[CAUT] temperature and pitch

[Ron Nossaman]

Fred Sturm wrote:
> On Dec 16, 2009, at 6:21 PM, Ron Nossaman wrote:
> 
>> After the strings cool to nominally room temperature, they are very 
>> close to on pitch and tune easily and quickly.
> 
> 
>     Would it be fair to assume a relatively high ambient RH, or at least 
> one that is close enough to the target (42% for standard) that the 
> heating rods are firing a good bit of the time? My own experience (that 
> I was talking about relative to the piano I measured), now in early 
> winter NM with ambient RH in the 20s or below, is that the heating rods 
> are pretty inactive, so pretty much all you have adding heat is the 
> little tank rods, 10-15 watt or so.
>     I didn't mean to say that D/C systems couldn't cause 
> temperature/pitch problems, especially with uprights, especially in high 
> humidities. I haven't noticed it myself, but I can certainly imagine it 
> happening.

I didn't mean to say that DC systems either could or couldn't 
cause temperature/pitch problems either, under any humidity 
conditions, just that the ambient temperature of a functioning 
system under a floor length cover will, in my experience, make 
you wait for the strings to cool to room temperature before 
tuning when you pull the cover off. Since both the humidifier 
and dehumidifier use heat to do what they do, I expect the 
wait for the strings to cool down in a covered piano. It's a 
heads up observation on temperature, rather than humidity, effect.
Ron N