instrument.

Pavlas

Hi,
I have a very similar problem as @Jorcki
I mentioned it here.
Two days ago I tried to clean the sensor (I left the watch in water all night and in the morning I tried to clean it with a vinyl record cleaning brush, which is VERY gentle). The problem with the hairy graph is the same so far. But now I notice that the altitude changes by itself. I put the watch on the table tonight. It showed 271 meters. In the morning I picked it up and it still showed 271 meters. But within a second, the altitude dropped to 265 meters. Then with a shake, it changed again by a few meters.
Maybe I released some dirt that’s still in the sensor?
You recommend cleaning it with a baby brush. Should I use the brush to clean only the holes or reach inside the hole? (I assume not inside)