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Anonymous asked in Science & MathematicsWeather · 1 decade ago

Given barometric pressure in mm Hg and Temperature in K, how significant is a change in actual pressure?

I took a barometric reading to be 758 mm Hg at 69 F or 293.5 K. I want to convert this to pascals but most mm Hg conversions are done with temperature at 32 F or 273 K. Is this temperature difference significant enough to alter the converted pressure in pascals?

1 Answer

  • 1 decade ago
    Favorite Answer

    My calculator gives me 101,058 Pascal or, as the ISA requests it: 1010.58 hPa.

    I fail to understand why you involve the temperature that has nothing to do with the pressure in a not contained atmosphere. Furthermore, I don't understand you 32 F (0 C). If you want to use a standard temperature, the ISA gives 15 C (59 F) as the average temperature on earth at sea level. That, together with 1013.25 hPa as pressure at sea level and 0.65 C per 100 meters (3F per 1,000 ft) as lapse rate, is the International Standard Atmosphere on which all instruments, especially aviation ones, are calibrated for. I hope it helps.

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