Suunto 9 Baro FusedAltitude

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)

Mff73

@pavlas said in Suunto 9 Baro FusedAltitude:

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)

do a fridge test (search forum), if you baro sensor is sensible to temperature you may face this behaviour. I had this in the past with one SSU, even perfect cleaning didn’t change anything, sensor was defective and watch was changed.

Pavlas

@mff73 Thank you! The temperature looks fine to me. According to the graph, it’s running smoothly. No abnormalities.

freeheeler

@pavlas
@Mff73 suggests that you perform the fridge test. it doesn’t say if temperature shows correct. what it does is to make a defective baro sensor visible: when the temp changes and the altitude changes accordingly, then the baro sensor has issues.
If I remember correctly slight changes are normal, but massive changes would point to a baro sensor malfunction

Pavlas

@freeheeler Yeah, the watch is already in the fridge and cooling

Mff73

@freeheeler
Exactly this, I wrote this too quickly

Pavlas

So here are the results of the fridge test:

Altitude: 226 m
Pressure: 1037 hPa
Temperature: 29°C

After 30 minutes in the fridge
Altitude: 229 m
Pressure: 1037 hPa
Temperature: 5°C

After 30 minutes on the hand
Altitude: 221 m
Pressure: 1036 hPa
Temperature: 27°C

Egika

@pavlas looks ok to me.
But both “hairy graph” plus “shaking leads to altitude change” makes me think the baro sensor is influenced by movement.
Maybe something loose inside (either parts of the sensor or debris).
This is nothing you could probably repair yourself. If soaking the watch and flushing it under running water does not help, I would send it in for service…

Pavlas

@egika Thanks! I’ll try a few more cleanings in water and night bath.
I’ll try a baby toothbrush (hopefully my daughter won’t see me).
And just to be sure, I’ll ask again - should I use the brush to clean only the holes or reach inside the hole?

isazi

@pavlas I never reach inside, just clean the holes.

freeheeler

@pavlas
when she sees you, next time you say: go and brush your teeth, she’s cleaning her watch
…sensitive question regarding putting things into the baro holes… I have a very soft toothbrush (similar to kids toothbrushes) and cleaned the holes without thinking how deep the brushes go… I assume it does not harm.
In my simple imagination sand grains entering this holes are more harmful than a baby toothbrush. I use my watch for surfing… and with the wipeout a lot of sand is swirled, too. (usually I wipeout more than I surf…)

freeheeler

@isazi
really? but the sensor sits so close to the holes… I suspect that I reached it more than once with the soft tips of the brush

EDIT:
here’s to imagine how soft my watch cleaning brush is

isazi

@freeheeler meaning I don’t push the bristles inside forcefully, they probably reach inside a little bit though.

Egika

@freeheeler official statement will always be: “do never put anything into the holes”
And recommending to do so is maybe not the best idea.
Even if your toothbrush is the softest on earth…

So let’s keep it a “don’t reach inside with anything”, you have no idea what people do…

(btw: I have also used a toothbrush to clean the S7 holes)

Pavlas

@egika @isazi @freeheeler Ok, thank you guys!

freeheeler

@egika
…like: scratch the dirt off the sensor with a rusty needle…
agreed: don’t reach inside!

actually soaking and rinsing should be sufficient