Altimeter Calibration Height

You snipped part of Jose's message:

"Also, even if the static port and the instrument themselves are separated
in altitude, it would be the instrument altitude's pressure that is sensed,
since the "column of air" is connected, and ends at the instrument."

In other words, an altimeter indicates altitude at the level of the
instrument itself.

No. Correctly it would be "In other words, an altimeter =senses=
=pressure= at the level of the instrument itself."

Sensing pressure and indicating altitude are two different things.

Jose
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"Jose" wrote in message
t...

No. Correctly it would be "In other words, an altimeter =senses=
=pressure= at the level of the instrument itself."

Sensing pressure and indicating altitude are two different things.


An altimeter senses pressure in order to indicate altitude.

An altimeter senses pressure in order to indicate altitude.

Now we're getting somewhere. The pressure is sensed based on the laws
of physics. The altitude is indicated based on calibration and Kollsman
setting.

Jose
--
Get high on gasoline: fly an airplane.
for Email, make the obvious change in the address.

"Jose" wrote in message
t...
An altimeter senses pressure in order to indicate altitude.

Now we're getting somewhere. The pressure is sensed based on the laws of
physics. The altitude is indicated based on calibration and Kollsman
setting.


Maybe I'm missing something here, but would it simplify to say:

That if you mount an altimeter at the 100' level of a 200' tower,
equiped it with a static tube 100' long,
that the altimeter will read the same regardless if end of the tube,
is stationed at the top or bottom of the tower.

?????

if you mount an altimeter at the 100' level of a 200' tower,
equiped it with a static tube 100' long,
that the altimeter will read the same regardless if end of the tube,
is stationed at the top or bottom of the tower.

That is a mostly true statement. Conditions inside the tube could
differ from ambient conditions, this would engender a teeny (but real)
difference in readings.

Jose
--
Get high on gasoline: fly an airplane.
for Email, make the obvious change in the address.

"Jose" wrote in message
. ..
if you mount an altimeter at the 100' level of a 200' tower,
equiped it with a static tube 100' long,
that the altimeter will read the same regardless if end of the tube,
is stationed at the top or bottom of the tower.

That is a mostly true statement. Conditions inside the tube could differ
from ambient conditions, this would engender a teeny (but real) difference
in readings.

Jose

You mean like pressure loss of the long length or something?

if you mount an altimeter at the 100' level of a 200' tower,
equiped it with a static tube 100' long,
that the altimeter will read the same regardless if end of the tube,
is stationed at the top or bottom of the tower.

That is a mostly true statement. Conditions inside the tube could
differ
from ambient conditions, this would engender a teeny (but real)
difference
in readings.

Jose

You mean like pressure loss of the long length or something?


Humidity or moisture content comes most readily to my mind.

Peter

You mean like pressure loss of the long length or something?

The conditions inside the tube are different from the conditions outside
the tube. I expect they'd be very similar, but given a very long, very
insulated tube, which starts out with (say) dry air, followed by the
passage of a moist front, there would be a difference.

Jose
--
Get high on gasoline: fly an airplane.
for Email, make the obvious change in the address.

"Maxwell" wrote in message
...

Maybe I'm missing something here, but would it simplify to say:

That if you mount an altimeter at the 100' level of a 200' tower,
equiped it with a static tube 100' long,
that the altimeter will read the same regardless if end of the tube,
is stationed at the top or bottom of the tower.

?????


Why didn't I think of that?

Maxwell wrote:
"Jose" wrote in message
t...
An altimeter senses pressure in order to indicate altitude.
Now we're getting somewhere. The pressure is sensed based on the laws of
physics. The altitude is indicated based on calibration and Kollsman
setting.


Maybe I'm missing something here, but would it simplify to say:

That if you mount an altimeter at the 100' level of a 200' tower,
equiped it with a static tube 100' long,
that the altimeter will read the same regardless if end of the tube,
is stationed at the top or bottom of the tower.

Yes, that is correct. There might be a slight transient as you moved
the tube, but at steady state the location of the tube would not matter.

Matt