Temperature Change affecting pitch

[Farrell]

If I remember my college chemistry, warm air holds more water molecules
because it is at a higher energy state. That is, the air molecules are
moving more rapidly, and thus can suspend more water molecules. As
temperature drops, air molecule energy decreases and cannot suspend as many
water molecules.

Terry Farrell
Piano Tuning & Service
Tampa, Florida
mfarrel2@tampabay.rr.com

----- Original Message -----
From: "Richard Brekne" <richardb@c2i.net>
To: <pianotech@ptg.org>
Sent: Tuesday, March 28, 2000 4:11 PM
Subject: Re: Temperature Change affecting pitch


Er.... this is not correct ????..

Warmer air expands... true... but this simply makes more room for more
H2O to be contained by it. You never experienced a 90% RH day at 35 ¤
did you ??? Cold air "squeezes" humidity out and  RH goes down. Grin...
generally cus it rains or snows it out.

Course its more complicated really than this... Wind / Circulation comes
into play... etc.. But I cant see how raising temperature in itself is
going to lower humidity, unless there are absolutely no other
contributing factors. True enough.. in a closed sealed container.. with
a given RH and Temp, a raise in temp will lower RH simply because the
air is now "capable" of holding more H2O then before. But real climatic
conditions arent so simple.

In Bergen.. We get real low RH readings when the temperature drops.. and
in the summer.. It goes way up.



Newton Hunt wrote:

> Temperature and humidity are coupled together, raise temperature
> and humidity lowers and visa versa.  Warmer air expands and
> stretches the humidity as well.
>
> Your measurements need to accompany humidity readings as well to be
> truly interesting.
>
> Go back to the lab and reexperiement.
>
> Nice having fun toys isn't it?
>
>                 Newton

--
Richard Brekne
Associate PTG, N.P.T.F.
Bergen, Norway