Casio Pathfinder Men's Watch

[Shardik]

New Holiday Gadget:
http://www.casio.com/products/Timepiece/Pathfinder/PAW1100T-7V/
Since my Garmin Legend HcX doesn't have a barometric altimeter, I figured having a watch/altimeter, would be a good idea.Really cool to predict the rain, using the graph on the barometric reading.
Well.....
Used for a few days and under one of the most deadly hiking conditions imaginable......
BOXING DAY at the Shopping Malls
(local crappy weather conditions made this horrible event happen)

Picked it up locally for about 150.00CAN at our local Costco just before xmas, for one of those surprise presents from the wife to me.

Pros: Seems tough and easy to set up.Batteries not required (solar) and sets its own time by radio reception.
Display easy to read .Backlight functions well.Compass,Altimeter,Thermometer and Barometer and regular time settings.

Cons:Altimeter requires constant setting.(More on this later)Unit a bit too large ,heavy leading to some wrist discomfort and band movenent.Alarm volume a tad low for my usage.

The Altimeter : which is the big reason for this watch.

Maybe I was just unlucky with the days that I was using this watch, but for the past few days we have been through a roller coaster of barometric changes.Because of this the, Altitude readings were wacky, even after setting at a known level in the morning.I brought along my Garmin (without barometric pressure capability).Using ranges 0-500 meters the Garmin performed well, wheras the Casio was a disaster, with readings off by as much as 350 meters.
I assume that if I kept adjusting the Casio at known elevations,the readings would have been more accurate.But really ,this is a pain and may lead me to question the accuracy at time of need.

IMHO bottom line, nice toy, but it is going back. Hand discomfort and unrealistic for my needs.

I would not recommend this item to a friend.

Best of the season to you all
Shardik

 

[Chip]

I had the HighGear Summit for about a year and would give it a similar review. I sold it on ebay for about half my cost. I do miss the temp and barometer, which I found more useful than the (untrustable) altitude readings.

 

[Shardik]

I do miss the temp and barometer, which I found more useful than the (untrustable) altitude readings.

Thanks Chip,seems that you had the same experiance. Will keep this in mind when shopping around.

An interesting quote from your link:

"Making bail after every BASE jump can really burn a hole in your pocket, so consider the value-minded HIGH GEAR SUMMIT."

I guess he is more concerned about the cost , than his..... landing.

 

[Quietman]

I recently picked up a Highgear Altiforce altimeter watch on ebay for $30. This is a military version of the Highgear Alterra.
I haven't calibrated the altimeter for over a week and it is still accurate to within 10 feet. It was also accurate to within 50 feet after a flight from Boston to Charlotte, and very accurate on many area hikes. Overall I am very impressed with it. The Highgear Aerial is currently on clearance from Backcoutry.com for $37.50(from $135). Can't give any recommendations on this model, but I am happy with mine.

 

[MichaelJ]

I got the Pathfinder a few years ago at somebody's clearance sale for 50% off. Thought it was a great bargain, and in even weather it did work well on the trails in the Whites. The problem I had was that when the battery finally ran out, nobody could replace it, not even a jeweler. I needed to send it to Casio, which of course I never got around to doing. It's still sitting on my gear shelf.

 

[BlackBuffalo]

Thanks for the reviews. Been considering getting one of these gadget watches cause they have a built in altimeter/temp, etc.
I think I'll stick to a standard inexpensive watch till features like these are perfected.
DaveG.

 

[Chip]

I recently picked up a Highgear Altiforce altimeter watch on ebay for $30. This is a military version of the Highgear Altis.
I haven't calibrated the altimeter for over a week and it is still accurate to within 10 feet. It was also accurate to within 50 feet after a flight from Boston to Charlotte, and very accurate on many area hikes. Overall I am very impressed with it.

Good to hear. I see your's has the Swiss altimeter sensor. I think that's where mine went wrong. $30 for that watch was a great deal.

 

[DougPaul]

All barometric altimeters require frequent calibration (~once a day or more often) if they are to have any meaningful accuracy. If the calibration lasts a longer time, it is just luck that the atmospheric pressure has stayed relatively constant (or drifted back to the pressure at the time of calibration). The atmospheric pressure can change rapidly enough to significantly reduce the accuracy within an hour or less.

Yes, you need a quality sensor, but it still needs to be calibrated frequently to be useful for estimating the altitude. The altitude vs pressure calibration is also affected by the humidity and temperature profiles between the calibration altitude and time and the current altitude and time.

In contrast, a GPS altimeter can have a short-term error of 2-3 times the horizontal error, but is unaffected by the atmosphere and never needs to be calibrated. GPSes which include a barometric altimeter can use the GPS altitude to continuously calibrate the barometric altitude and are the best of both worlds.

Doug

 

[Quietman]

I corrected my 1st post. The Altiforce is almost identical to the Alterra(not the Altis). The Alterra and the Aerial differ only in that there isn't a compass on the Aerial.

I agree with all that DougPaul said. I had checked my watch daily and it had stayed accurate, but would definitely re-calibrate it before a trip. The watch has a nice feature of having altitude presets(like my home's altitude) so that I can calibrate it very easily. It won't tell me where I am, but at least I have a good idea of what the altitude is.

Mine was a great deal, the guy I got it from put a minimum bid of $50 on the next one he listed, and it sold for $75.

