Temperature Change affecting pitch

[Charly Tuner]

I assume even a minor drop/rise in pitch, due to humidity changes will make 
perfect unisons go out randomly, so it will be out of tune the next day. 
This is the problem I have at the store where I work...NO hunidity control, 
big picture windows allowing sunlight/heat to focus DIRECTLY on SB's! So I 
have a real dilemma trying to keep these pianos, the vast majority of them 
new, in tune from one day to the next..and of course the store pays me to 
tune them/PR them, basically once.

I was in Beverly Hills this past Sat, and I encountered a magnificent 
Bosendorfer Imperial 9ft. Concert Grand. I was there to have my original 
piano compositions performed by Maria Demina, a remarkable concert Pianist 
and good friend. I also had the session recorded by a sound engineer from 
KKGO FM, the Los Angeles Classical Radio Station. He recorded in "DAT" and 
later this week I will get a CD of the final edited performance, so I am 
pretty excited about that! I was told by  the owner that the piano had just 
been tuned only 3 weeks ago, but I found a great many unisons were quite 
out, so luckily I had brought my tuning tools, so i was able to do a quick 
touch-up tuning and all went well.

Terry

TErry

>From: Larry J Messerly <prescottpiano@juno.com>
>Reply-To: pianotech@ptg.org
>To: pianotech@ptg.org
>Subject: Re: Temperature Change affecting pitch
>Date: Mon, 27 Mar 2000 06:25:17 -0800
>
>Well Ron,
>It is dry here.  relative humidity went from 28 to 26% on a Radio Shack
>gauge.  Checking this morning total pitch drop is 0.2 and 0.3 cents.  So
>it seems like the immediate affect of temperature change is mitigated by
>time as the whole structure equalizes temperature.
>Larry
>
>On Mon, 27 Mar 2000 06:29:26 -0500 Ron Torrella
><rontorrella@worldspy.net> writes:
> > What was the relative humidity at 61 degrees? What was it when you
> > figured
> > the pianos' pitch had stabilized? Raising the room temperature
> > probably
> > lowered the rh and I'll bet that's what caused the pitch change.
> >
> > Ron Torrella, RPT
> > Ypsi, MI
> >
> > Larry J Messerly wrote:
> >
> > > 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
> >
>
>Larry Messerly, RPT
>Phoenix/Prescott

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