Temperature Change affecting pitch

[Farrell]

That makes sense. I'm convinced.

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

----- Original Message -----
From: "Don" <drose@dlcwest.com>
To: <pianotech@ptg.org>
Sent: Wednesday, March 29, 2000 5:43 PM
Subject: Re: Temperature Change affecting pitch


> Hi Terry,
>
> The strings don't have much mass and metal contracts as it is cooled. It
> takes only a few seconds to test this. Put a piece of ice in a plastic bag
> and touch it to a freshy tuned unison. Leave it there for 30 seconds. Now
> listen or check with a VTD.
>
> The plate being much more massive takes longer to adjust. A phenominone
> know as thermal drag.
>
> At 04:43 PM 3/29/00 -0500, you wrote:
> >Now why would turning on the AC make a piano go sharp? The cooler temp.
> >would make the plate and case contract (albeit very slightly), thus
lowering
> >pitch, and the lower humidity (because any properly operating AC unit
will
> >remove water from the air, thus lowering relative humidity) would tend to
> >make the soundboard contract, again lowering the pitch. Why in the world
> >would it go sharp?
> >
> >Terry Farrell
>
> Regards,
> Don Rose, B.Mus., A.M.U.S., A.MUS., R.M.T., R.P.T.
> Tuner for the Saskatchewan Centre of the Arts
> drose@dlcwest.com
> http://donrose.htmlplanet.com/
>
> 3004 Grant Rd.
> REGINA, SK
> S4S 5G7
> 306-352-3620 or 1-888-29t-uner
>