altimeter advice

[DougPaul]

I have both a Thrommen altimeter and a recent model GPS (Garmin 60CSx) with a GPS-calibrated barometric altimeter. Both work well. The GPS barometric altitude is rated +-10ft and the Thrommen is rated +-10m (+-33ft). Both these accuracies assume proper calibration.

The Thrommen has to be manually calibrated at a known point and is subject to drift due to barometric pressure changes while the automatic calibration of the GPS-calibrated barometric altimeter automatically compensates for pressure changes. With appropriate care, either is perfectly adequate for hiking navigation.

BTW, the accuracy of a direct-from-the GPS altitude (ie one without the barometric sensor) is worse than either of the above.

I used to carry my Thrommen, now I just carry the GPS since it gives me altitude and more. (And I don't have to worry about calibration...) There are times when I ignore the position given by the GPS and look only at the altitude. Also some of the earlier GPSes (which are more likely to lose lock under the trees) still give a good barometric altitude when they lose lock.

Doug

 

[DougPaul]

A quick scan of the "what's in your pack" threads does not reveal the word altimeter. It could be that the GPS serves that function. If one assumes that one goes hiking in the Whites, stays on trail, and doesn't press on in deteriorating conditions, is there a situation where an altimeter (alone, not in a GPS) is genuinely helpful? The only one I can think of is it might give you a pretty good hint as to how far you have to go to a trail junction, or other landmark identifiable by a contour interval.

If you stay on the trails, an altimeter is rarely needed, but it can tell you where you are on the trail. (Or at least give you a small number of alternatives.)

If you go off trail, knowing which contour you are on can be very helpful. I have done such things as follow a gully down to some altitude and then traverse out of it. Or you can go to the altitude of your objective and then traverse until you get there.

Water depth can be used similarly in marine navigation. Some of the instruction manuals say it tells you where you are not. The same logic can be applied to altitude.

Doug

 

[bikehikeskifish]

Somehow, I knew Doug would get involved here

I certainly understand the marine navigation analogy. Between channel markers ("on trail") in a busy harbor it is relatively safe to assume clear passage, unless you draft a lot more than average, or it is a large minus tide (and it is low).

Perhaps Bryan (OP) would be kind enough to share the intended usage for this purchase?

Tim

 

[bryan]

sorry, i am online sporatically. thanks for all the input and ideas.
as far as my intent, i am looking to venture out more off trail than i have in the past and was hoping to have some tools at my disposal to keep track of myself. i was hoping to avoid relying too much on gps and instead learn map and compass with the added benefit of an altimeter. bushwacks in new england for now.
thanks.

bryan

 

[DrewKnight]

Suunto X9 Altimeter-Watch

Certainly not as sophisticated as a stand-alone altimeter, but I have been very satisfied with my Suunto altimeter-watch. It works well with a simple baseline calibration at the trailhead (assuming you have a good altitude reading), and has a lot of nice digital features -- rate of climb/descent, alternate use as a barometer, OK compass, and good heart-rate monitor functions.

On the negative side, the backlighting is very weak, and the thermometer is silly -- if you're wearing the watch, it doesn't have much chance of giving you an accurate temperature reading.

There are several brands that offer similar feature-function packages, and I have seen similar units on Campmor.com for well under $200.

 

[Pig Pen]

High Gear Altitech

I use a High Gear Altitech. I bought it because of the carabiner clip that it uses to attach to a back pack. It's very handy. It works great about 90% of the time and 95% of the features work. Let me tell you about the other 10 and 5 percents.

10% of the time it doesn't work:
In my opinion these altimeters have a water resistance issue. When I bushwhack in wet conditions the altimeter occasionally goes crazy, giving wildly inaccurate altitude readings. The problem first becomes evident when I start seeing 50 to 100 foot jumps in the readings and gradually gets worse occasionally showing readings that are thousands of feet off.

They also don't work in very cold weather. Below 5 degrees F, the display gets very dim and will become unreadable at about -10. The spec sheet actually states this so it's not really a malfunction but it's something that you should know.

5% of the features don't work:
The accumulated altitude feature over-estimates altitude gain by 20%.

I called them up about these issues and they gave me a replacement at half price. The replacement did the same thing.

I'm not trying to bad mouth the product. I'm just giving an honest assessment of my experience.