Tom,
You are noting the altimeter correction factor and
then applying it to the new altimeter setting, aren't
you?

If I get 29.90 from AWOS at Minden and then set it
into my altimeter and it reads 4800 feet, I must readjust
the setting to make it read field elevation (4720)
and then note the altimeter correction factor (- .1)
which I must apply to any new altimeter setting I get
in the air.
JJ

At 17:12 30 July 2007, 5z wrote:
On Jul 30, 7:21 am, John Sinclair
wrote:
I don't find this to be true, Andy. Altimeters need
to be re-set primarily when landing at a destination
1000's of miles away from the takeoff location.

We have an AWOS right on the airport, so I set the
mechanical and 302
to this shortly before takeoff. When I check the altimeter
after 4-6
hours, the change is typically 1-200' - and usually
puts me lower.
Really unsettling if I'm on a marginal glide and the
air looks stable
ahead.

-Tom