[pianotech] pitch of a piano

[paul bruesch]

Whoa whoa whoa...

When outside temperature goes down in the winter in northern climates like
Philly, heat from the furnace dries the air, causing wooden things
evaporate moisture and so shrink, which causes the piano to go flat.
Vice-versa in the humid northern climate during the summer. This air drying
due to furnace heat is due to warm air having increased capacity to hold
moisture. Winter outdoor humidity may be 50% and 10°F, but when that air is
heated to around 70°, the indoor relative humidity drops dramatically
because that now-warm air can hold more moisture.

On the other hand, as one respondent attempted to explain... if you tune a
piano, then heat a metal string(s), e.g. with a blow dryer, the string will
expand and the pitch will go flat. That is the principle used by that
self-tuning piano. The piano is manually tuned sharp initially, then the
self-tuning feature attempts to bring each string to proper pitch by
heating the wire by introducing electric current to cause it to heat.


On Sun, Feb 24, 2013 at 10:16 PM, <Jlmatt at aol.com> wrote:

> **
> No Wim and Marshall, it's the opposite!  Read what you wrote before you
> click "send"!
>
> Jean-Luc
>
>  In a message dated 2/24/2013 6:47:43 P.M. Mountain Standard Time,
> tnrwim at aol.com writes:
>
> Yes, Marshall, the pitch of a piano does go sharp when the temperature
> rises, or goes flat when the temperature drops. You understand, of course,
> only if the temperature in the room in which the piano is goes up or down.
> The pitch also goes up or down depending on the humidity level in the room.
>
> Isn't this something sort of basic that your learned in school? So why do
> you ask?
>
> Wim
>
>  -----Original Message-----
> From: Marshall Gisondi <pianotune05 at hotmail.com>
> To: pianotech <pianotech at ptg.org>
> Sent: Sun, Feb 24, 2013 3:28 pm
> Subject: [pianotech] pitch of a piano
>
>  Hi Everyone,
> I thought the pitch of a piano rises when the temp rises or goes sharp and
> when it's cold goes flat?
> Marshall
>
>
> *Marshall Gisondi*
> *MARSHALL'S PIANO SERVICE*
> *215-510-9400*
> *http://www.phillytuner.com *
>
>
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