units of measurement on altimeters

On Sun, 7 Mar 2004 16:18:10 +0000 (UTC), "Jukka K. Korpela"
wrote:

(Pat Norton) wrote:

Do all commercial aircraft that fly in and out of North America have
dual unit altimeters (hPa and inHg)?

I don't know about that, but as regards to the metric system, I would
like to mention that using hPa is _not_ the recommended way. Although
the "h" prefix is formally part of the SI system, it's regarded as
unsuitable by many, including NIST.

In practice, using hPa means being just _nominally_ metric, i.e. using
actually millibars but under a different name. The odd thing is that
the correct kPa would be more practical.

Amen.
http://ourworld.compuserve.com/homep...d/hectopas.htm

This screwball unit is just a misguided effort to hang onto an
obsolete unit by cloaking it in a marginally SI name. It makes no
more sense than soils scientists measuring soil conductivity (or
whatever is the proper term for the quantity measured, I'm doing this
off the top of my head without checking the terminology used) in units
of "dS/m".

Can you figure out the ever-so-handy unit the soils scientists are so
desperately trying to salvage?

Gene Nygaard
http://ourworld.compuserve.com/homepages/Gene_Nygaard/

"Gene Nygaard" wrote in message
...
On Sun, 7 Mar 2004 16:18:10 +0000 (UTC), "Jukka K. Korpela"
wrote:

(Pat Norton) wrote:

Do all commercial aircraft that fly in and out of North America have
dual unit altimeters (hPa and inHg)?

I don't know about that, but as regards to the metric system, I would
like to mention that using hPa is _not_ the recommended way. Although
the "h" prefix is formally part of the SI system, it's regarded as
unsuitable by many, including NIST.

In practice, using hPa means being just _nominally_ metric, i.e. using
actually millibars but under a different name. The odd thing is that
the correct kPa would be more practical.

Amen.


What about the pieze = 1000 pascals?

On Sun, 7 Mar 2004 20:42:10 -0000, "S Green"
wrote:


"Gene Nygaard" wrote in message
.. .
On Sun, 7 Mar 2004 16:18:10 +0000 (UTC), "Jukka K. Korpela"
wrote:

(Pat Norton) wrote:

Do all commercial aircraft that fly in and out of North America have
dual unit altimeters (hPa and inHg)?

I don't know about that, but as regards to the metric system, I would
like to mention that using hPa is _not_ the recommended way. Although
the "h" prefix is formally part of the SI system, it's regarded as
unsuitable by many, including NIST.

In practice, using hPa means being just _nominally_ metric, i.e. using
actually millibars but under a different name. The odd thing is that
the correct kPa would be more practical.

Amen.


What about the pieze = 1000 pascals?

The International System of Units is a meter-kilogram-second system of
units.

That mts unit of pressure is no more SI than the cgs unit of pressure,
the barye equal to 0.1 Pa.

Note that bars are so obsolete that they never did fit into any of the
many different coherent systems of units--not only do they not fit in
SI or any other coherent meter-kilogram-second system, but they did
not fit in centimeter-gram-second systems and they did not fit in
meter-ton-second systems.

Gene Nygaard
http://ourworld.compuserve.com/homepages/Gene_Nygaard/

"S Green" writes:
What about the pieze = 1000 pascals?

http://www.unc.edu/~rowlett/units/dictP.html

pieze (pz)

a metric unit of pressure, part of the "metre-tonne-second" system
sometimes used by European engineers. The pieze is a pressure of
one sthene per square meter, or 1000 newtons per square meter,
or one kilopascal. [...]
The name of the unit comes from the Greek piezein, to press.
The unit, spelled pièze in French, is pronounced "pee-ezz" in English.

Interesting. I had never heard of a metre-tonne-second system
before. Where was it invented and in which fields was it used?

Markus

"Markus Kuhn" wrote in message
...
"S Green" writes:
What about the pieze = 1000 pascals?

http://www.unc.edu/~rowlett/units/dictP.html

pieze (pz)

a metric unit of pressure, part of the "metre-tonne-second" system
sometimes used by European engineers. The pieze is a pressure of
one sthene per square meter, or 1000 newtons per square meter,
or one kilopascal. [...]
The name of the unit comes from the Greek piezein, to press.
The unit, spelled pièze in French, is pronounced "pee-ezz" in English.

Interesting. I had never heard of a metre-tonne-second system
before. Where was it invented and in which fields was it used?

Markus

Well as I said our aircraft has the manifold pressure in pieze

ie 27 inches = 90 pieze approx