 

[Shardik]

Please clarify

In contrast, a GPS altimeter can have a short-term error of 2-3 times the horizontal error, but is unaffected by the atmosphere and never needs to be calibrated. GPSes which include a barometric altimeter can use the GPS altitude to continuously calibrate the barometric altitude and are the best of both worlds.
Doug

Hi Doug,

Please explain the 2-3 times horizontal error using a GPS altimeter.
(I expect that the accuracy wouldn't be perfect,but how off could it be ?)

Do GPS's with barometric altimeters automatically calibrate off of the GPS signal and override the barometric system ?

Thanks,
Dave

 

[DougPaul]

Hi Doug,

Please explain the 2-3 times horizontal error using a GPS altimeter.
(I expect that the accuracy wouldn't be perfect,but how off could it be ?)

GPS has a nominal horizontal accuracy of 10 meters (ie 95% probability of reading within 10 meters of the actual location) under good receiving conditions. The vertical accuracy is ~20 meters.

Do GPS's with barometric altimeters automatically calibrate off of the GPS signal and override the barometric system ?

Don't know about all GPSes, but this is what Garmin does on their GPSes with barometric altitude sensors*:
The system reads out the barometric altitude, not the GPS altitude**. There are multiple user-selectable calibration modes, including manual from known altitude or reference pressure, manual from the GPS, and automatic. The automatic mode slowly but continuously calibrates the barometric altimeter and requires an hour or more to become accurate. GPS altitude errors vary on a short time scale, barometric on a long time scale. The net effect is that the slow calibration averages out the GPS errors. The combination is more accurate than either alone. (If the calibration of the barometric sensor was continuously overridden by the GPS, then you would just be getting the GPS altitude.)

This automatic calibration scheme works out fairly well in normal applications, but when you fly in a commercial aircraft the cabin pressure altitude is generally held below 8K ft even when the true altitude is >20K ft. Under these conditions the barometric sensor reads the cabin altitude while the GPS reads the true altitude. (The auto-calibration stops under this condition.)

* GPSes without barometric sensors simply use GPS altitude all the time.

** You can read out the GPS altitude from the menus on the satellite page.

Doug

 

[Shardik]

Doug,

I appreciate your help with the detailed explanation ,and it has restored my confidence in Barometric GPS's.

Thank You,


Quietman,

Still during the trip, it would need to be calibrated on the fly,especially when entering different weather systems.This could get a bit dicey, at times.
With limited visibility, these are the times that it may be most needed.

IMHO,automatic settings would be better during a hike or trek.
Not always easy to find an altitude indicator, especially in winter or in unfamiliar territory....or even remember , that last time calibrated.


Dave

 

[JoeCedar]

Winter Altimeter Errors

I noticed that my Suunto altimeter seemed to always read several hundred feet high when reaching summits in the winter, although it varied as expected in summer (sometimes close, sometimes not), depending of course on the pressure change during the hike. I thought it needed calibration until I looked up the subject online. I also have and use a Garmin GPSMAP 76Cx.

The calculation built into barometric altimeters to convert pressure into altitude is based on the ICAO Standard Atmosphere:

*The air is a perfectly dry gas
*The barometric pressure is 1013.2 hPa (29.92 inches of mercury (inHg))
*The temperature is 15°C
*The rate of temperature fall with height is 1.98°C per 1000 feet up to the height at which the temperature becomes -56.5°C and then remains constant.

The problem in cold climates is that the outside air is so much different from the ICAO standard 15 C, and this causes significant error in the altitude reading when the altitude is set at one point (the "airport") and then one climbs a mountain (or the airplane in flight). See this article for more information.

Here is just one example from this article, converted to be relevant to winter climbing:

You set your altimeter at the trailhead at ambient temperature of -10 C (14 F) at an elevation of 2000 ft, then climb a 3000 foot mountain on a day when the atmospheric pressure is stable, i.e., when you return to the trailhead later the reading is identical. On the summit your altimeter will read 5290 ft, i.e., 290 ft high. With lower temperature, the error is even greater. In summer, when the Standard Atmosphere accurately represents the actual atmospheric conditions, you can often get the correct altitude of a summit (or close, if pressure is stable).

So don't be too quick to blame the altimeter for inaccuracy in the winter. The GPS, of course, doesn't have this problem, but the its calculation uses other assumptions to get the value you see on the screen.

If you are interested in learning more on this topic, here is a follow-up article by the author.

 

[DougPaul]

The calculation built into barometric altimeters to convert pressure into altitude is based on the ICAO Standard Atmosphere:

This article refers to aircraft altimeters, not hiking altimeters. Aircraft altimeters have the requirement that all should have the same environmental error to provide vertical separation between aircraft. Hiking altimeters have no such requirements and I am not aware of any requirements that they must follow any particular standard. (This doesn't mean that hiking altimeters do not try to meet the aircraft standards, just that there are no regulations requiring them to do so.)

FWIW, I have some humidity and temperature corrections to be applied to my Thrommen* mechanical altimeter. Don't recall where I got them.

* Thrommens were the standard in hiking altimeters. Mine has a rated accuracy of +-10 meters.

Doug

 

[MichaelJ]

This automatic calibration scheme works out fairly well in normal applications, but when you fly in a commercial aircraft...

Just as an interesting aside, the use of a GPS on a commercial flight is expressly forbidden by a number of airlines, even at cruise when other electronics are allowed. You can see a fairly current list here.