On 3/3/06 4:18 PM, "Ron Nossaman" <rnossaman@cox.net> wrote: > > >> "Wood with very low EMC will absorb ambient high RH very >> quickly. It's slower to dry out, and it takes higher temps and airflow to >> speed that process (read institutional conditions <g>). I can measure RH >> easier than EMC, and RH is good at predicting what will happen in the near >> and long term future." >> >> I gain from this that wood reacts very quickly on the intake and >> very slowly on the release. > > Not so. I've seen it assumed a lot of times, but have never > been able to find documentation to that effect from even a > minimally authoritative source. Both absorption and release of > moisture in wood is proportional to the difference between > wood MC and atmospheric RH%. > > Even so, keeping track of RH% readings is a very good > practical method of anticipating what the instruments' > reactions will be with the resulting MC levels, which are > lagging somewhat behind the RH% changes. > > Ron N > _______________________________________________ > caut list info: https://www.moypiano.com/resources/#archives > My experience leads me to this conclusion based on pitch change speed. Maybe, though, it is because I more often experience sudden spikes up, due to rain, while the drops in RH are more gradual. If somebody regularly takes a piano from a humidity controlled space onto a dry stage, and is able to track what happens over the course of, say, 24 hours, together with the data for RH on stage and RH in the controlled space, I would be very, very interested to know what is observed. Regards, Fred Sturm University of New Mexico
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