why

Discussion in 'Earth Science' started by sculptor, Apr 2, 2021.

  1. sculptor Valued Senior Member

    Messages:
    8,322
    why
    do some people call a millibar a hectopascal?

    and
    which word do you use?


    ...........................................
    (I ain't completely confused yet----but I am working on it.)
     
  2. Google AdSense Guest Advertisement



    to hide all adverts.
  3. RainbowSingularity Valued Senior Member

    Messages:
    7,371
    milli is old system ?
    hecto is new system ?

    https://en.wikipedia.org/wiki/Bar_(unit)

    https://en.wikipedia.org/wiki/Pascal_(unit)

     
  4. Google AdSense Guest Advertisement



    to hide all adverts.
  5. exchemist Valued Senior Member

    Messages:
    11,478
    The Pascal is the SI unit. The bar (1 bar = 10⁵ Pascals) is a non-SI metric unit.

    So yes, 1 millibar = 100 Pascals.

    I tend to think in terms of bar, but I'm old-fashioned. If you are taking a school examination in Europe, you need to use SI units or you lose marks.
     
  6. Google AdSense Guest Advertisement



    to hide all adverts.
  7. sculptor Valued Senior Member

    Messages:
    8,322
    I prefer millibars----(it's more comfortable to say than hectopascal)
    and it's on my barometer
    as is cm/hg
    meanwhile the local meteorologists use inches of mercury
     
  8. James R Just this guy, you know? Staff Member

    Messages:
    37,566
    I guess the motivation for measuring pressure in bars is that the air pressure at sea level hovers near 1 bar.

    For more accuracy, we can use millibars, which means weather reporters can talk about "pressure of 1013 millibars" rather than "1.013 bars".

    But the standard SI unit of pressure is the Pascal, and 1 millibar is the same as 1 hectopascal. "Hecto-" is a standard SI prefix that means "one hundred". So, "1013 millibars" is the same as "1013 hecto-Pascals".
     

Share This Page