Calibrating the Riseman

Thread: Calibrating the Riseman

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  1. #1
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    Calibrating the Riseman

    How often does everyone have to calibrate the barometric pressures on the GW9200 Riseman? I find that mine will be very accurate for a few days, and all of a sudden it will be off. I know it is affected by temperature, but at times it just seems to get off track for no reason. Any help would be appreciated. Thank you.
    AUSTIN


    GW9200-1 Riseman
    GW9000A-1 Mudman
    GW5600J-1
    GW700BDJ

  2. #2
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    Re: Calibrating the Riseman

    I never calibrate the barometric pressure on my Riseman. The air pressure have probably been stable at your place for a few days, and then changed. At sea level the normal pressure is 1013 hPa (29,92 inHg), and when it is higher it is high pressure and lower is low pressure. The Riseman shows the absolute air pressure were you are located and it changes constantly.

    In weather prognoses there are often air pressure prognoses and they show air pressure relative to sea level. Example: If it shows that the relative air pressure is 1013 hPa at a place located at 1000 m (3280 ft) the absolute pressure at that place is 905 hPa (26,73 inHg) but still normal air pressure (neither low nor high air pressure).

    Hope this helped.

  3. #3
    Member Jeff_C's Avatar
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    Re: Calibrating the Riseman

    The barometer on my riseman is pretty accurate. The Alti is not quite as good. There has been lots of good discussion on pressure and ABC watches on the Digital / ABC forum and the Suunto forum if interested.

    Really for practical field use, the most important thing is not neciessarily the pressure at any time, but the pressure TREND... is it rising or falling as each has specific impacts on the weather.
    Suunto... Replacing Luck!



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  5. #4
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    Question Re: Calibrating the Riseman

    Thanks for the information. I drove up a sharp incline of about 400 feet today on the intestate and the pressure dropped from 30.05 to 29.55 as I got tot he top of the hill. I double checked the pressure both on the internet and my GPS and the pressure never changed, but my watch showed a dramatic change. I calibrated it, and later on I experienced another sharp/dramatic change in elevation with the same results. Is this normal?
    Last edited by Austin1983; December 25th, 2008 at 21:19.
    AUSTIN


    GW9200-1 Riseman
    GW9000A-1 Mudman
    GW5600J-1
    GW700BDJ

  6. #5
    Member WhtShadow's Avatar
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    Re: Calibrating the Riseman

    Air pressure changes with altitude, that is how the altimeter works. Pick a pressure and set it, then set tha altitude. The pressure should track pretty good when at home. Then you just need to reset the altitude when you are going out.

  7. #6
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    Re: Calibrating the Riseman

    Quote Originally Posted by WhtShadow View Post
    Air pressure changes with altitude, that is how the altimeter works. Pick a pressure and set it, then set tha altitude. The pressure should track pretty good when at home. Then you just need to reset the altitude when you are going out.
    Thanks, the pressure tracks very well at home, or in an area with a steady elevation. The rapid elevation changes do seem to mess with the pressure readings on the watch. My GPS also noted a drop in the pressure, but when I turned it off and back on it went back to the original and correct pressure. The watch never balanced itself back out.
    AUSTIN


    GW9200-1 Riseman
    GW9000A-1 Mudman
    GW5600J-1
    GW700BDJ

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