New Suunto Core owner – Help please.

[Stephen Murphy]

I have surfed for the answer to my question but have not had much luck, so hope someone here can help. I recently purchased this watch as the concensus was the altimiter was better than the one on my Pathfinder 1300. I just took my first day hike with it where the starting and ending altitude was known – about a 1,200' vertical change based on USGS topo maps. I set the elevation at the base, but, when I reached the top, the reading showed only about 1,000' change. I reset the altitude at the top ( there was a marker confirming elevation)and again the watch only registered about 1,000' change at the trailhead. It was a calm, sunny day so I do not think barometric pressure drops due to the weather was the cause, but I could be wrong about this.

I really like my Pathfinder 1300 and lived with the fact that altitude readings were +-100'. Am I expecting to much from the Suunto, or am I just using it wrong?

[Bruce Tolley]

I own a very old Suunto Vector.

You might try
1) Calibrating the Suunto versus a known good* reference, GPS or USGS map.
2) at point A take a measurement with the Suunto and with the reference device
3) at point B, take a measurement with the Suunto and with the reference device
Do not rely on the change in altitude algorithm of the Sunto. Look at how close the measurements are in 2) and 3) above between your watch and the reference device.

I find that my Suunto us usually pretty accurate.

*Note than neither a reading from the USGS map or from a GPS is 100% error free.

[Stephen Murphy]

I have since confirmed through a number of sources that the vertical elevation change is almost exactly 1,200'. So my Suunto fell short by approx 200' in both directions. Not sure how to put my hands on a reference device, but I do not think I need one as I know the actual measurement. I still do not know why my watch is off by so much. Anyone else have any ideas? I followed all the setup instructions. I am pretty disappointed right now.

[Ralph Burgess]

Stephen, I'm not really sure what you're asking for here. Obviously, Suunto altimeters are much more accurate than +/- 20%, or they would be lambasted in reviews. I have owned several, and they have all been accurate. You haven't explained where your complete certainty about the 1200' elevation change derives from, but if you're really that sure, then return the watch as defective.

[Stephen Murphy]

Iam certain the actual elevation change is correct. I am asking others if I have perhaps missed a step in calibration, if there is some settling in period, or something a Luddite like me may have overlooked in its operation or setup. It may be defective, but did not want to give up on it too quickly. I plan to hike again with it this weekend on the samr trail. I will also be bringing my Pathfinder, a Garmin Oregon 450 and whatever altimeter app I can find for my iphone – this could lead to total confusion but hopefully either 3 will agree and one will not, all will agree and I will have no further concern, or chaos will ensue.

In the meantime I will happily accept whatever constructive advice this forum might offer.

[Ralph Burgess]

The change in elevation with pressure is not something that can be adjusted by the user, so that's not something that you could have messed up. It's based on standard atmospheric conditions, so it will sometimes be off slightly, but any variation should be an order of magnitude smaller than 20%.

Given that you checked it both up and down the climb, I think you've ruled out the possibility of rapid concurrent change in ambient pressure.

Using a different climb with independently established elevation change would be better than going back to the same place. I think either your 1200' reference elevations are wrong, or the watch is miscalibrated. Checking against other instruments is sensible – can you borrow another Core to compare? That would be a conclusive way to check if it's miscalibrated, and would be obvious strong grounds to cite for returning it as defective.

[Ralph Burgess]

And once again,

"I am certain the actual elevation change is correct."

How?

You want help on finding the source of error – this is an obvious one, but you don't want to discuss it.

[Todd T]

I agree with others that it might be defective, but I'll just say this: My Suunto Core takes some time to equilibrate sometimes, especially if it's windy. Don't just read the elevation when you step on the peak, give it 5 minutes or so and see if it creeps on up toward the known elevation.

Also, mine is extremely erratic when it's on my sweaty wrist. It works just fine if I strap it on my hip belt while I hike instead of wearing it. (The erratic behavior is temporal–if I take the watch off at any time and wait a while, it eventually shows the correct elevation.)

Mind you, the erratic-on-sweat behavior is arguably a defect as well; I just thought I'd share my experience.

[Rick M]

del

[Ralph Burgess]

"The barometer measurement is not taken continuously, but every 2-5min…"

Suuntos sense pressure constantly, there should not be more than a few seconds delay in displaying altitude change if you're climbing quickly – and on my Suunto, there's not.

I think you may be thinking about the logging function, which permits you to RECORD the altitude/pressure periodicially, for a graphical display of the history. But the regular real-time altimeter display is pretty-much continuous.

Large amounts of moisture… now that's a possible source of problems, I guess. But I sweat way more than average (albeit perhaps not from my wrists), and I've never had a problem with that on several Suuntos.

[Stephen Murphy]

I am not reticent about discussing my source for elevation data, I simply see no need to waste time on this, but suffice to say this is a well travelled trail for which online trip reports by numerous hikers consistently record the same approximate data; it is also consistent with the official published trail map which lists both distance and elevation change for each trail; and finally is consistent with the relevant USGS topo maps. So lets accept the data is within acceptable tolerance and the altimeter readings do not jive.

I will take it on a couple of after work hikes this week – elevations are also well known where I hike after work. I will also try it strapped to my pack to see if my sweaty self is the culprit.

I will also pay attention to letting it"settle in". It is possible I did not give it enough time for this todat, either at the top or bottom. Always hoping for instant gratification I guess.

[Ralph Burgess]

Dumb thing, but to rule it out, put in a new battery? You can pick up reputably branded CR2032's cheaply at Home Depot.

[Bruce Tolley]

"..the altimeter readings do not jive."

I wrote what I did earlier in this thread because from the original post, it seemed that you were looking at the Suunto's altitude difference function, not actually taking specific altitude readings.

It would seem that if you were able to carry a GPS and calibrate the watch against the GPS, then ascend 1000 feet and compare the two altitude measurements and find a 200 foot difference, then you have a malfunctioning device. You could also sync the Suunto with your Casio at the beginning of an ascent….

If the altitude difference function is entering the error, then you have a different problem but still a malfunctioning device, but possibly fixable by upgrading the software.

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