Barometer and Altimeter on PRT 70, Help needed pls!

Thread: Barometer and Altimeter on PRT 70, Help needed pls!

Results 1 to 9 of 9
  1. #1
    Member
    Join Date
    Jul 2010
    Posts
    10

    Barometer and Altimeter on PRT 70, Help needed pls!

    Hi there,
    Recently found this site and have been trawling though it. Seems to have a lot of great stuff on it.

    Just the other day i bought a Pro Trek PRT70, my first one, i have a few G shocks but got this on sale and have always wanted one with altimeter and barometer function. My query is this, both the altimeter and the barometer seem to be all over the place, At the same geographic location the altimeter varies 100m or more. I keep resetting it but within a few hours it is out again. The same seems to happen with the barometer.

    I don't know if any one has this watch but it also has a barometer graph on it, which takes readings every 2 hours for the last 18 hours, this graph is meant to show the barometric readings but mine seems to stray all over the place. And I have several points on the graph with missed readings. The watch is notably better if I take it off my wrist and leave it on the side but its meant to be a watch not a desk top display. I don't do anything abnormal with it just walk around the house etc.

    Any help would be most appreciated. Thanks.

  2. #2
    Member cal..45's Avatar
    Join Date
    Jun 2006
    Location
    CMOWE (Central Madhouse Of Western Europe)
    Posts
    8,512

    Re: Barometer and Altimeter on PRT 70, Help needed pls!

    welcome jimmy

    the altimeter and barometer are directly related which means if airpressure rises, the altimeter drops. if airpressure drops, the altimeter rises.

    1 mbar(hpa) is equal to about 8.3 meters in altitude. so lets assume one lives at the ocean (sea level = zero meters) and the airpressure drops 10mbar, the altitude will be about 85 meters above sea level. contrary if the the airpressure rises by 10mbar, altitude will be 85meters below sea-level.

    this is what you encounter right now with your PRG-70 and it will always be that way, since airpressure is only very seldom constant over a longer period.

    unfortunately no casio ABC watch is equiped with a so-called altimeter lock, that would either mostly prevent or completely avoid those altitude drifts, no matter what the barometer is doing.

    if you check your local pro weatherstation (if you have one nearby) you will find that your barometer never shows the same value as the weatherstation. this is because weatherstations usually display the airpressure at sealevel, while your watch actually measures the current pressure at your altitude.

    lets assume you live 100meters above sea level, so your barometer will always display about 12 mbar less than the pro. (100:8.3=12).

    all this can be quite confusing, especially for someone who is new to the ABC watch world. but you will learn to handle this and if you feel that casio ABC's are not accurate enough, there are always great alternatives from other brands.


    cheers
    We are 12.6 %

  3. #3
    Member
    Join Date
    Jul 2010
    Posts
    10

    Re: Barometer and Altimeter on PRT 70, Help needed pls!

    Hey cal..45, thanks very much for the detailed explanation, that makes a lot of sense. I see why it drifts so much now.

    I actually live at sea level (well 10m above) but work in a location that is about 50m, so i can see why there is a difference in barometer readings from these two locations.

    The other thing I was worried about was the missing points on the barometer graph but I have figured out that the graph only shows a range of 7 millibars for readings so if two readings are more than 7 millibars out, which happens when altitude changes, one of these will not be shown on the graph.

    Anyway, thanks again for getting back to me, i really appreciate it. I'm happy with my watch and the abc functions are cool but i don't need to rely on them, so its ok.

    you say that there are more accurate alternatives from other brands, could you name a few so i could check them out. Cheers

  4. Remove Advertisements
    WatchUSeek.com
    Advertisements
     

  5. #4
    Member cal..45's Avatar
    Join Date
    Jun 2006
    Location
    CMOWE (Central Madhouse Of Western Europe)
    Posts
    8,512

    Re: Barometer and Altimeter on PRT 70, Help needed pls!

    Quote Originally Posted by jimmyc View Post
    you say that there are more accurate alternatives from other brands, could you name a few so i could check them out. Cheers
    - personally i swear on my traileader jet made by tech4o.

    - the timex WS4 is also a very good and reliable ABC.

    - cheap in price but not cheap in functions is the weathermaster VII

    - a lot of people swear on the suunto core, but i have no personal experience with this brand.

    anyway, here are a few links:

    http://store.tech4o.com/category/345...utmk=225267738

    http://www.timex.com/Timex-WS4/dp/B002C13PVQ

    http://www.proidee.co.uk/shop/SID_k3...suche_variabel

    http://suunto.com/en/Products/Outdoo...ore-All-Black/


    cheers
    We are 12.6 %

  6. #5
    Inactive
    Join Date
    Feb 2010
    Posts
    856

    Re: Barometer and Altimeter on PRT 70, Help needed pls!

    Quote Originally Posted by jimmyc View Post
    The watch is notably better if I take it off my wrist and leave it on the side but its meant to be a watch not a desk top display
    Also, the sensors are affected by temperature changes. The newer Casios (some Riseman 9200 editions, but maybe not all, and the PRW-2000 and PRW-5000, and maybe a couple more) have a built-in compensation for this.

    Is this your watch? http://www.google.dk/imgres?imgurl=h...26tbs%3Disch:1

    Looks really, really great I'd like to get such one some day...
    Last edited by ThomAsio; July 15th, 2010 at 11:00.

  7. #6
    Inactive
    Join Date
    Feb 2010
    Posts
    856

    Re: Barometer and Altimeter on PRT 70, Help needed pls!

    Quote Originally Posted by jimmyc View Post
    Just the other day i bought a Pro Trek PRT70
    May I ask where you bought it? I've found it on two webshops, but one got techy problems, when I try to order (for checking shipping costs), and the other is in Hungarian - Google can translate it, buy not so well, and I like to check the delivery and warranty policies first

    Thanks

  8. #7
    Member
    Join Date
    Jul 2010
    Posts
    10

    Re: Barometer and Altimeter on PRT 70, Help needed pls!

    Hey ThomAsio, yeah that's the model i have, I have the grey one with the resin strap not the material strap one. I got mine from a local Casio dealer in the UK (Plymouth) it doesn't have a webpage or anything I'm afraid. I guess it must be quite an old model as he was selling it off nearly half price (£65). I searched for it on the internet after i bought it and couldn't really find it anywhere. Its a good watch, and I'm pretty happy with it, just wish it was a little more accurate.

  9. #8
    Inactive
    Join Date
    Feb 2010
    Posts
    856

    Re: Barometer and Altimeter on PRT 70, Help needed pls!

    Regarding accuracy, this might be an option: https://forums.watchuseek.com/showthread.php?t=83153

  10. #9
    Member
    Join Date
    Jul 2010
    Posts
    10

    Re: Barometer and Altimeter on PRT 70, Help needed pls!

    Quote Originally Posted by ThomAsio View Post
    Regarding accuracy, this might be an option: https://forums.watchuseek.com/showthread.php?t=83153
    Thanks man, i will check it out when i get some time, cheers

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

    Posting Permissions

    • You may not post new threads
    • You may not post replies
    • You may not post attachments
    • You may not edit your posts
    •