[CAUT] temperature and pitch

[Jeff Tanner]

----- Original Message ----- 
From: "Fred Sturm" <fssturm at unm.edu>
To: "College & University Technicians" <caut at ptg.org>
Sent: Friday, December 18, 2009 11:21 PM
Subject: Re: [CAUT] temperature and pitch


> On Dec 17, 2009, at 2:22 PM, Jeff Tanner wrote:
>
>> Temp under the lid - in the dark - was 73.5 and the temp on the  table 
>> next to the piano was 73.0, bright lights in the room, etc.   That's half 
>> a degree.
>
>
> I don't think a difference in temperature that small is significant.  If 
> it gets above 2 degrees, then maybe you start to take notice, and  at some 
> point it actually affects things.

Remember, this was a space in a home where the temperature is pretty well 
maintained. The tuning actually happened between about 3 and 4:15pm or so, 
so most likely the room temp wasn't moving around much. I actually thought 
given those conditions that it was interesting that the temp inside the 
closed piano was a half degree warmer. I agree with you that a half degree 
probably isn't significant, but it is a sign that there is indeed an effect 
from the D/C system, especially if whoever posted was correct that the plate 
should have somewhat of a cooling effect.

The situation you described was one where the room temp dropped 10 degrees 
in just a few hours.  I was simply speculating that with the heat source 
directly beneath the the closed piano that the temp inside the piano would 
not have changed as much as the air outside it.  And perhaps if that were 
the case, your pitch didn't move as much as it would have otherwise.

Jeff