On Sun, 29 Apr 2007 22:36:55 GMT, Dallas
wrote:



But, that doesn't explain why none of the electronic calculators agree with
the 1000' pressure altitude on the chart.

Since moisture content of the air has a significant effect on the
calculation and I have never seen a specification for relative
humidity as part of the "standard day" it would seem that everyone is
free to pick their own value which would cause different results.