The wombat rule of thumb is 1"/1000' cheers Baron Carter
-----Original Message----- From: Pat Naughtin [mailto:[EMAIL PROTECTED] Sent: Friday, 18 July, 2003 03:31 To: U.S. Metric Association Subject: [USMA:26409] Air pressure Dear All, Is it a fair 'rule of thumb' assumption that air pressure decreases, from ground level to (say) 2000 metres, at a rate of 10 pascals per metre (Pa/m)* If this were true, then each decrease of 1 kilopascal would correspond to a height reduction of 100 metres. It seems to me that this might be an easy 'rule of thumb' to remember. *That's 1 mbar per 10 m for users of older methods. Cheers, Pat Naughtin LCAMS Geelong, Australia --
