One (standard) atmosphere is 101.325 kPa. However, properties for many chemicals are specified at 1 bar (100 kPa) rather than 1 atm. There is also a 'technical atmosphere" 98.0665 kPa (based on kilogram-force), which is now deprecated and rarely used..
--- On Sun, 9/4/11, Michael Payne <[email protected]> wrote: From: Michael Payne <[email protected]> Subject: [USMA:51064] Re: planes collide To: "U.S. Metric Association" <[email protected]> Date: Sunday, September 4, 2011, 6:58 AM I believe one atmosphere is still 100 kPa, the 1013,25 comes from the International Standard Atmosphere. Commonly referred to as the ISA it's what manufacturers use to calibrate instruments and what aircraft makers use to calibrate the performance of aircraft. In the aviation world we constantly refer to the temperature being below or above ISA, the lapse rate is fixed under ISA as 1.98 C up to 36090 (11000 m) where it's supposed to be constant. Obviously in the real world it changes which has an affect on performance. Mike Payne On 03/09/2011, at 13:57 , G. Stanley Doore wrote: The 1013.25 mbar (101.325 kPa) pressure for altimeter settings is NOT "arbitrary" as Kilopascal & Wiki write. The standard altimeter setting for worldwide altimeter settings was determined from the mean surface pressure level. Stan Doore On Sep 3, 2011 11:36 AM, "Michael Payne" <[email protected]> wrote:
