Temperature Change affecting pitch

[pryan2]

I learned the hard way that temperature has a immediate effect on pitch.
When I go into one of the showrooms to tune a piano, I click on the air
conditioning (I'm in South Florida), proceed to strip mute a piano and begin
tuning middle strings with the SAT.  After getting half way through the
piano, I go back to where I started and re-check my work. All the red lights
are spinning sharp now. What do I do now? Start over or let them go?    What
I do now is turn the AC on in advance and let the showroom and pianos to
cool down before starting.

Phil Ryan
Miami Beach
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----- Original Message -----
From: "Larry J Messerly" <prescottpiano@juno.com>
To: <pianotech@ptg.org>
Sent: Sunday, March 26, 2000 7:15 PM
Subject: Temperature Change affecting pitch


> Just for my own information, when I came into my store this morning I
> took pitch readings on two grands at 61degrees F. then turned on the
> heating system and raised the temperature to 68 degrees.
>
> The 6' Kranich and Bach dropped pitch 3.2 cents initially and then when
> (I presume) the plate temperature rose ended up 1.6 cents flat of where
> it had begun the morning.
>
> The 5'3" George Steck initially dropped 0.4 cents then continued to fall
> to 1.2 cents from where it had been.
>
> They have not changed any more over the last hour.
>
> No real problem or question here, just thought it was interesting.
>
> Larry Messerly, RPT
> Phoenix/Prescott
>